Articles by tag: design

Articles by tag: design

    Finishing the Chassis

    Finishing the Chassis By Kenna and Janavi

    Task: Build a Chassis

    We have been working on this chassis, on and off, for over three months. Just about every part of it has been built, disassembled, and rebuilt more than twice. In out last post, we had thought the wheels were ready to go. However, various parts had been put on backwards or were unusable so we had to do everything over again. Once we had rebuilt, we realized that there were even more issues. So we fixed those and built them again. Both of us could probably assemble wheels, motors, and chains in our sleep.
    Now that the robot has wheels, we started on attaching the REV expansion hub and battery. The chassis is square, but has an asymmetrical structure of tetrix bars. Attaching the battery was the simple part since previous version of the robot had a 3D-printed battery holder that would be screwed on. After a short search, we found it in a box of 3D-printed parts whose prime was long over. There was no way to effectively place the expansion hub on the tetrix rails. Instead, we attached a thin plank of wood to two parallel bars, drilled a couple holes, and screwed the hub on.
    Overall, it is a very no-frills chassis. We had to cut most of the side shields off because they were becoming more of an obstruction than an aid. Though it was a pain to build and rebuild every aspect of the chassis, we gained a lot of building experience out of one robot. We chose a relatively difficult design to built for the first time but, in the end, it was functional and that's all we can really ask for.

    Next Steps

    Though the physical robot has been built, it has no code. Both of us will be learning how to program a basic pushbot.

    Swerve Drive Experiment

    Swerve Drive Experiment By Abhi

    Task: Consider a Swerve Drive base

    During the entire season of Relic Recovery, we saw many robots both in and outside our region that had a swerve drive. As Iron Reign, we never considered a swerve drive in the past but seeing all the robots, I wanted to see if it was maybe possible. One motivation was that I didn't like how slow mechanums were. Swerves generally use traction wheels and create a faster speed than usually can be found with mechanum. Also, it seemed as if swerve could provide the mobility neccessary that a mechanum drive provided. This is why I wanted to consider the possibility of a swerve drive and why I did more investigation.

    I first came across the PRINT swerve for FTC by team 9773. They had a very detailed explanation of all the parts and assebly tools. After reading into it more, I decided that the system they created wasn't the best. First, the final cost of the drive train was very expensive; we did not have a very high budget despite help from our sponsors. If this drive train didn't work for some reason after playing with it over the summer or if the chassis didn't make sense to use in Rover Ruckus, we would have almost no money for an alternate drive train since we wanted to presearve Kraken. Also, they parts used by 9773 invovled X-rail rather than extrusion rail from REV. This would cause problems in the future as we wold need to redesign the REVolution system for X-rail. In the end, I decided this was not worth it to pursue.

    After further investigation, I found a chassis by team 9048. The swerve they developed looked like a more feasible option. By using REV rail and many of the parts we had, I thought this would be a possible prototype for Iron Reign. Because they didn't have a parts list, we had the find the rough estimate of cost from the REV and Andymark websites. Upon further analysis, we realized that the cost, though cheaper than the chassis of 9773, would still be a considerable chunk of our budget. But I am still motivated to find a way to make this happen.

    Next Steps

    Possibly scavenge for parts in the house and Robodojo to make swerve modules.

    Swerve Drive Prototype

    Swerve Drive Prototype By Abhi and Christian

    Task: Build a Swerve Drive base

    During the discussion about swerve drive, Imperial robotics, our sister team, was also interested in the designs. Since we needed to conserve resources and prototype, I worked with Christian and another member of Imperial to prototype a drive train.

    Due to the limited resources. we decided to use Tetrix parts since we had an abundance of those. We decided to make the swerve such that a servo would turn a swerve module and the motors would be attached directly to the wheels. This system would be mounted to a square base. We decided to go ahead and make the base.

    Immediatly we noticed it was very feeble. The servos were working very hard to turn the heavy module and the motors had trouble staying aligned. Also, programming the train was also a challenge. After experimenting further, the base even broke. This was a moment of realization. Not only was swerve expensive and complicated, we also would need to replace a module really quickly at competition which needed more resources and an immaculate design. With all these considerations, I ultimately decided that swerve wasn't worth it to use as a drive chassis.

    Next Steps

    Wait until Rover Ruckus starts so that we can think of a new chassis.

    Big Wheel Ideas

    Big Wheel Ideas By Janavi

    Task: Create a Unique Chassis

    This summer, we're working on creating unique chassis that are outside of our comfort zone. Often we choose safe bases - opting for ones that we have tried in the past and know work. But, taking the opporunity to explore unique bases allows us to see their performance. One of our ideas is for a two-wheeled robot, with two large wheels and one, smaller, non-motorized omniwheel. I think that this 2-wheeled robot would be a good opportunity for Iron Reign, as we know that our robot has to be lighter than the Relic Recovery robot and a non-mecanum drive would be much lighter.

    Next Steps

    To create this chassis we are planning on using two lightweight wheels along with a square body made out of polycarb. We plan to minimize metal in our design rather opting for materials that are just as functional but weight less.

    Chassis Flyer

    Chassis Flyer By Ethan

    Kraken

    This is Iron Reign’s world-championship robot from last season. The basic rundown is this:

    • Weight - 42 lbs
    • Size - 18x17.8x17.5 inches
    • Drive - Mecanum
    • Main parts kit - REV

    Iron Reign uses two design processes in conjunction with each other to create efficient and reliable parts. First, we use the Kaizen design process, also used in industrial corporations such as Toyota. The philosophy behind Kaizen is the idea of continual improvement, that there is always some modification to each system on our robot that will make it more efficient or more reliable. As well, design competitions are a focal point of Iron Reign’s design process. In these design competitions, team members choose their favored designs that all complete some field challenge, and build them individually. Upon completion of each mechanism, the designs are tested against each other, considering weight, maneuverability, reliability, and efficiency.

    An example of these design processes working in conjunction is the process of designing our cryptobox intake system. One person had the idea to build an arm-style grabber seen on many current competition robots. His design, however, included shorter arms for space’s sake and a more compact lift system than normal. The second person decided to build a unique conveyor-belt system which used friction to hold blocks in space and move them vertically. Through the competition, we determined that the prior design was more efficient and took up less space than the latter, so we settled on his design, adding in a linear slide for lifting at the end of the process. Then, Kaizen comes in. Through firsthand experience in scrimmages, we learned that the grabber system isn’t as reliable as we thought when first testing. So, we have designed a new grabber system that moves like the arms did previously, but also rotate with soft spikes attached to hold blocks with friction better without damaging them.

    As this soft-spike system ceased to perform to our expectations, we looked to other mechanisms to pick up and deliver blocks effectively. We created a new grabber that still used the rotating systems of the soft-spike, but instead, we used custom 3D printed “octopuckers” which had a much tighter grip on the glyphs. As well, inside the gripper, we created a custom “lift” made out of NinjaFlex so that the blocks could be moved up and down internally in the gripper, eliminating our need for stacking.

    Later, we further improved upon the grabber design, attaching it to a conveyor belt so that we could move glyphs all across our robot in order to score higher, using our REVolution system. This is the most ambitious use of our REVolution system yet, and we strongly encourage the reading judges to view it at the pits.

    BigWheel

    The main purpose of this robot is to see if larger wheels will give us an advantage in the competition. Right now, we’re guessing that the competition field will have debris, and we hope that the large wheels will perform better in this environment.

    • Size: ~18x18 in
    • Wheels - 8in large, regular omni wheels in front
    • Part System: Custom parts

    Garchomp

    For skill development we have newer builders replicating the chassis portion of our competition robot (Kraken). This one will not be weighed down by the additional upper structure of the competition robot and so should be a closer comparison in weight class to most of the other chassis designs under consideration here. Garchomp has a simplistic design and is nothing more than mechanums, rev rails, motors, sprockets, wires, and a rev hub. The large mechanums are held together using side plates from the 2017-18 competition season. These are geared up to neverest 40:1 motors.

    • Size: ~18x18 in
    • Wheels: Mechanum
    • Part System: REV
    • Motors: Neverest 40:1

    Summer Chassis Project - July Meeting

    Summer Chassis Project - July Meeting By Kenna, Ethan, Charlotte, Karina, Shaggy, and Abhi

    Task: Compare & Collaborate on Chassis

    At Big Thought's offices in downtown Dallas, three teams met. Technicbots (Team 8565), EFFoRT (Team 8114), Schim Robotics (12900), and Iron Reign are all part of the North Texas Chassis Project. The goal is for each team to create any number of chassis and improve their building skills by learning from the other teams.

    The meeting began with an overview of all teams' progress. Each team presented their thought process and execution when creating each bot and discussed why/how everything was done. At the end, we all reviewed the rule changes for the 2018-19 season. Once all questions had been asked and answered, testing began.

    Austin Lui of Technicbots gets their chassis ready for testing.

    Using leftover tiles from last season, we set up a small field in Big Thought's blue room. Technicbots provided a ramp to do enhanced testing with. All teams plan on testing:

    • Forward speed
    • 3 second turn
    • Up/Down ramp
    • Balancing stone
    • Weight-pulling
    • Straight line drift
    • 90/180° turn offset

    Connor Mihelic of EFFoRT adds some finishing touches.

    We know from Google Analytics that our website has about 200 visitors a month but we rarely meet the people who read and use our blog posts. Today, we got to meet the mentors of Team 12900 from a middle school in Plano, TX. When they and their students were starting out as a team, they utilized our tutorials and journal. Apparently their teams members are avid followers of our team, which was very meaningful to hear. Some non-FTC friends visited as well and were introduced to cartbot.


    Terri and Grant Richards of Schim Robotics.

    Next Steps

    Using what we learned from the other teams, we will begin to improve all of our chassis. Most of them are at varying levels of completion so now we want to concentrate on getting all of them to the same level of functionality. Garchomp is, notably, the most behind so he will be getting the most attention from here on out.

    C.A.R.T. Bot Summer Project

    C.A.R.T. Bot Summer Project By Evan, Abhi, and Janavi

    Task: Enhance our robot-building skills

    At Iron Reign, we hate to waste the summer since it’s a great time to get all the ridiculous builds out of the way. Thus, we created C.A.R.T. Bot (Carry All our Robotics Tools). Our constant companion these last few seasons has been our trusty Rubbermaid utility cart which has been beaten and abused, competition after competition, as it carried all our tools and robots. Because of all of this, we decided it was time to show the cart a little love, and in typical Iron Reign fashion, we went all out and turned it into a robot.

    Our first step was to switch out the back wheels on it to elf-sized bicycle wheels, allowing us to take on the mightiest of curbs and motorize it. To attach the wheels, a four foot or so cylinder of threaded steel was inserted in holes on either side of the cart. Two slots were cut out in the bottom for the wheels and they were eventually slid on, but not after 3D printed mounts for sprockets were attached to the wheels, enabling us to gear them in a one to one ratio with the sprocket attached to the motors, which consisted of two SIM motors commonly found on FRC robots.

    Before we used SIM motors, we attempted to power the cart using two Tetrix motors which were geared for speed but, due to load, barely moved at all. Besides a lack of power, they also tended to come out of alignment, causing a terrible noise and causing the cart to come to a stall. This was quickly scrapped. To mount the motors, we used two pieces of aluminum bars and bolted them to the motors, then screwed them to the floor of the cart, aligned with the wheels. We chained them together and got about powering the system. We got two 12-volt batteries and chained them in parallel so as to not overload the system, and hooked them up to a REV hub. Then, we ran them through a switch and breaker combination. We connected the motors to the rev hub and once we had it all powered up, we put some code on it and decided to take it for a spin.

    It worked surprisingly well, so we went back in and put the finishing touches on the base of Cart Bot, mainly attaching the top back on so we could put stuff on top of it, and cutting holes for switches and wires to run through, to make it as slick as possible. We added a power distribution station to assist with the charging and distribute current to any device we decided to charge on the cart. We will eventually hook this up to our new and improved battery box we plan on making in the few spare moments we’ll have this season, just a quick quality of life improvement to make future competitions go smoothly.

    Next Steps

    Our cart box isn’t done yet, as we intend to make a mount for a solar panel, which we will be able to charge the cart during the downtime in competitions (only if there’s a good window we can park it next to). The cart wasn’t just about having a cool new and improved cart that we don’t have to push (which it is), it also was a test of our engineering skills, taking things that never should have been and putting them together to make something that we will utilize every competition. We learned so much during this experience, I for one learned how to wire something with two batteries as not to destroy the system, as for everyone else, I can’t speak for all but I think we learned a very important lesson on the dangers of electricity, mainly from the height of the sparks from an accidental short that happened along the way. Despite this, the cart came out great and moves smoother than I ever could have hoped. The thing is a real blast and has provided a lot of fun for the whole team, because yes, it is rideable. We predict the speed it’s set at is only a fifth of its full potential speed, and since it already goes a tad on the fast end we don't intend to boost it anymore while there’s a rider on it. Overall, the project was a success, and I’m personally very proud of my work as I’m certain everyone else is too. Come to see it at our table, I really think it’s worth it.

    Garchomp Part 2

    Garchomp Part 2 By Janavi and Kenna

    Task: Build the Chassis

    So, we thought we finished but we were wrong, oh so wrong. As you saw in our last post, we thought our chassis was functional. However, after leaving it alone for over a week, Garchomp decided that it didn't want to work any more and 3 out of 4 of the chains came off.

    So, we started to diagnose the problem. We noticed that the old REV rails we were using had dents in them, which caused the motors to shift, therefore causing the chains to come off the gears.

    We decided to replace the REV rails. First we loosened all of the screws on the current bar, carefully slid it out, and replaced it with new bars. This solved one of many problems that we had somehow missed when building our chassis. After fixing all of the chains and confirming that each of them were individually working, we re-attached all of the cables to the robot and ran the code. We discovered that not all of the wheels were running at the same speed because our robot kept on moving in circles. After checking that the motors were working, we discovered that it was our encoder cables that were plugged in wrong. But finally... After fixing that, and after many, many hours of trying to fix the chassis, we finished! Now, I think, we can safely say our chassis is complete.

    Next Steps

    We will try out more tests on the robot and make sure that it is up to par with our past robots.

    BigWheel CAD

    BigWheel CAD By Ethan

    Task: Create a mockup for BigWheel

    We've been working on a design for the chassis workshop for quite a while now. We already presented it at the first meeting, and now we need to work on the other components of our presentation: the weight testing, torque calculations, speed testing, and finally, a chassis model. To do the last one, we made a simple model in PTC Creo.

    Bigwheel Presentation

    Bigwheel Presentation By Arjun and Karina

    Task: Present about Garchomp

    As a new freshman on Iron Reign, I took on the responsibility of a robot we called Bigwheel. Karina and I worked on getting the robot into something that could be put through load tests, meaning tightening the chain, fixing misaligned sprockets, and getting the wiring together. We participated in the Chassis Presentation workshop hosted by technicbots for teams all around the North Teas region to work on one or more chassis, perform various tests with them and then present their findings. We presented our chassis Bigwheel, which is driven by 2 large 8-inch wheels, with a pair of 2 free-spinning Omni wheels in the back. This can be seen in the presentation below:

    To create our chassis we used 2 8-inch wheels, each driven by 2 Neverrest 60 motors. There are also two free-spinning omni wheels in the back. The robot uses REV rails and plexiglass for it's main body.

    Our first test is the 5-second distance test. Our robot had a lot of torque due to the Neverrest 60 motors, so it moved slower than other robots, but was unaffected by the additional 30lbs weight.

    Our second test is the 3-second turn test. Again, some other robots could turn better faster than us. However, due to having no proper mechanism for restraining our weights, along with other mysterious problems such as battery disconnections that only happened during this test, we were unable to try this test with load, however we presume that due to the torque, the results should be similar to those without load. Our center of rotation is also off due to only the front two wheels being powered. As such, the back of the robot makes a wide arc as it turns.

    Our next few test results are unremarkable.

    Our robot had a lot of sideways drift, mostly due to bad build quality. If we intend to use it during the season, we will try to fix this.

    Overall, our chassis performed well under load, but could use a little speed boost. If we want to further develop it, we plan to use Neverrest 20s with more torque on our extarnal gear ratio, so we can get more speed out of it.

    Garchomp Presentation

    Garchomp Presentation By Janavi and Kenna

    Task:

    After months and months of Kenna and I working on our chassis, all of our work finally accumulated in our presentation. We participated in the Chassis Presentation workshop hosted by technicbots for teams all around the North Teas region to work on one or more chassis, perform various tests with them and then present their findings. We presented our Chassis Garchomp who is a mechanum wheel chassis as can be seen in the slide photos below.

    Presentation

    To create our chassis we used 4 never rest 40 motors one for each wheel and the structure of the chassis was created by using tetrix rails. We connected the wheels to the motors by using a 1:1 gear ratio. While there are many benefits to using a gear ratio for your wheels be forewarned that if your wheels are not perfectly alligned attaching your chains to mechanum wheels will become a living nightmare as can be seen in our previous posts.

    One of the reasons that attaching the chains was so difficult for us was because we discovered that because we had used wooded sides instead of the aluminium sides that Kraken used our wheels became misaligned to the who different types of wood used for the two sides.

    Our robot is not able to turn relatively fast but as can be seen on Kraken it is able to hold alot of load and move at a constant speed

    Since this chassis was designed for last years competition it is able to consistently drive onto the balancing stone

    Rover Ruckus Brainstorming & Initial Thoughts

    Rover Ruckus Brainstorming & Initial Thoughts By Ethan, Charlotte, Kenna, Evan, Abhi, Arjun, Karina, and Justin

    Task: Come up with ideas for the 2018-19 season

    So, today was the first meeting in the Rover Ruckus season! On top of that, we had our first round of new recruits (20!). So, it was an extremely hectic session, but we came up with a lot of new ideas.

    Building

    • A One-way Intake System
    • This suggestion uses a plastic flap to "trap" game elements inside it, similar to the lid of a soda cup. You can put marbles through the straw-hole, but you can't easily get them back out.
    • Crater Bracing
    • In the past, we've had center-of-balance issues with our robot. To counteract this, we plan to attach shaped braces to our robot such that it can hold on to the walls and not tip over.
    • Extendable Arm + Silicone Grip
    • This one is simple - a linear slide arm attached to a motor so that it can pick up game elements and rotate. We fear, however, that many teams will adopt this strategy, so we probably won't do it. One unique part of our design would be the silicone grips, so that the "claws" can firmly grasp the silver and gold.
    • Binder-ring Hanger
    • When we did Res-Q, we dropped our robot more times than we'd like to admit. To prevent that, we're designing an interlocking mechanism that the robot can use to hang. It'll have an indent and a corresponding recess that resists lateral force by nature of the indent, but can be opened easily.
    • Passive Intake
    • Inspired by a few FRC Stronghold intake systems, we designed a passive intake. Attached to a weak spring, it would have the ability to move over game elements before falling back down to capture them. The benefit of this design is that we wouldn't have to use an extra motor for intake, but we risk controlling more than two elements at the same time.
    • Mechanum
    • Mechanum is our Ol' Faithful. We've used it for the past three years, so we're loath to abandon it for this year. It's still a good idea for this year, but strafing isn't as important, and we may need to emphasize speed instead. Plus, we're not exactly sure how to get over the crater walls with Mechanum.
    • Tape Measure
    • In Res-Q, we used a tape-measure system to pull our robot up, and we believe that we could do the same again this year. One issue is that our tape measure system is ridiculously heavy (~5 lbs) and with the new weight limits, this may not be ideal.
    • Mining
    • We're currently thinking of a "mining mechanism" that can score two glyphs at a time extremely quickly in exchange for not being able to climb. It'll involve a conveyor belt and a set of linear slides such that the objects in the crater can automatically be transferred to either the low-scoring zone or the higher one.

    Journal

    This year, we may switch to weekly summaries instead of meeting logs so that our journal is more reasonable for judges to read. In particular, we were inspired by team Nonstandard Deviation, which has an amazing engineering journal that we recommend the readers to check out.

    Programming

    Luckily, this year seems to have a more-easily programmed autonomous. We're working on some autonomous diagrams that we'll release in the next couple weeks. Aside from that, we have such a developed codebase that we don't really need to update it any further.

    Next Steps

    We're going to prototype these ideas in the coming weeks and develop our thoughts more thoroughly.

    Testing Intakes

    Testing Intakes By Ethan and Evan

    Task: Design a prototype intake system

    In our first practice, we brainstormed some intake and other robot ideas. To begin testing, we created a simple prototype of a one-way intake system. First, we attached two rubber bands to a length of wide PVC pipe. This worked pretty well, but the bands gave way a little too easily.

    For our next prototype, we attached a piece of cardboard with slits to a cup approximately the size of a cube or block. It operates similarly to a soda cup lid with a straw hole. An object can go in, but the corners of the hole spring back so that it can't escape.

    Next Steps

    We probably won't go with this design - we'd have issues seperating the different kinds of game elements, and it may be too slow to feasibly use. But, its a first step and we'll see what happens.

    Brainstorming Two - Enter the Void

    Brainstorming Two - Enter the Void By Evan, Abhi, and Janavi

    Task: Have a 2nd brainstorming session

    Last week, we had a lot of new recruits show up for the FTC kickoff. In fact, a bit too many. Luckily for us, we either scared them off or they realized that they'd like to move to FRC. So, today's session was a bit more managable, and we were able to break down into some new building tasks.

    Intake System 3 - TSA Bag Scanner

    If any of y'all have ever been on an airplane, you've gone through airport security. This part of our robot is inspired by the bag-scanning machine, more specifically the part at the end with the spinning tubes. The basic design would be like a section of that track that flips over the top of the robot into the crater to intake field elements.

    Intake System 4 - Big Clamp

    This one is self-explanatory. Its a clamp, that when forced over a block or a cube, picks it up. It's not that accurate, but it's a good practice idea.

    Lift 2 - Thruster

    We want to make lifting our robot easy, and we're thinking of a slightly different way to do it. For our new lift idea, we're installing a vertical linear slide that forces the robot upwards so that we can reach the lander.

    Next Steps

    We're working on building these prototypes, and will create blog posts in the future detailing them.

    Chassis Brainstorming

    Chassis Brainstorming By Ethan and Evan

    Task: Brainstorm chassis designs

    At the moment, we've used the same chassis base for three years, a basic mechanum base with large wheels. However, we don't really want to do the same this year. At the time, it was impressive, and not many teams used mechanum wheels, but now, its a little overdone. So, as the true hipsters of FIRST Tech Challenge, we want to move onto something new and fresh.

    Thus, we have BigWheel. We used this as a practice design, but we ended up really liking it. It starts off with two large rubber wheels, approx. eight inches in diameter, mounted at the back and sides of the robot. Then, we have two geared-up motors attached to the motors for extra torque and power. In the front, we have a single omniwheel that allows our robot to turn well.

    Proposed Additions

    First, we need to add an intake system. For this, we're considering a tension-loaded carwash that can spring out over the crater wall. It'll pull elements in and sort them through our intake using our seperator, which we will detail in a later post. Then, the robot will drive over to the lander and lift itself up. Since the main segment of the robot is based off of two wheels, we're attaching a telescoping slide that pushes off of the ground at the opposite end and pivots the front of the robot upwards. Then, the intake will launch upwards, depositing the elements in the launcher.

    Next Steps

    We need to create a proof-of-concept for this idea, and we'd like to create a 3D model before we go further.

    Hanging Hook Prototype

    Hanging Hook Prototype By Abhi, Ethan, Justin, and Janavi

    Task: Design a hook for pulling the robot on the lander

    Today, we designed a basic prototype to hang the robot. We designed it, like all our parts, in PTC Creo, and printed it in nylon with ~80% infill. The hook was designed to minimize material used while also being strong enough not to stretch over time. First, we tested it by hanging ~20 lbs of material off of it for one minute. This worked, but a little too well. While the nylon piece remained undamaged, the metal bracket it was supported by bent at a ninety degree angle. So, we had to pursue further testing.

    For our next test, we plan to hang a mass outside for a week. Dallas weather has been extreme lately, with a lot of rain, humidity, and heat. This will be the ultimate stress test; if one of our pieces can survive the outdoors, it can survive just about anything.

    Next Steps

    We're probably going to have to reprint this to be a bit more fitting for our robot, but its a good start and it works great so far.

    BigWheel Chassis

    BigWheel Chassis By Evan

    Task: Work on a possible chassis

    We have our first qualifier coming up real soon, and to get ready we decided to get a robot into gameworthy shape. So far we have a few chassis from our work over the summer, so I decided to start on a neat little competition bot out of the one we called Bigwheel, named for its two big drive wheels in the back. The idea for this robot is that it has a collection system that extends into the crater, and folds up on top of the robot. It reaches in with the collection arm, and grabs the blocks/glyphs, drives backwards and flips vertically using the drive wheels as a point of rotation. Here’s a basic sketch of what that looks like.

    The way this will be achieved is with a spring loaded lever connected to the omni wheel that makes up the holy trinity of wheels. So far I have pieced together the arm that reaches into the pit, which is powered by two NeverRest 60s and geared in a two to one ratio to significantly increase the torque. Between the two arm I plan for a horizontal beater bar to intake blocks and a slide attached to a servo to separate blocks and balls based on their size. The idea is to have a way of sorting based off of the physical shape rather than by digital sensing means. The more that can be done purely off the shape of the elements, the better.

    Next Steps

    So far, not much has gone into materializing the lever since this was made while the rest of the team was at an outreach event. Next week, the team will have to make some serious progress since there will be more hands to build. My hope is that the lever will come about soon, even if in its most infant stage, and that some semblance of a functioning robot can be game tested in the next few weeks, just in time for a scrimmage and potentially an early qualifier.

    Intake Sorter

    Intake Sorter By Abhi

    Task: Design a sorter for the balls and blocks

    We've been brainstorming ways to sort the gold and silver pieces, and here's our first one. It's a little bulky, but it's a start.

    The way this works is that when this piece is mounted and both blocks and balls are run over it, the balls run down the top and don't fall in the collector, but the blocks fall in the holes. We modelled this design in PTC Creo, then printed it in ABS.

    Next Steps

    This is a little too bulky, so we're going to have to find a smaller and simpler way to sort game pieces, but it's a start. In the future, we're going to minimize this and probably move to a smaller sorting mechanism.

    Designing Wheel Mounts

    Designing Wheel Mounts By Justin

    Task: Create wheel mounts for our Mini-Mecanum chassis

    Today, we modelled two possible designs for mini-mecanum wheel mounts. The purpose of the mounts is to hold a churro or hex shaft in place to mount mecanum wheels to. The first design was a 6cm by 6cm square with rounded edges that was 5mm thick. A hexagon was removed from the center to hold the churro that supports the mecanum wheel. This design, when printed on low infill, allowed the churro to rotate when enough force was applied. We modeled this design off of the wheel mounts on Kraken and Garchomp; the only differences are the size and material. Because we will be 3D printing these mounts, material efficiency is very important. This mount design used a lot of material to make a prototype, meaning a finished stable mount would need even more material to prevent the churro or hex shaft from slipping.

    Taking these problems into account, we designed a different way to mount the wheels. The new version can mount underneath a REV Rail and hold the shaft or churro perpendicular to the rail. This design uses much less infill than the previous one because of how small the mount is, and because the REV Rail also acts as support to prevent the churro or shaft from spinning. The mount also allows the mini-mecanum wheels to be mounted as close to the frame as possible, which can help make the robot more compact. This design will allow us to easily mount mini-mecanums to our frame, while using minimal filament and taking up very little space.


    Next Steps

    We need to build the full mini-mecanum robot to judge whether these designs will fully work.

    Designing the Corn Cob Aligner

    Designing the Corn Cob Aligner By Ethan and Abhi

    Task: Design an aligner for the beater bar

    The ice cube tray is 9 holes wide and each hole is 16.50mm wide and long. Using these measurements, we created an aligner that would cause the ice cube tray to roll into a cylinder.

    However, this system has issues. First, we wanted the edges to still be mildly compliant, and this wheel filled out the edge rows to full depth, making them a little too tough. Plus, they made the silicone height too variable, so that we couldn't solely pick up the balls. So, we designed a second aligner with shorter spokes so that the edges would be fully compliant while still being held securely.

    Next Steps

    We need to finish up the corn-cob beater bar, but after that we'll be able to start testing.

    Corn-Cob Intake

    Corn-Cob Intake By Ethan and Abhi

    Task: Design an intake system unique for balls

    Right now, we're working on a static-deposit system. The first part of this system is having an intake mechanism that passively differentiates the balls and cubes, reducing complexity of other parts of the design. Thus, we created the corn-cob intake.

    First, we bought ice-cube trays. We wanted a compliant material that would grip the particles and be able to send them into a larger delivery mechanism. Last year, we looked at a silicone dish-drying tray as a compliant way to grip the blocks. This year, we're thinking about doing the same with the ice cube trays.

    First, we designed a wheel which' spokes would fit into the holes on an ice cube tray, allowing the tray to stay static while still being compliant in a cylindrical shape. Then, we can put axle hubs through the center of the wheel, allowing us to mount the wheels on a hexagonal shaft. Then, we can mount a sprocket on that, allowing the bar to be rotated for intake.

    Next Steps

    We need to mount this on our robot and design a way to deliver the field elements. We're also going to go into more detail on the ice cube mounts in a later blog post.

    Team Marker Fun

    Team Marker Fun By Karina

    Task: Create the Team Marker

    Last week, we decided to take up the task of creating the team marker, a simple project that would surely be overlooked, but can score a significant amount of points. We wanted the marker to be meaningful to the Iron Reign, but also follow the team marker rules. To start, we made a list of ideas, and considering how ridiculous we all are at Iron Reign, this is what we came up with:

    Last season, Ducky (as seen in idea #4) brought Iron Reign good luck whenever the drivers squeezed them, and so we knew that we wanted to incorporate Ducky into whatever the final product would be. Some team members suggested fusing together multiple rubber duckies to fit the dimensions in the rule book. I had a better idea. I thought, "Why not put Ducky in a box?" However, trapping Ducky in a box would prevent us from ever squishing Ducky again (as long as they are trapped in the box). But then an even better idea came up: "Why not put Ducky in a cage?" And so we got to work making a cage for Ducky, one that we could release them from or reach in to whenever we need a squish for good luck.

    We cut two pieces of 3.5 inch x 3.5 inch polycarb to serve as the ceiling and floor of the cage. Then we used 8 standoffs, in pairs of two at each corner of the cage, to serve as the bars. To not waste anymore standoffs, we used zipties as the cage bars. Additionally, the flexibility of the zipties allow us to squeeze Ducky out of the cage from inbetween the bars. In the end, Ducky looked like the most happy prisoner we've ever seen:

    Next Steps

    With the team marker built, we need to test how well it does its job (staying in one peice for the duration of a match hopefully). It's survived many nights now in the our coach's house, which is no small feat, with all the children running about and constantly misplacing things. Once we have an intake system working for the minerals, we will need to test how compatible it is with Ducky in a Cage. Lastly, we need to decorate Ducky's cage, including our team's number (6832).

    Another Design Bites the Dust

    Another Design Bites the Dust By Ethan

    Task: Discuss a new rule change

    At one point, we were thinking about creating a "mining facility" robot that stays static within the crater and delivers the blocks into the mining depot. In our eyes, it was legal as it would hold as many blocks as possible inside the crater but only deliver two at a time outside. It would be super-effiecient as we would be able to stay within the crater, and not need to move.

    However, fate has struck. Earlier this week, we recieved this message:

    The rule limiting control/possession limits of minerals has been updated to indicate that robots may _temporarily_ hold more than 2 minerals in the crater, but must shed any excess over prior to performing any other gameplay activities (which would include scoring).
    says that "Robots In a Crater are not eligible to Score Minerals". Per the definitions of "In" and "Crater", if _any_ portion of a Robot is in the vertical area above the crater (extending from the field walls to the outside edge of the Crater Rim), then scoring a Mineral results in a Major Penalty.
    says that Robots may not obstruct another Robot's path of travel in the area between the Lander and a Crater for more than 5 seconds.

    This means that we couldn't do a static mining facility as we cannot score within the crater. Since we'd have a portion of the robot always in the crater, the existence of our robot would be a major penalty.

    Next Steps

    So, we need to rethink our robot. We still want to create a semi-static robot, but we need to redesign the intake portion.

    Mining Base 2.0

    Mining Base 2.0 By Ethan

    Task: Rethink our static robot idea

    So, our dream this year is to create a static robot. Last week, we found out about a rule change that would prevent our mining robot from staying within the crater. Naturally, we found a way around this, leading us to the Mining Base 2.0.

    The robot will be fixed under the lander's hooks, and have a horizonal and vertical linear slide attached to it. The horizontal linear slide would reach over the crater walls and pick up the silver balls, and shoot them up towards the lander. On the lander, our vertical linear slide would create a backboard that would allow the balls to fall into the lander. This wouldn't violate the rules as we wouldn't be in the crater.

    Next Steps

    We need to start on the designs of this robot, but to do this, we first need to create a working chassis.

    BigWheel+

    BigWheel+ By Evan

    Task: Continue work on BigWheel

    Since the last time we have discussed Bigwheel, the robot has gone through a few major changes. First and foremost, it now has a flipper arm. Since the robot itself is the lift mechanism, we had to put a lot of work into the design of the flipper. Right now it is a 10 inch REV rail attached to two of the largest REV gears you can buy, with a custom 3D printed mount housing an omni wheel pair. Right now it’s turned by two pairs of the smallest REV gears you can buy creating a 3:25 gear ratio. It’s a bit odd, but it increases torque which is what we’re going for, the philosophy being that it’s better to be smooth than to be quick, as a quick robot is weaker and less controllable. On top of the flipper, we’ve added extra supports on the arm mounts, as when we went to the Hendricks scrimmage, we found that the two sides were out of alignment, and one was bending more forward than the other, making the arm bend unevenly to one side and throwing the whole robot out of alignment. The next step is to strengthen the arm itself, as the two sides have a tendency to want to do their own things, mainly the side with the intake motor mounted to it. Since the supports have been put in though, Bigwheel has been functioning much better, and the arm no longer flops to one side. General wire management has also taken place, as previously the wires went every which way and created an infuriating mess that had the potential to get caught in the gears. Personally I’ve noticed that we’re a tad out of touch with gears right now, none of our other robots have sported them to much degree. We’ve been really in touch with sprockets though, since they’ve featured heavily in our designs the past two years. That’s just an observation, and since my first awareness of this, I’ve seen our gear savvy grow.

    Next Steps

    Bigwheel was built on a bit of a shabby base, mostly being made of a piece of polycarb and some aluminum bars, and not giving much in terms of change. We’ve cut here and there, drilled a few holes, unattached and re-attached a couple of things, but in all it’s a very stiff robot, and doesn’t lend itself to fluidity of design. That’s why we plan on making a second version of this base, hopefully with thinner polycarb and more secure sides that have been welded together but can be removed more easily. The exact design is still being modeled, but we have a direction to jump off from, and I believe we can make that leap to a better robot.

    Mini Mechanum Chassis

    Mini Mechanum Chassis By Janavi and Justin

    Task:

    To everyone's suprise, Garchomp didn't pan out. But, practice makes perfect, and that’s what we are going to do: create new chassis until we find one that works!

    When looking for inspiration for a new chassis, we found the mini mechanum wheels that we had been fiddling with last season but eventually scrapped in favor of the larger wheels that can be seen on Kraken.

    In the past, Iron Reign has been infamous for creating robots that barely fit within the sizing cube by a fraction of an inch, so we decided to take a different approach this time. We built a low-laying 6" x 6" robot to counter our older approaches. However, this new design meant that many of the pieces we had created in previous competitions would be unusable due to the changes in size and structure. For example, the way we affixed the wheels to the frame didn't work, as the axles were too big and the wheels were too small to use with our former wheel mounts. As well, these new mini mechanum wheels came with almost frictionless bearings, but the axle that fit within these bearings was hexagonal, unlike the round ones we usually use.

    Justin first designed the axle plate below to solve this, but discovered that it raised the robot off the ground quite a bit, something we wanted to avoid, and it was very flimsy since it was so far away from the frame. We discussed these issues with our coach and brainstormed various methods we could use to attach the axle the frame in a more secure way; he suggested that we use a pillow block design that would have one side of the axel touching the frame. That way we would save space, while also having a lower-lying robot. This design worked out beautifully, leading to the design we are currently using.

    The axles and wheels aren’t the only new thing about our robot: we're using motors with a gear ratio of 20 rather than 40s and 60s. This is another reason that we wanted to create such a minute robot. The gear ratio combined with the size will make this robot a speed demon on the field and allows us to dart between the minerals and the depositing location quickly.

    Next Steps

    In the upcoming weeks we will continue to tinker with this chassis design by adding a linear side and our gathering mechanism, and hopefully, we will be able to demonstrate it at the scrimmage next week.

    Intake Update

    Intake Update By Ethan, Abhi, Justin, and Kenna

    Task: Update the intake for the new robot size

    So, we created the corn-cob intake a few weeks ago. Unfortunately, it was a little too big for the Minichassis, so we had to downsize. Thus comes Intake Two. Continuing our history of using kitchen materials to create robot parts, we attached two silicone oven mitts to a beater bar equipped with the Iron Reign signature REVolution system. Then, we attached a REV Core Hex Motor to the design, then added a 2:1 gear ratio to increase the speed, as the motor wasn't exactly what we wanted.

    Then, we attached our new passive sorting system. Instead of being the old, bulky sorting system, the new system is just three side-by-side bars spaces 68mm apart with tilted wings to move blocks upwards. The 68mm number is important - the size of a gold block. This allows the balls to be struck and fly upwards into the intake while sliding the blocks through the system.

    Next Steps

    We need to attach this to the robot to test intake. The most likely way this'll be done is through a pivot over the walls of the crater from the top of the robot.

    Strategy and Business Whitepaper

    Strategy and Business Whitepaper By Ethan

    Task: Write the Strategy+Business Whitepaper for the Journal

    For teams who don't know, this kind of paper is suggested for judging. Iron Reign usually completes one every year. You can download the pdf of this post here.

    Intro

    This year is Iron Reign’s eleventh season in FIRST, our ninth year overall. We’ve participated in five years of FLL and seven years of FTC:



    FLL

    • Body Forward
    • Food Factor
    • Senior Solution
    • Nature’s Fury
    • World Class



    FTC

    • Ring It Up!
    • Block Party
    • Cascade Effect
    • RES-Q
    • Velocity Vortex
    • Relic Recovery
    • Rover Ruckus

     

    While our team originated at WB Travis Vanguard and Academy, as our members became older (such is the passage of time), we moved to the School of Science and Engineering at Townview (SEM) in DISD. Despite our school being 66% economically disadvantaged and being Title 1, our school consistently ranks in the top 10 nationwide academically. Our school also has numerous other award-winning extracurricular clubs; including CX Debate, Math/Science UIL, and more. Our school employs a rigorous STEM-based curriculum, which provides our students access to specialized class schedules, such as Engineering, Computer Science, and Math, as well as paying for AP classes that our students would normally not be able to afford. The average SEM student takes at least 10 APs.

     

    A History of Iron Reign

     

    Iron Reign has been a team for nine years. We initially started as a First Lego League (FLL) team, plateauing in regionals every year we competed. This was usually not due to the actual “robot game” in FLL, but because of our presentations. Starting there, Iron Reign was defined as focusing on creative and innovative designs. We also did Google’s Lunar X Prize program every summer, achieving finalist status in 2011 and 2012. Upon moving to high school, we started doing FTC, as FRC was too cost-prohibitive to be parent-run.

    We have been an FTC team for 7 years, advancing further and further each year. In Velocity Vortex, we got to the South Super Regionals, qualifying by winning the North Texas Inspire Award, which means that we represent all parts of the competition, from teamwork, to the presentation, to creativity, and to the actual game. In Georgia, the same year, we were the first alternative for Worlds if another team dropped out.

     

    Then, last year, we finally got to Worlds. We got there in two ways: the 2nd place Innovate award at Supers, and also got the lottery, on the prior merits of being a FIRST team for so long. There, we got the recognition that we’d been seeking – we won the Worlds Motivate Award.

    In the same vein, we compete in the Texas UIL State Championships. For those unfamiliar with UIL, it is the main organizational committee for all public school academic and athletic events in the state of Texas. Through UIL, we helped compete in the first test program for the UIL Robotics program and since then have competed in every subsequent tournament. This year, it finally got out of the trial period, and became a full-fledged competition.

     

    Outreach

     

    Our outreach stands out from other teams through our mode of presentation. Last year, we renovated a 90’s Seaview Skyline RV, took out the “home” components, such as the bathroom and bedroom, and turned it into a mobile tech lab, so that we can bring STEM to underprivileged demographics within our community. Our RV currently holds 4 3D Printers, 30+ computers, 3 widescreen TVs, and 1 microwave. Our current curriculum consists of teaching kids 3D modelling in the back of the RV, using Google Sketchup, as it is free and available to any family with a computer. We usually help them design keychains, as they are memorable, but don’t take excessive time to print on our printers. In the front, we teach kids how to use EV3 robots and teach them how to use the EV3 programming language to compete in a sumo-bot competition. We also give advice to parents and educators on how to start FIRST teams.

     

    To make Iron Reign’s history entirely clear, we built the RV two years ago. We do not claim any credit for the actual construction of the RV in this journal; however, we do share the goals of this program: making the RV run as a standalone program, expanding the program to other communities, and serving more and more underprivileged communities in Dallas. To our own standards, we have achieved this.

     

    Our current funding services for the operation of the RV come from Best Buy, who purchased the thirty-plus laptops and four 3D printers. We receive grants from non-profits such as BigThought and Dallas City of Learning to fund events and provide staff (even though our team provides staffing).

     

    This year, we have obtained $150k in additional funds to expand our outreach program by building a second Mobile Learning Lab. This is an unprecedented level of funding - it can cover the majority of buying an RV, staffing it, and filling it to the brim with technology. So far, this is the highlight of the Iron Reign season.

     

    When not in outreach service, we can transform our RV into tournament mode. We have taken numerous long-distance road trips aboard our RV, with locations such as Austin, Arkansas, Oklahoma, and Florida. We substitute the laptops for a band saw and drill press, use the flat screens to program instead of teach, and bring our higher-quality personal 3D printer. At tournaments, we encourage other teams to board our RV, not only to encourage them to start their own similar programs, but also to help them with mechanical and building issues.

    Iron Reign spends a lot of time on outreach. So far, we’ve spent 84.5 man-hours and talked to just under 2000 people (1995) within our community. Our goal of this outreach is to reach disadvantaged children who would not normally have the opportunity to participate in STEM programs in order to spark their interest in STEM for future learning. Some of our major outreach events this year include Love Field Turn Up!, where we reached 1100 children from around the Metroplex. We’ve worked for our school district in various circumstances, including bringing children back-to-school STEM education and running orientations for our high school.

    We also represent FIRST in a variety of ways. At our Mobile Learning Lab events, we talk to parents and educators about starting their own FLL and FTC teams. We currently mentor our school’s FRC team Robobusters and are in the process of founding another. We are the mentors for our sister team, FTC 3734 We also provide help as-requested for FLL teams to go back to our roots. As well, we’ve historically hosted underfunded teams for late-night-before-tournament workshops.

     

    Date

    Event

    People

    Hours

    # People

    2018-04-26

    SEM Orientation

    Shaggy

    6

    200

    2018-06-23

    Turn Up! Dallas Love Field

    Justin, Ethan, Charlotte, Kenna, Abhi, Evan

    24

    1100

    2018-07-14

    Dallas Public Library

    Ethan, Kenna, Charlotte, Evan

    16

    190

    2018-07-21

    MoonDay

    Karina, Ethan, Janavi, Charlotte

    26

    200

    2018-07-22

    Summer Chassis

    Kenna, Ethan, Charlotte, Karina, Shaggy, Abhi

    24

    25

    2018-08-01

    SEM Summer Camp

    Arjun

    6

    175

    2018-08-18

    Back to School Fair

    Ethan, Kenna

    6.5

    130

    2018-10-13

    SEM STEM Spark

    Ethan, Charlotte, Janavi, Abhi, Karina, Justin

    80

    140

    2018-10-16

    Travis High School Night

    Ethan, Evan, Kenna, Charlotte, Karina

    12.5

    120

         

    201

    2280

    Business and Funding

     

    Iron Reign, for the past two years, has increasingly ramped up its funding. We aggressively seek out new sponsors so that we can continue to keep Iron Reign great. Currently, these include:

    • BigThought - RV materials, staffing, and upkeep
    • Dallas City of Learning (DCOL) – RV materials and upkeep
    • Best Buy – 4x3D Printers, Laptops for RV
    • DISD STEM – Practice field and tournament funding
    • RoboRealm - $1500 of machine vision software
    • Dallas Makerspace – Access to machining tools
    • DPRG – Robot assistance
    • Mark Cuban - $2500
    • DEKA - Rookie team funding for our two new teams
    • Texas Workforce Commission - $525 for our team, $2350 for new ones



    We are always seeking more funding. We apply for the FIRST and FIRST in Texas grants every year, and seek grants from STEM-curious companies and individuals in the Dallas area. We have applied for grants from Orix and Mark Cuban, receiving personal funding from the latter. We receive staffing and upkeep from a local Dallas non-profit, BigThought. Currently, we are seeking funding and assistance from Ernst and Young, an international company with a Dallas branch, that a team member works for.

     

    In previous years, we have lacked the ability to get significant transportation funding to get to tournaments. However, through our partnership with DISD, we have solved that problem, and when DISD is unable to provide transportation due to short notice, we can provide our own transportation due to our building of the RV.

     

    Reference Business Letter

     

    “To whomever it may concern,

              My name is Abhijit Bhattaru, and I am currently a member of Iron Reign Robotics at the School of Science and Engineering at Townview, a DISD magnet school whose population is 66% economically disadvantaged. We have been a FIRST team for about nine years, over half of some of our members’ lives. For the past six years, we have operated as FTC Team 6832, Iron Reign. We’ve achieved various forms of success in these years, culminating with our rise to the Houston World Championship this year, winning the Motivate Award, an award for outstanding outreach within our community.

     

              What makes our team stand out from other teams is our dedication to our community. Two years ago, we converted a Sea View RV into a Mobile Learning Lab equipped with 4 3D printers, 15 EV3 robots, and 30 laptops to teach children basic programming and 3D modelling. The purpose of all of this is to start a spark of STEM in underserved communities so that these children can later go into STEM. And, we have expanded this program nationwide, presenting at the National Science Teachers’ Association national conference in 2017. We have partnered with local nonprofits such as Big Thought to fund our outreach expenses, and to reach out to interested communities across Dallas, and the nation, to expand our program.

     

              So, why do we need your help? Our school is 66% economically disadvantaged, and adding to that, DISD is facing up to an $81 million budget gap. The district’s funding for robotics has been dropping to the point where only the basics are covered and even then come too late in the season due to red-tape. The one silver lining is that the DISD STEM Department is still able to handle most of our competition travel expenses. This offsets our largest expense category. But we still have to fund the development of our robot, and we aim high. Our robot earned an Innovation Award at the twelve-state South Super Regional Championship this year. We try to push the boundaries of design and execution and this requires a different level of funding for parts, materials and tools.

     

            To achieve this higher level of funding, Iron Reign is aiming to create a 501(c)(3) foundation to avoid the level of red tape and financial mismanagement from DISD that we have experienced for the past several years. This is where you come in, Mr. Cuban. We are asking for a seed donation for this non-profit, so that our team can become a free-standing team unhampered by DISD’s bureaucracy. Our mission would still be to serve our school and community, as it has been for the past eight years, but we would be able to avoid DISD’s mismanagement.

     

            If the money is not utilized for a seed donation, we would allocate it for new robot parts and equipment. A starter kit for FTC is at least $600 but this is nowhere close to cost of a World Championship robot. To become more successful in the robot game for the following seasons, we would need a higher investment into parts, considering many things can go wrong in an 8 month season. Your donation to the cause would allow us to become more successful.

     

            In return for your investment, Iron Reign will set out to accomplish what you desire from us. We can promote you and your companies on our website, presentations, etc. However, this is just one option. We are open to helping you in whatever way you  would like in return for your help to our team.

     

               Thank you for taking the time to consider our request, and if you happen to have additional time, we would like you to look over our previous Engineering Journals here to see our team’s engineering process and history. To see a video about our robot, please visit https://www.youtube.com/watch?v=TBlGXSf_-8A.

     

            Also, since you were not able to meet with us, we thought we would bring ourselves to you. Here is a video of our team and the FIRST Tech Challenge program.

    Thanks for your consideration,

    Iron Reign (6832)

    Looking Back, Moving Forward

     

    Recently, Iron Reign has put a large emphasis on recruitment. We have alternating years with high turnover due to graduation, so we hold recruitment meetings at our school every year for both Iron Reign and Imperial Robotics.

     

    We already have another team in our school, team 3734 Imperial Robotics. 3734 is an entirely different team, with different sponsors, members, robots, journal, outreach, and codebase. That being said, we recruit the more accomplished members of that team. The teams’ relationship is most similar to the difference between a Junior Varsity team and a Varsity team.

     

    We tend to recruit based on robotics experience, but having robotics experience alone is not a guarantee of joining our team. Iron Reign has a specific culture, and we tend to recruit people whose personalities fit our culture. We also do not accept people who only want to join robotics as a resume booster. While robotics is indeed a resume booster, and we allow every member to claim co-captain on their college applications, members of Iron Reign ought to join out of their genuine passion for robotics, not because of it getting them ahead in the rat race of college applications.

     

    This year has been an unprecedented year in recruitment for Iron Reign. We recruited approximately 30 new freshmen, expanding the Iron Reign program from two teams to four; from Iron Reign and Imperial Robotics, to adding Iron Star Robotics and Iron Core. And, our efforts have been recognized by our donors: we have been supplied four additional REV kits, and two fields so that we can support the larger program.

     

    Build

     

    Iron Reign utilizes a variety of parts and kits. At the moment, Iron Reign prefers the REV kit due to its simplicity - everything seems to just fit together, while still being minimalist. However, Iron Reign’s old standby is 3D printing. We’ve used 3D printing before it became widespread within FTC, and we’ve become sort of pros at specialized design. We even have our own 3D-print kits such as REVolution, a system to turn REV extrusions into axles.

     

    This year, we’re using a new base that’s more adapted to the challenge. Its working name is Minichassis. It is approximately 6”x6” for the base with an additional 4” extension for mounting. It uses four 4” AndyMark mecanum mounted low to the ground with NeverRest 20s with planetary gearboxes attached to each wheel. So, the robot is astoundingly small and fast.

     

    We have two main attachments to our robot, the lift and the intake. First, the intake is a small square with silicone oven mitts attached to it. It knocks the particles upward into racks spaced 68mm apart. This spacing allows the blocks to fall through while the balls move upwards into the lift. Then, the lift. The lift is a series of REV rails attached through a linear slide kit with a hook and particle holder on the end. This extends, allowing the robot to deposit particles in the lander while also being able to hook onto the lander.

     

    In addition to this design, we have also developed BigWheel, aptly named for its 6-inch wheels at the back with a front-facing omniwheel. At the front of the robot, we installed two “arms” which brace an intake system named “CornCob” for its lumpy, cylindrical appearance. This is mounted at a height just so it only contacts the silver particles, not the gold. But, what truly differentiates this robot is it’s lift mechanism. Unlike the majority of FTC robots we’ve encountered this year, BigWheel has no lift, extending-arm, or linear slide. Instead, we have a central lever mounted to two high-torque motors, with a ridiculous 3:1 gear ratio for a cumulative 19.4 N*m of torque. This serves to rotate the robot into a near-total-vertical position, allowing the arms of the robot to reach to the lip of the lander. We feel that this differentiates our team’s robot from the majority of other robots within the current FTC season.

     

    Code

     

    Iron Reign has a large pre-existing codebase. We’ve been improving off of our prior code for years. The particulars we want to focus on are thus:

    • Pose
      • This class uses the IMU to approximate the location of the robot on the field relative to the starting position. The math behind this is simple; we use trigonometry to calculate the short-line distance between the robot’s prior location and its current one.
    • OpenCV
      • We use OpenCV to recognize particles in autonomous. To do this, we trained the software to differentiate between gold and silver particles. To extend our knowledge of computer vision, we ran tests of OpenCV vs TensorFlow CNN in Python to see if there would be a meaningful runtime difference.
    • PID
      • At this point, PID is common among FTC teams. However, as we moved to a new driving base for the first time in three years, we had to retune it, so we rewrote our code to account for the changes in behavior.

     

    Design Process

     

    Iron Reign uses two design processes in conjunction with each other to create efficient and reliable parts. First, we use the Kaizen design process, also used in industrial corporations such as Toyota. The philosophy behind Kaizen is the idea of continual improvement, that there is always some modification to each system on our robot that will make it more efficient or more reliable. As well, design competitions are a focal point of Iron Reign’s design process. In these design competitions, team members choose their favored designs that all complete some field challenge, and build them individually. Upon completion of each mechanism, the designs are tested against each other, considering weight, maneuverability, reliability, and efficiency.

     

    This year, we have exemplified this process. Since kickoff, we’ve had two separate design paths, allowing us to explore the most efficient and workable design. Here, we will describe each segment in detail.

     

    First, we explored chassis designs. Over the summer, we created BigWheel, the aforementioned paragon of uniqueness - operating off of just two wheels. Then, we created the MiniChassis to compete against it, letting the best robot win. As of now, this is undecided, but we’re entering BigWheel to compete, as we feel that this is our more technically-impressive robot through its ability to rotate into a vertical position.

     

    Then, we compared intake mechanisms. First, we created the Corn-Cob intake - a silicone ice cube tray - and mounted it on a beater bar that would ensure sorting through the height difference between blocks and balls. We found that if we mounted it at about 6.5 cm above the ground, it would only consume the silver particles. After, we felt that this wasn’t our best work. So, we created a second intake. As described previously, we attached silicone oven mitts to a beater bar, and added lower fins as a ramp separated 68mm apart so that blocks would fly through, even as balls entered the intake system.

     

    The best thing about Kaizen is that we can mix-and-match these systems for the ultimate robot. At the moment, we’re considering removing the second intake from MiniChassis so that we can replace the Corn-Cob. The fact that we can even consider this system matching casually demonstrates the power of the Kaizen system.

     

    BigWheel Arm

    BigWheel Arm By Evan

    Task: Design an arm for BigWheel

    Bigwheel’s arm is going tied with the lifter arm as the most integral part of the robot. It wouldn’t work without it. Since our scrimmage, we have learned how to make this arm much more efficient, starting with some supports. The arm was made of two disconnected Tetrix rails scavenged from the bottom of our scrap bin, lending itself to weakness and instability, much like a country that recently won its independence. The worst part was how the two sides of the arm would be out of sync with one another, creating a twist in the arm that caused it to drive in an odd path. Since then it has been stabilized with cross beam REV rails that have significantly straightened out the robot. Why we hadn’t done it before is a mystery to me, and something we should have recognized as an issue sooner, but hindsight is 20/20 and since we can’t change the past we can only vow never to make the mistake again. Always support your attachments. The next upgrade on the arm is going to be the box to hold the minerals. Right now it’s made of cardboard off an amazon box, and it kind of sucks. I can say this because I cut it out and made it. The plan is to make it out of polycarb but we only came to this conclusion after a bit of debate. The reason polycarb was not our immediate solution is because it’s unfortunately quite heavy, and instead the first thing we came to think of was thin plywood and duct tape. Thin slices of plywood would be taped together to create a fabric like box that still had form. This idea still lent itself to breakage, and we next went to a design using a thin plastic sheet, the same kind of plastic that is used inside milk cartons. The only issue is that it’s super weak and doesn’t form well, so we would have to build a frame for it, much like the plywood and tape. Finally we came to the polycarb and decided upon that. So far it works as a nice way to hold the blocks as we transport them into the lander.

    Next Steps

    Right now we’re toying around with the idea of an arm that not only flips out but also extends using a gear and tooth track made from Tetrix parts of days gone by. The reason for this is to gain a little extra height that we were lacking before in the robot and a little more flexibility when we grab minerals from the crater. To do this I had to take apart the arm from our first ever FTC robot, and use the toothed track and gear plus the extra long tetrix bars to create the slides. So far the slides are surprisingly smooth and we have high hopes for the future of the arm.

    Torque

    Torque By Karina

    Task: Calculate the torque needed to lift chassis

    After seeing how well the robots that could latch onto the lander performed at the scrimmage, Iron Reign knew that we had to be able to score these points. We originally tried lifting with a linear slide system on MiniMech, but it was not strong or sturdy enough for the small chassis, and would definitely not be a functional system on BigWheel in time for competition. And so we thought why not use this opportunity to *flex* on the other teams with an alternative design? An idea was born.

    We decided we would latch onto the lander using the same arm used for intake, and then pivot the main body of BigWheel up off of the ground about an "elbow joint", much like how humans do bicep curls. To do so, our motors would need to have enough torque to be able to lift the loaded chassis off the ground once the arm hooked onto the latch. First, we measured the mass of BigWheel. Then we found where the center of mass was located. The distance from the pivot point to the center of mass became our lever arm, also known as the radius.

    Calculating torque required knowing the forces acting on BigWheel at its center of mass. In this case, there was only the force due to gravity (F = mg). Before we could plug BigWheel's mass into the equation, we converted to units of kilograms (kg), and then used the value to find the newtons of force that would oppose the upward motion:

    Finally, we plugged the force and radius into the torque equation:

    Next Steps

    The next step is to test which gear train will output this torque value based on the motors used and the gear ratio.

    Lift

    Lift By Janavi

    Task: Design a lift for MiniChassis

    So we need to lift the robot. There are multiple ways to accomplish this including a linear slide or an arm; we decided to begin experimenting with the linear slide method. I created a linear slide using Tetrix bars and the standard linear slide kit. Instead of putting nuts with bolts on the end as stops I took an aluminum plate with holes on it and had Max, one of our mentors, assist me by cutting the plate into small squares to screw into the end of the bar. We planned to test out the tetrix bar at the scrimmage we attended, but two things went wrong. First, I forgot to make the linear slide stronger by attaching side plates, and we only brought 3 of the four needed REV hubs to be able to use both our MiniChassis and our big wheel chassis. Since BigWheel required more testing, we decided to give up one of our two REV hubs so that BigWheel would be able to get some much-needed testing. Since we were not running mini chassis I attempted to strengthen to linear slide by adding side plates but was unsucessful due to a lack of parts availiable. We relized that if we were to include a linear slide on our robot it would require too much maintaince and would soon become too finicky.

    Next Steps

    In the end we decided to scrap the standard linear slide in place of a geared linear slide with a different bar. By usingthe geared slide we would eliminate the need to deal with complicated string and would need to simply reverse the difrection of the motor to move it up and down. Working with the previous linear slide though showed us that it was not the best implementation to use with our robot design and allowed us to try better more efficient variations.

    BigWheel Upgrades

    BigWheel Upgrades By Evan

    Task: Get BigWheel ready for the tournament

    Sunday and Monday were good days to be an intake system for big wheel. Mounts were built to attach both types of intake to the rack and pinion tetrix slide and a new way of mounting the arm to the chassis. The original corn on the cob intake was sized down for the system, and stitched to a REV rail design as opposed to the tetrix and REV rail hybrid it was before. It has yet to be chained up but that should happen soon. The idea is that since it’s attached to the rack and pinion track, it reaches high enough for the robot to put the minerals in the lander. The only issue is that it that we have yet to find an ideal gear ratio for the arm, but we imagine that what we have now will suffice (a small 12 tooth gear to a large 86 tooth gear for that extra torque). We have to work on the actual mount that the arm will attach to, the only issue being space and that there may not be enough of it without either switching to bevel gears or chaining the motors to the small 12 tooth gears. We have yet to decide exactly what we’ll do, but since we may not have the bevel gears we want, it might end up being a chained mechanism. Another addition that is simple enough but quite necessary, is a tail for the robot to be able to stop itself from flipping backwards, something that is a very real danger of the design. It will probably be made of polycarb with aluminum or steel support on either side, just incase the polycarb is not enough to support the push of the robot. Part of this process will involve some code tuning so that the robot stops itself, but the tail is necessary as a preventative measure.

    Next Steps

    There’s still a lot of stuff we will have to do to prepare the robot physically for the competition this saturday, but I believe it will get done.

    Materials Testing Planning

    Materials Testing Planning By Ethan

    Task: Design a lab to test nylon properties

    So, Iron Reign is used to using off-the-shelf materials on our robot: silicone oven gloves, ice cube trays, nylon 3D-printed parts, and more. But, we've never actually done a thorough investigation on the durability and efficacy of these parts. Because of this, we've had some high-profile failures: our silicone blocks breaking on contact with beacons in RES-Q, our nylon sprockets wearing down in Relic Recovery, our gears grinding down in Rover Ruckus. We're a little sick of it. So, we're going to do an investigation of various materials to find their real properties.

    Nylon Testing

    A majority of the 3D-printed parts on BigWheel are nylon - we find it to be stronger than any other material save ABS, but much less prone to shattering. Still, we still deal with a substaintial amount of wear, and we want to find the conditions under which damage happens.

    So, to start, we are printing a 4.5" x 1.5" block with a thickness of 4mm with an infill of 60% out of nylon. We chose these values as our average part is about 4mm thick, and our high-strength nylon pieces are about 60% infill. Then, we are going to test it under a variety on conditions meant to simulate stressful operation. As well, we're going to measure other values such as coefficient of friction using angle calculations.

    Silicone Testing

    Similarily, we use the silicone oven mitts on our intake; we find that they grip the particles pretty well. The main thing that we want to test is the amount of energy they have while rotating and then the amount of energy they lose upon collision. We plan to test this through videoanalysis. In addition, we wish to test the coefficient of friction of the mitts to see if a better material can be found.

    Next Steps

    We are going to perform these labs so that we can compare the constants we recieve to commonly accepted constants to test our accuracy.

    Chassis Mark Two Planning

    Chassis Mark Two Planning By Ethan

    Task: Plan a new BigWheel chassis

    Our next tournament is a while away, in about two months. So, we have a little bit of time to redesign. And, our current chassis has plenty of faults.

    Our original BigWheel base.

    First and foremost, our chassis was built for a testing competition, not to be a full fledged competition robot. As such, it's a little lacking in features that would be normal on such a robot such as mounting points for other components, durability, and free space. So, we need a redesign.

    We're starting from the ground up; our current base is a square metal frame with a polycarb bottom. While this is a good start, it has some issues: the base seems to be a little wobbly due to the polycarb, there's only one level of construction, so our motor mounts, REV hubs, and supports compete for space, and we have to add all the counting points ourselves. This being Iron Reign, the logical solution to this is maximalism.

    The main way to prevent the wobbliness is by replacing the polycarb with something a bit sturdier, as well as not having everything simply bolted together. Thus, we're going to dive headfirst into the next step - welding. We plan to cut a base out of aluminium as well as four side plates to create a dish-like shape. Then, we plan to TIG weld these plates together (TIG welding uses a tungsten electrode in contact with two seperate metal plates in combination with a filler metal that melts and joins the two plates together).

    Basic design for the newest version of BigWheel.

    Next Steps

    We plan to cut the aluminium next week, and TIG weld the pieces together the week after that. We're beginning to train a few of our members on TIG welding and we already have some of the safety equipment to do so.

    Friction Coefficient and Energy

    Friction Coefficient and Energy By Ethan

    Task: Measure the coeffiencent of friction of our oven mitt intake

    So, we wanted to measure various constants of materials on our robot. Earlier this season, we found that a nylon-mitt collision on our intake sapped the rotational energy of our intake. But, that was just a build error, easily fixable. But now, we plan to measure the energy lost from particle-mitt collisions, and the first part of this is to find the coeffiencent of friction of the silicone mitts.

    To measure the coeffiencent of friction, we first had to simplify an equation to determine what values to measure.

    From these calculations, we determined that the only factor to measure to determine the coefficient of friction between blocks and the mitts is the angle of incline. Therefore, we created a simple device to measure the angle at which slippage begins to occur.

    The angle was about 27 degrees, so the coefficient of friction is equal to arctan(27)=0.44. This is a pretty good coefficient of friction, meaning that the intake is very effiecent in bringing the particles in, but it also means that the intake loses more energy on collision.

    Next Steps

    We need to measure further constants such as stretch and wear of nylon. To do so, we're printing a simple testing nylon block.

    Nylon Strength Test

    Nylon Strength Test By Ethan

    Task: Determine what circumstances wear down nylon

    We've had some issues with our nylon sprockets, mainly through excessive wear and tear. So, we want to test what circumstances cause what deformation.

    Linear Deformation

    This one was simple. We printed this block with 60% infill (the highest infill we tend to use), measured its length (3.75") and hung one end from our deck. On the other end, we inserted a bar and had a member (182 lbs) hang on it, then we measured its new length (3.8"). Thus, the constant of deformation is [weight]/[change in length] = 650 kg/cm. This demonstrates that linear transformation isn't Iron Reign's issue, as the highest possible weight put on any nylon piece on our robot is ~27 lbs/12.25kg.

    However, there is other damage. After testing, we found internal damage in the nylon from where it was hanging.

    Next Steps

    Next, we need to test the rotational damage that nylon incurs through friction. We plan to design a simple rotational sprocket and run it on a motor for a set amount of time and measure the wear to determine wear per unit time.

    Programming breaks Build

    Programming breaks Build By Abhi

    Task: See how we broke the robot

    After a lot of use, it finally happened. The robot arm broke.

    When testing, we always heard the gears grinding some times and we thought it wasn't an issue. There were instances like once when we accidentally made the robot stand up under a table. When Evan took off the linear slides for maintenance we saw this happen. Other times, the robot would press the arm down into the foam and keep pushing when it couldn't really keep going, leading to grinding.

    Not only did the arm break but also the Superman mechanism. This broke mainly because we didn't set proper ranges of motion of the arm and the gears would grind when there was interference. Because of the damage, we can't use the existing gears.

    Next Steps

    We hope to gang up the gears and make the mesh stronger to fix the build side of things. In the code, I already added the software limits to motion so we don't have those problems anymore.

    Arm Repairs

    Arm Repairs By Evan and Abhi

    Task: Fix elbow and Superman

    In a previous post I explain how our elbow and superman arms broke. We made some hustles and got them fixed. We reinforced Superman by ganging up multiple gears (as seen above) and repeated a similar process with the elbow arms. Hopefully this will make BigWheel more secure, especially with software limits in the code.

    Nylon Materials Testing 2 - Wear and Tear

    Nylon Materials Testing 2 - Wear and Tear By Ethan

    Task: Test the amount of wear on a moving nylon part over time

    So, here's the next article in the material testing series. After our last tournament, we noticed several 3D-printed sprockets that had worn down significantly. So, we wanted to meaure how much wear one of our nylon sprockets takes per second.

    First, we printed out a model of one of the REV sprockets, using the STEP file here. We printed it with ~45% infill, our average for sprockets and other parts. Then, we attached a REV Core motor to an extrusion, then mounted the nylon sprocket on the other side. Then, we measured the length on one of the teeth. We ran the motor for 1:05:45, and then measured the length afterwards.

    So, the tooth length before was 5.3mm, and after, it was 5.23mm, for a difference of 0.07mm. Then, we ran the system for 1:05:45. This results in a wear rate of 1.77*10^5 mm/sec. So, given that we use our robot for about an hour, cumulatively, in a tournament, 0.0638mm, or 1.2% of the sprocket. This is enough to be noticeable and indicates that we should keep extra sprockets at tournaments so that we can do a quick replacement if needed.

    Next Steps

    We plan to perform more materials testing in the future; in particular, we'd like to determine the wear rate of the regular REV sprockets as well, but this requires a more rigorous expiriment.

    TIG Welding Plans

    TIG Welding Plans By Evan

    Task: Detail TIG welding plans and why they failed

    At the beginning of the season, we saw that our robot base was not as well crafted as we originally thought it to be. While we have worked to correct it over the season, it’s still not perfect, and we came up with the idea of making the frame from light aluminum instead of the polycarb, and to hold it all together with TIG welds. While a fun idea at the time, and with a new TIG welder being shipped to us, it sounded like it was a definite thing we were going to do. Problem is, there were many other problems on the robot more important than a new base. So we pushed the TIG plan to the side, in lieu of correcting other issues like the lift and the intake. While we won’t completely throw the idea out, it will be a while before we begin to start the project. Also hindering us is the amperage output of the home, which is too low to run the TIG welder off of. Until we get additional amperage to the house, our plans will be on hold but not forgotten.

    BigWheel Arm Locks

    BigWheel Arm Locks By Evan

    Task: Create locks to keep BigWheel's intake arms in an extended position

    So, as y'all know, an important part of this year's challenge is scoring minerals in the lander. Additionally, our upright elbow cannot raise the scoring mechanism to the lip of the lander alone. Thus, we had to create a way to get those additional inches to score.

    First, we tried a REV linear slide design. This worked, but barely. It repeatedly got stuck, at one point even needing to be sawed apart at a tournament due to its inoperability. So, we switched to a new brand of linear slides, the MGN12H with 12mm steel rails. But, since we were no longer using REV, we needed a new design to keep the arms in the extended position.

    The new design relies on gravity. When the robot is on the lander in the hanging position, it will stay within the (18^3)" sizing cube. However, as it descends, the linear slides will glide upward, staying attached to the lander until the robot contacts the mat. And, as the slide finishes moving, it will move over a triangular piece of polycarb such that it is easy for the slide to move up, but near impossible to reverse its direction. This will ensure that the robot's arm stays extended.

    Next Steps

    We need to reattach the mounting point for hanging in order for this system to work.

    Scoring Mechanism

    Scoring Mechanism By Janavi and Abhi

    Task: Create a way to hold minerals

    We now have a lift and an intake system, but we're missing a way to actually hold onto and deposit the minerals once they have been gathered. To achieve this, we created a prototype.

    We want to create a box-like shape that can be attached to a moving axle to hold the minerals when lowered. When the lift is up in the air, the axle can rotate to lower the box and let the minerals fall into the depot. We tested out multiple designs including a literal box design. We ended up having to nix that as there was no way to get the minerals out of the box once they were in.

    Our second design was a sloped shape: just steep enough to hold onto the balls but not so steep that the balls couldn’t escape. To create this shape, we decided to have a rectangle attached to an axle able to hold the minerals when down and deposit the minerals when spun. We created multiple variations with different sizes as can be seen in the drawing below. We eventually settled on was design B, a square that was 155 cm by 155 cm.

    We decided to not use design A as it was simply too large and continuously hit against the edge of the rail. We progressed to a smaller size of 155 mm by 155 mm (design B) that worked well. We attempted another design of two separate backs as two separate channels for the minerals (Design C). However, we decided this wasn't a very good design because there was an increased chance of the ball getting stuck in between the channels, causing either a penalty or a decrease in the number of balls we can control.

    After creating the back of our holder, we realized that we needed to elevate it off the back of the rails at an angle. It was the only way to hold the balls and allow them to come down a ramp when the axle is spun. We decided that the best way to achieve this was through two wing-like triangles on the side that we could bend to ensure the minerals couldn’t escape out the side. We went through multiple designs as can be seen below

    At first, we attempted to attach two right angle triangles with 155mm acting as a leg of the triangle. We varied this design by increasing the angle of the slope so that the balls would be held at an angle that allows them to not slip. But, after creating this design out of cardboard and attaching it to the axle, we saw that the sharp angle interfered with the beater bar. To amend this, we changed the triangle attached to the end of the rectangle to have the 155 mm side be the hypotenuse of the triangle. Again, we varied the design in the steepness of the triangle. Through this, we determined that a slope of around 30 degrees was the best design.

    After finalizing our design, creating it out of cardboard, and attaching it to our robot, we cut the piece out of polycarb. We bent the side triangle using heat and drilled in the holes to attach the axle with.

    Next Steps

    Although this design works well, we want to continue to change and improve upon it. For example, the next way we can improve the design is by changing the way that the polycarb is attached to the axle through a 3-D printed part.

    Creating Side-Latches

    Creating Side-Latches By Evan

    Task: Allow the robot's arms to stand on their own

    My second favorite building material has to be polycarbonate. It can be both flexible and sturdy, malleable and stiff, and everything in between. Recently, it’s become the material of choice in the different aspects of out lift. The issue with the lift is that many of the pieces needed to be made required a bit of a specificity that’s hard to obtain using aluminum parts, so I turned to good old polycarb. Over the past four years, I’ve been developing my polycarb bending skills, that is, the perfect technique for quickly and precisely bending polycarb into the shape you need it, with as little air pockets as possible. The key is a small butane torch, similar to the kind you use to make crème brûlée, held at just the right distance, with a steady hand and a good pair of eyes. Run the torch back and forth across the part where you want to bend, in the pattern of the bend you’re trying to achieve, watching closely for the first air pocket. Once you’ve spotted it, bend it. For tight, right angle bends, press the piece of polycarb against a hard surface until the right angle is achieved. If there’s an issue in your bend, simply heat it up again. This, however, weakens the piece so try not to do it on pieces that need to bare a load. I had to bend a complex piece, and while, it doesn’t look super complex in the picture, it had very precise requirements so that everything could slide together in unison. The part I made went in between the two linear slides on the arms to the 3d printed latch we created, and worked very smoothly. While polycarb is not the best at retaining strength over distance, it’s worked well in this instance, and I couldn’t be more happy with it. The next stage or design for this will be to make these brackets out of steel, a job that will be made significantly easier once it warms up a little bit, stops raining, and we find the time to fire up the forge. I will forge a new, stronger version, which will hopefully eliminate a potential point of failure in our current robot. This is the plan. It will happen in due time.

    Modeling Slide Barriers

    Modeling Slide Barriers By Kenna

    Task: Create barriers to prevent the linear slide from falling

    Recently, we added polycarb barriers to our linear slide system. They were created as a temporary measure by bending the polycarb with a blow torch and are less exact than we would like. I am not personally one of our common modelers. We use PTC Creo Parametric, and I only have experience with SolidWorks. However, CAD is CAD is CAD; the basic idea is the same all around. Even as a senior, there's still opportunities to learn new skills as part of Iron Reign.

    My first lesson was that I create models in a really janky way. This came up during my internship where I was tasked with modeling a manufacturing aid, and my coworkers couldn't understand how the model was even functional. My personal brand of modeling generally turns out okay on SolidWorks, but not so much on Creo Parametric. I originally tried to overlap 3 rectangles, and Creo didn't register it as an enclosed shape and wouldn't extrude. When I was following internet tutorials to teach myself CAD, I missed some features that most know about. For any self-taught modelers out there, constructed lines are your friend. If, like me, you got bored of the tutorials and started messing around on your own to learn, you might have missed them. Especially for any geometric shapes you want to extrude, constructed lines in sketch mode make it much easier. They ensure that everything is perpendicular, but also that your shape will still enclose so you can extrude it. Armed with constructed lines, I finished our models (with some help from Abhi, one of our more experienced modelers). Our models printed in roughly 30 minutes using nylon on a Taz printer.

    Now, I can proudly say that I can model with Creo Parametric (if necessary). However, I'm excited to get more experience with it as the season progresses. Apart from blog posts, I tend to stay on the physical, and not digital, side of the team. It was fun to cross that imaginary boundary to help out with build. I'm glad that even as someone who only has a couple months left as an FTC member, I can still try and learn new things.

    Next Steps

    Though nylon has its many uses, it's still not as strong as polycarb. We're looking into whether or not the printed version will withstand the slide system. Perhaps, we may need to pursue a different material or a more exact method of creating polycarb barriers. Any posts continuing this thread will be linked here.

    Latch Model

    Latch Model By Abhi and Justin

    Task: Model and print the Latch

    Very early in the season, we made a hook, Although it was durable, it required a higher amount of prescision than we would have liked to have, especially in the rushed last seconds of the endgame. As a result, we designed a latch that is completely 3D printed and placed it on the robot.

    This is the general model of it fit together (excluding left panel). The panels in the front are there to guide the latch into place when extending upwards from the ground.

    This wheel represents what actually does the latching. When sliding upwards, there are two wheels that twirl in opposite directions and slot into the lander bracket. We attached a smaller piece to this to tension with a rubber band allowing us to move up into the bracket but not back down.

    Next Steps

    We actually mounted this onto the robot and it seems to hold its own weight. However, the mounting was done very weirdly so we need to find a definite place for this system before we use it in auto or end game.

    Belt Drive

    Belt Drive By Evan and Karina

    Task: Install a belt lift on our robot for depositing

    The most recent addition to BigWheel has been the addition of a belt drive lift on either side of the linear slides. We chose a belt lift over a string and pulley lift because while it may be more difficult to build and design for, it is also a much more secure, closed system, and doesn’t require stringing. Ever since last years’ linear slides, we’ve developed a hatred of string. It only creates problems. It comes off, it can snap, it’s a real pain to tension and tie even with the assistance of rubber bands, and rigging it to pull both ways takes forever. For these reasons, we switched to belt drive. While more complicated to build, it requires no spool, only tension, no knots, and is super smooth in its motion. Working on it has pushed it to my number two favorite way to translate rotational movement to linear movement, right behind rack and pinion, which will always hold a special place in my heart. Our current design relies on the same time of belt drive used on 3D printers, something that we as a team are familiar with. The issues that come with using a belt drive lift include a more complicated setup and a more difficult time to repair in the pit, a lower ability to bear weight due to slippage of the teeth, and a not so fun tensioning method that we recently discovered we can do with zip ties. Before we figured it out, we had been tensioning the belt with two small pieces of polycarb used to squish the two ends together but realized how overcomplicated we had made the process, and discovered zip ties worked just as well.

    Next Steps

    So far the belt drive has experienced a bit of slippage, but with the intake redesign we are just about to start on, it should have a better time lifting the intake. Overall, it’s something that I’ve learned a lot about, and I was overjoyed to have a new building experience.

    Designing Side Shields

    Designing Side Shields By Ethan

    Task: Create side shields for BigWheel

    Our tournament is on Saturday, and in traditional Iron Reign fashion, we're designing our side shields the Monday before. Iron Reign has access to an Epilog Mini laser-cutter through our school, so we had the genius idea to use it for the first time.

    We created our original design in Illustrator. The canvas size was 12"x18", ensuring that our design stayed within the size limits. Then, we found the side height of our robot's wheel hubs (1.3") for later use. The original design, above, was inspired by 1960s teardrop campers.

    The Epilog Mini is a CO2 laser cutter, which means that it can cut acrylic, cardboard, and wood. We don't keep our robot at school, which meant that we had to make a test cut at school. We had a variety of issues, our first print cut way too small, about 8.5"x11" when it should've been 17"x8". Our next cut caught on fire, burning in the machine as I tried to put it out without water. Our final test was successful, producing the cutout below.

    But, when fitted to the robot, issues became apparent. It was barely scraping the size limit, and while it fit over the wheel mounts, it failed to match the shape of the wheel. And, the shield grazed the ground, meaning that any rotation from the Superman arm would damage it or the arm. So, we created a second, smaller design.

    Next Steps

    We aim to cut these shields out of wood Wednesday morning after cutting the cardboard test print.

    Selective Intake

    Selective Intake By Evan

    Task: Design a new sorting mechanism for gold and silver particles

    The differentiation between the different shapes of minerals has been something we’ve been thinking about since day one. At the time I had a design for a box that allowed us to sort out blocks and balls by size, and only until now have I been able to find a way to implement it. Our original selective intake only accepted balls so we only have to go to the one loading area, but our new design allows us to, if we’re positioned right, deliver both blocks and balls to their respected containers. The reason it wasn’t implemented much earlier in the season is because the robot just wasn’t tall enough. We got it to reasonable heights, enough to score, but just barely. Now with our beautiful new belt drive, It’s possible to do.

    I was extremely excited to build it since it will make our drivers have an extremely easy time sorting minerals and decrease the stress they’re under by a huge fraction, hopefully increasing the quickness of delivery. If the robot has to barely move between intake and delivery, we will have done our job right. The selective intake also has a door built into it, which holds back the minerals until we’re ready to deposit. Gravity does the rest of the work, letting the balls ride out of a hole in the side into their depot, and letting the cubes go into their side unhindered. The other thing that we wanted to do was to have this process be almost completely mechanical, taking more stress off the drivers. The gate is released when a lever is pushed in and translated to a quicker motion with a pair of gears at a 2:1 ratio allowing for an easy deposit, and a self-contained, sleek look that I personally like a lot. The frame of the intake is made out of polycarb, bent with the sheet bender and cut into the correct form with the bandsaw. The whole thing is quite simple when you look at it from afar, but once you get closer you can see the intricacies that went into its design.

    The intake also heralds the return of the ice cube tray intake we had played around with at the beginning of the season, something I personally like very much. It’s got great compliance and with its new 3D-printed supports (Ninjaflex, 20% infill), I suspect it will make an incredible method of intake. This time, instead of stapling the thing together, we are sewing it shut, which should hopefully negate any problems the previous version had, mainly the one where it would come apart where the two sides met. The intake will be offset a little from the ice tray intake to allow for as much grabbing action as possible.

    Next Steps

    I hope to have the whole thing on the robot in a few days time, allowing the drive team as much time to practice with it as possible, since that’s the biggest thing we have lacked up until now.

    Pool Noodle Intake

    Pool Noodle Intake By Evan

    Task: Design a quick intake for the robot before competition

    The night before our final qualifier, we decided that the intake system on the robot was not up to our standards. To fix this issue, we poked some holes in a pool noodle, and put surgical tubing through it. While this was a quick and semi effective fix, it did have some problems, mostly due to the rushed nature of its construction. The tubing slid back and forth, and the noodle itself was slightly offset from the depositing box, causing it to be a little off. It could only be remedied by taping all the surgical tubing together, allowing it to grip the minerals better and allow for a smoother intake. The other big issue with this version of the intake was that the depositing mechanism was super finicky and required very accurate driver control and a little bit of luck. Right after we got back from the qualifier, I took it upon myself to smite the thing, and replace it with the current intake system, a reimagined version of the corn on the cob intake system.

    Next Steps

    This isn't a permanent solution, but we need to have something simple so that we can intake the gold and silver particles at the tournament. We plan to replace this with the actual corn on the cob intake after the competition.

    Latch Updates

    Latch Updates By Justin, Abhi, and Ben

    Task: Update the latch

    We were faced with the problem of not having a working latch. Our first attempt was made out flat metal brackets, but they slid off under any stress. Our next step was to come up with a latch that would allow the driver to easily latch on, and support the weight of the robot as well. To do this, we decided that a latch made of a ratchet with two sprockets would solve both our strength issue and our driver countrol issue. A ratchet allows us to just approach the lander and move our intake up to engage the ratchet. Once engaged, if the driver wants to detach from the lander, like during the beginning of a match, the ratchet will detach if it is moved above the top to the hook. We designed this with PTC Creo, printed it, and began testing.

    An immediate issue we encountered was that the nylon would bend under stress and the bearings would pop out, causing the ratchet to fall apart. Our attempt to fix this was to move the bearings from the mount for the sprockets to the sprockets themselves. This way the bending nylon would slide across the hex shaft instead of popping out the bearings. We also changed the way the ratchet is mounted. The first design was mounted to a piece of polycarb, which didn't help the bending of the nylon. The new design is mounted onto flat aluminum bars that are attached to polycarb. This should restrict all the bending to the polycarb and make the nylon pieces more reliable. The new system had some errors in the locking mechanism that were fixed by trimming a few pieces. The new ratchet doesn't fall apart but it still isn't strong enough to support the robot under less than ideal circumstances. Another problem is that autonomous latching is difficult because the elbow moving with the base of the robot moves the ratchet with causes it to slide over the hook. Notice in the picture that the left side has the bearing slot in the sprocket, while the right side has the bearing slot in the frame.

    Next Steps

    We need look at ways to either strengthen our ratchet, or to find a new solution. We have looked at trying to CNC route the parts of the ratchet out of aluminum but we cant find a shop that will do that for us. A new solution would probably be to use standard parts to make a latch that is strong and easy to align with the lander. It's getting close to regionals, so we need to pick a design and improve it as much as we can. The ratchet latch currently isn't very reliable, so we aren't sure whether or not to keep making changes, or pick something simple that works more efficiently.

    Superman Calculations

    Superman Calculations By Ethan

    Task: Calculate torque and other values of the Superman arm on our robot

    We want to create a complete picture of our robot; that is, we want to have our robot completely replicable through the journal. So, we found it necessary to include the power calculations of various subsystems on our robot.

    Superman Arm

    The Superman arm uses two REV Core Hex motors to lift the robot upward, outputting a base 125 RPM and 6.4 Newton-meters of torque. Then, we have 15-tooth gears attached to the motors, which in turn connect to 125-tooth gears for a gear ratio of 10.4:1. Using the torque calculation WheelT=MotorT*(output/input), we find that the total torque exerted downward by the arm is 66.6 N*m.

    Then, given that the arm is .304 meters long, the upwards force produced by the Superman arm is 20.29968 Newtons. The robot itself weighs about 20 pounds, or 89 Newtons. But, since the robot is moving around its center axis, we can neglect the lower half of the robot that touches the ground with the wheels, reducing our load to 44.5 Newtons. Then, taking the integral of force with respect to the radius measured from the Superman arm, we integrate the equation force=(force at top/radius to top)*radius=292.763r. Using the limits defined by the distance to the edge of the robot (0 to .152 meters), the downward torque created by gravity is 3.38 N*m. Modelling the robot as a single point, we get this diagram.

    But, the robot doesn't always operate at optimal load. For example, when the robot is at maximum extension, there are about 60N of load above the center arm and the center arm itself is extended 18 inches, or .4572 meters. Performing the same integral as before with the new limits (0, .4572+.152=.6092), we find that the maximum possible downward torque exerted on the arm is 54.33 N*m, resulting in a net torque of 12.7 N*m upward. Superman can still raise the robot upward, but much slower and with a much greater probability of gear slippage. At these torque levels, the plastic teeth of the gears slip if they're not perfectly aligned.

    Given that the gears are composed of Acetal (Delrin/POM), that the area of one tooth is (.00104 meters * .011 meters = 0.00001144 m^2), that the arm produces 66.6 N*m * .152 m = 10.12 Newtons of force, and the Delrin/POM deformation chart, we can find that the pressure on *one* tooth of the gear is P=F/A=10.12/.00001144=884615.38 Pascals or .88461538 MPa. And, consulting the Delrin/POM deformation chart below, using the long-term line for an hour of use, we retrive a stress of ~.5%, meaning that the teeth of the gears deform by .5% per hour of use. This alone explains our gear slippage under high loads; as the pressure on a tooth increases, they cause more deformation, which in turn results less area contact between the teeth of the gears, which results in more stress, causing a negative feedback loop.

    However, this alone doesn't explain the stripping of the gears - the gears would only deform by .0572 uM; more analysis is required. When we inspected the superman gears more closely, we found that the gears barely interlocked - maybe 1% of the gears were touching. When we go back to the pressure equation, we find that this increases the pressure on each tooth to 88 MPa. Under the short-term compression curve below, we find the strain is about 5%, or 10x the strain. This results in a deformation of about 5uM, but the contact area itself is only 104 uM, so under these loads it causes an appreciable effect.

    This leads us to the natural conclusion to solve this issue - the gears must be held tighter to increase the contact area and decrease stripping. To do this, we're starting to design a gear holder, which will be detailed soon.

    Gearkeepers

    Gearkeepers By Jose and Evan

    Task: Create and intall gearkeepers to reduce slippage

    My first task as an Iron Reign member is to install gear keepers for the gears used for the Superman arm. Their purpose is to prevent gear skippage which can damage gears over time. They are 3D printed parts with bearings on their ends. Inserting these was as easy as sliding the shaft and then sliding them in.

    Now it was time to test for gear skippage. Unfortunataly, we got one or two gear skips with every attempt of rotating the wheel mount. We tried using string to see if tensioning the gear holders would work but that also failed. Next we tried to calculate the size needed for the gear holders to see if there is a slight size error. To calculate this we take the module of the gear and multiply it by the amount of teeth the gear has, we then divide by two to get the gear's radius. We do this for both gears and add them together. The module of the REV plastic gears is 0.75. This resulted to be (15×0.75/2)+(125×0.75/2) or 52.5 mm. And the original gear holders were 53 mm long, a slight error but at least we found the reason for error. We also noticed that there was some give in the plastic inserts for the REV bearings so we decided to tighten it down to 52mm.

    We changed the length of the inside of the gear holders from 53mm to 52mm and 3D printed them. This resulted in a complete fit where the gears were firmly engaged.

    Next Steps

    This is good for now but in the future, we need to watch the nylon of the gearkeepers for wear and tear as well as stretching - even a millimeter will allow the gears to slip.

    Mechanical Depositing

    Mechanical Depositing By Evan

    Task: Create a mechanical deposit for our selective intake

    To relieve driver stress, we decided we needed to put a mechanical release mechanism that would drop the minerals into the passive sorter to then further deposit them. The lever that activated the release mechanism was made of thick wire and attached to a small gearbox that reversed the direction of rotation for the release gate. The whole mechanism is based around a small release gate that rotates around a REV hex rod that was connected to the gearbox on the side. The lever activated the gearbox when it was pushed into the side of the lander. This created some issues that ultimately killed the mechanical release, such as a balance of tension that would never work out. We had to balance the tension of the rubber bands with the weight of the minerals while also accounting for the fact that the lever had to be pushed without our entire passive sorter being pushed beyond 180 degrees up and down. It was a task that couldn’t be done in the time we had, so we instead switched over to a servo which now powers the release gate. While short-lived it was a good test of the limits of our intake system, and we will be improving on it in the coming days.

    Next Steps

    We need to attach a servo to the intake with a correct mounting position to allow at-will depositing. We plan to do this with a inward-mounted servo which will then be connected to the REV hub through a wire protector, allowing us to place a servo high on the robot without worrying about the wires getting stuck in the gears and cut like before.

    Latch V.3.5 Assembly

    Latch V.3.5 Assembly By Ben

    Task: Assemble the V.3.5 latch and attach to the robot

    We assembled the fourth version of the latch today. Some of the improvements on this latch include using bigger bearings and thrust bearings inside. This latch is designed to be stronger and more reliable. After cleaning the parts and trimming some edges, we assembled the pieces. Once the device was fully assembled, we wanted to reattach the latch to the inside of the polycarbonate Brackets. But before we could mount it, we discovered an issue; the gears required a different amount of pressure to catch the lock. If left untreated, it could result in the robot falling off the hook. We determined the root of this problem was that the locking mechanism on the right gear was shorter than the left. To fix this, we trimmed a few millimeters off the piece that provides tension on the left gear to match that of the right gear.

    Older versions of the latch were previously mounted outside the polycarbonate bracket, but because the new latch had a c-channel bar on the back, we were unable to mount it to the front. We also needed more space, which we would achieve if we mounted it on the inside. On the previous latch, there were 2 metal bars on the top and bottom. These fit onto the brackets. We removed the bars from the previous latch and attached them to the new latch. These were too long and couldn't fit into the bracket, so we had to sand them down. This would allow them to fit inside the brackets, but even when they fit, the pre-drilled holes on the latch were too low. Our solution was to remove a portion of the bracket. We used a hacksaw to cut off a sliver of the bottom flaps, this allowed us to position the metal bar lower and attach it to the latch.

    Latch attached to polycarbonate brackets.

    Step-by-step instructions for building a latch:
    Step 1: Determine priorities. We wanted our new design to be smoother, stronger, and easier to operate.
    Step 2: Force your 3D modeler to model a design on a CAD software. We used Creo.
    Step 3: Print out your model.
    Step 4: Make the freshman build it. (They made Ben build it)
    Step 5: Test, but don't break it so the seniors don't yell at you.
    Step 6: Attach to robot.

    Next Steps

    We will need to perform various tests on the latch to determine if the height is correct, if the latch can support the robot, ease of latching and unlatching, and consistency. We plan to test our robot this Saturday at the DISD STEM Expo, which will provide an opportunity to practice latching.

    Fixing Mineral Dropper Components

    Fixing Mineral Dropper Components By Jose and Evan

    Task: Fix any issues with the mineral dropper

    At the STEM expo we saw a clear issue with the mineral dropper: it is very poorly geared and doesn't drop minerals when we want it to. A quick look at the gear configuration revealed that the gears were attached in a poor manner such that there was a lot of gear skippage. Thankfully REV gear boxes are the perfect size to support both gear to prevent such skippage. The gears have a small bearing at the ends to be inserted onto the entries on the gear box. The gear had to be placed between two of these gearboxes to be kept in place so we attached an extrusion to the second gear box and held both extrusion together with an extrusion holder.

    //picture

    The way the mineral dropper works is by having a wire attached to the shaft that turns the release be pushed when the robot hits the lander. The wire is attached with a portion of a gear custom cut for the job.

    //picture

    We need to upgrade to a thicker wire for more reliable shaft rotations. After doing so we needed a different wire holder and we chose a REV wheel. After cutting it and drilling bigger holes to accommodate the new wire we needed to attach it all to the shaft for the mineral release. A problem was that the thicker wire is harder to bend and we have a very small gap for it on the robot. I couldn't finish in time so that is left for next time.

    Next Steps

    We need to finish bending the wire and test its ability to open the mineral release when contacting the lander.

    Fixing Mineral Dropper Components

    Fixing Mineral Dropper Components By Jose and Evan

    Task: Fix any issues with the mineral dropper

    At the STEM expo we saw a clear issue with the mineral dropper: it is very poorly geared and doesn't drop minerals when we want it to. A quick look at the gear configuration revealed that the gears were attached in a poor manner such that there was a lot of gear skippage. Thankfully REV gear boxes are the perfect size to support both gear to prevent such skippage. The gears have a small bearing at the ends to be inserted onto the entries on the gear box. The gear had to be placed between two of these gearboxes to be kept in place so we attached an extrusion to the second gear box and held both extrusion together with an extrusion holder.

    The way the mineral dropper works is by having a wire attached to the shaft that turns the release be pushed when the robot hits the lander. The wire is attached with a portion of a gear custom cut for the job.

    We need to upgrade to a thicker wire for more reliable shaft rotations. After doing so we needed a different wire holder and we chose a REV wheel. After cutting it and drilling bigger holes to accommodate the new wire we needed to attach it all to the shaft for the mineral release. A problem was that the thicker wire is harder to bend and we have a very small gap for it on the robot. I couldn't finish in time so that is left for next time.

    Next Steps

    We need to finish bending the wire and test its ability to open the mineral release when contacting the lander.

    Drive Testing at STEM Expo

    Drive Testing at STEM Expo By Ben and Abhi

    Task: Test robot performance at the STEM Expo

    An FLL team gathered around Iron Reign’s robot

    We had the privilege of being a vendor and representing SEM at DallasISD’s STEM Expo this weekend. Thousands of people cycled throughout our area during the day, so we had the opportunity to show off our robot to many people. Some of these people include FLL and VEX IQ teams, along with Best Buy volunteers. Our goal was to get kids excited about STEM and robotics, along with getting some robot practice in. We will be trying out the new latch, new presets, and prospective drivers.

    As soon as we started driving, we noticed a few issues. One of these being the belt drive repeatedly slipping. This may be a result of the belt loosening, the drive gear accelerating too quickly, heavy intake arm, or the preset causes the drive gear to keep operating, even when the arm is fully extended. We also struggled with keeping the intake box out of the way and prevent it from twisting around the “corn on the cob” intake. We will solve this by fastening the rubber band that was supposed to keep it in place. This; however, wasn’t our only intake problem. Once 2 minerals had been grabbed, they would usually fall out the intake box after lifting the arm. The intake box would turn vertical, making it easier for the minerals to shift out. This was especially an issue when trying to deposit the minerals, we would make several sudden movements, causing the arm to swing and minerals to fall out. A possible solution to this is adding a barrier between the floor of the intake box and the top of the box. This would allow for more freedom, as we could move faster without worry of losing minerals.

    Demonstrating intake arm for FLL kids

    Next Steps

    It will take a lot more practice to master latching and collecting, and even general driving. We will need to code better presets and either design a better collection box, or fix the existing one. Drivers will also have to be selected, which we will do by running several trials for each member and determining who is best at latching, scoring, and control.

    Latch 2.0 - Forged in Flame

    Latch 2.0 - Forged in Flame By Evan

    Task: Design a new latch for hanging

    Our latching system is too complicated to use quickly. It just is. It requires too much reliance on driver control and on occasion, it can become jammed and refuse to push. Our solution? Forge an iron hook to replace it. We started by taking an 8mm iron rod and thrusting it into the forge that we have, heating it up and bending it into shape over the course of an hour. I definitely learned a ton about forging, since up until now most things I had made in there had no need to be precise and I didn’t really have much idea of what I wanted to do going into it. This time, however, I made a wire model for the hook, and then slowly and patiently formed the hook out of the rod. Then, to make an easy-to-drill connection point, we heated a section up until it was white hot and then used a punch to create a flat part that we then drilled into afterward. The whole process was definitely enlightening and overall I had a really good time learning the specific techniques used, such as letting the metal air-cool instead of dipping it into to water to allow for a less rigid part. Once all the metallurgy was done, it was on to creating a mount for it.

    To do this, we took a length of steel and used an oxy-acetylene torch to heat up the areas we wanted to bend. We didn’t use the forge this time, since it typically heated over a large area, whereas in this case we only needed it to be heated at the joints for the more local bends we were doing. We had to make two of these though, as the first one was not bent as we had thought it was and jerked off to one side. Once this was done, we went about attaching the hook to the mount. We did this by finding the center of the mount, drilling it out, and pushing a bolt through it, surrounding all sides with washers. We then mounted a servo next to the hook and attached it with a piece of wire, which was secured to the hook by two notches cut out of either side of the tail of the hook. Later, after finding the wire to be too flimsy, we attached the two together with a strip of polycarb. The whole thing works well, allowing us to mount and dismount much easier than we would have hoped for with our last latch. While the last latch was purely passive and required no electrical components, this one gives us much more control in how we latch and delatch, something that, not that we have it, we realize was much needed from the start.

    Next Steps

    Bigwheel Model

    Bigwheel Model By Justin

    Task: Design and update the Bigwheel Model

    We are working on updating our BigWheel 3D model to include chassis changes and our new intake and lift system. We have an older bigwheel model from the chassis study over the summer that we are modifying to match our competition robot. So far we have added on the intake and sorting system, the lift, and the superman arm. The lift however, has recently been modified twice and the model needs to be updated. The main issue we are having with the model is correctly placing the motors on the model because the lift motors are spaced oddly and mounted on a gear connected to the REV rail supports, which extend from the chassis. This makes it difficult to find the right orientation and spacing of the motors on the model.

    We were updating the old rev rail linear slide to our custom slide and pivot system when we switched lifts again. The new lift uses carbon fiber rods to support the weight of the intake system, which has also changed from the passive sorting mechanism to a miniature corn on the cob. In addition to carbon fiber rods, we also added a new alternative linear slide system. The challenge is that there are no cad files that match the slides we used. We have been working on modeling the slide as well as the pieces that attach the intake to the slide.

    Next Steps

    The slide parts are not standard in FTC so we need to custom model the new slide and it's components. We designed a custom ratchet system that will allow the robot to slide onto the lander hook and lock it there to allow it to lift itself. We will add this and a few other small 3D printed support brackets to the robot, as well as the polycarb mineral storage system once we pick a final version. The model is only missing the intake and some small custom parts. We hope the 3D printed parts will be easy to add to the model but the new slide system and intake will definitely be a challenge.

    BigWheel Upgrades

    BigWheel Upgrades By Evan

    Task: Fix some issues on BigWheel before the build freeze

    The robot in a whole is getting stronger each day. All the subsystems work well, but they could work better, which is what I have devoted myself to fix. All the major systems are on a build freeze, and I can no longer make large changes to the robot, so now it’s time for all the much needed little ones that will more finely tune the robot hardware. I started my quiet Sunday evening by making a much more secure way of activating our hook, switching our piece of wire attaching the servo to the hook with a much stronger and less likely to bend strip of polycarb, which greatly improved the reliability of the hook. I then worked on limiting the back and forth motion of our slides at their attaching points. I achieved this by inserting a small piece of drywall sandpaper in between the stages of the slides. Hopefully, the added friction will create a stronger hold between the stages fo the slide. Next, I fixed some servo issues with the gate on the intake system, namely grinding down a bolt to more securely attach the servo horn to the servo since it’s a REV hex shaft to servo adapter and the bolts we had didn’t fit inside well enough. Once that was done, I finished my evening off by changing the ratio between the belt drive pulleys, going from a 1:1 (36 teeth to 36 teeth) to a 5:3 (60 teeth to 36 teeth) by increasing the size of the pulley at the motor. This should increase the quickness of our lift and hopefully let us squeeze a few more mineral pick up and depositing cycles in. The evening ended successfully, and the next major minor fix will be replacing all the gears on our arm since they’re wearing out over time.

    Next Steps

    It's time to turn the robot over to the coders and drivers, so there won't be many changes after this,

    Pulley Spacers

    Pulley Spacers By Ethan

    Task: Design and implement pulley spacers to prevent belt interference

    So, we had an issue where the belts that allowed our arm to slide upward were misaligned, resulting in the belts frequently slipping. We narrowed the slippage down to a single point, at this pulley.

    So, we decided that we had to create a new spacer to keep that section of the belt inline with the rest. As usual, we took measurements and replicated them in Creo. It had to be about 3.5 centimeters long, the same width of the metal plate. The depth of the indentation to attach to the linear slide is about 0.75 centimeters and the diameter of the M3 holes 3 millimeters. With these measurements, we designed the piece and printed it in 60% infill nylon, strong enough to withstand the weight of the linear slides. This is what version one looks like:

    However, this version's holes were too far down, allowing the toothed sections of the belts to interact and jam. So, we decreased the height of the bottom pulley-holes so that the middle section of the belt would slider higher up, preventing intereference. This resulted in the final version seen at the top of the article.

    Next Steps

    We still have to fully test these spacers, but we can't do a full test until we fix the gears supporting the elbows, which will be detailed in another post.