Articles by tag: innovate

Articles by tag: innovate

    Swerve Drive Experiment

    Swerve Drive Experiment By Abhi

    Task: Consider a Swerve Drive base

    Last season, we saw many robots that utilized a swerve drive rather than the mecanum drive for omnidirectional movement. To further expand Iron Reign's repertoire of drive bases, I wanted to further investigate this chassis. Swerve was considered as an alternative to swerve because of its increased speed in addition to the maneuverability of the drive base to allow for quick scoring due to its use of traction wheels at pivot angles. Before we could consider making a prototype, we investigated several other examples.

    Among the examples considered was the PRINT swerve for FTC by team 9773. After reading their detailed assembly instructions, I moved away from their design for many reasons. 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 was not functional or if the chassis didn't make sense to use in Rover Ruckus, we would have almost no money for an alternate drive train. Also, they parts used by 9773 involved X-rail rather than extrusion rail from REV. This would cause problems in the future as we would need to redesign the REVolution system for X-rail.

    Another example was from team 9048 which appeared to be more feasible. Because they used REV rail and many 3D printed parts, this was a more feasible prototype. 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.

    At this point it was evident most swerve drives being used are very expensive. Wary of making this investment, I worked with our sister team 3734 to create a budget swerve with materials around the house. A basic sketch is listed below.

    Next Steps

    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

    Over the past week, 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.

    Immediately 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 chassis 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 at this time.

    Next Steps

    Consider and prototype other chassis designs until Rover Ruckus begins.

    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 opportunity 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. We 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. Here is a drawing of what we plan the chassis to look like:

    To make this chassis the most efficient based on what we currently know about the competition (light weight robot needed) we are planning to do different tests and calculations to determine the proper motor-gear ratio needed and the wheel locations to properly balance the robot. We also need to perform tests to determine the best material to use for the robot. In the past we've used REV rails for the majority of our structure but due to the weight limit on our robot we plan to minimize metal in our design rather opting for materials that are just as functional but weight less.

    Next Steps

    Perform calculations comparing different motors as well as different wheel ratios to determine the optimal ratios

    Position Tracking

    Position Tracking By Abhi

    Task: Design a way to track the robot's location

    During Relic Recovery season, we had many problems with our autonomous due to slippage in the mecanum wheels and our need to align to the balancing stone, both of which created high error in our encoder feedback. To address this recurring issue, we searched for an alternative way to identify our position on the field. Upon researching online and discussing with other teams, we discovered an alternative tracker sensor with unpowered omni wheels. This tracker may be used during Rover Ruckus or beyond depending on what our chassis will be.

    We designed the tracker by building a small right angular REV rail assembly. On this, we attached 2 omni wheels at 90 degrees to one another and added axle encoders. The omni wheels were not driven because we simply wanted them to glide along the floor and read the encoder values of the movements. This method of tracking is commonly referred to as "dead wheel tracking". Since the omnis will always be touching the ground, any movement will be sensed in them and prevents changes in readings due to defense or drive wheel slippage.

    To test the concept, we attached the apparatus to ARGOS. With some upgrades to the ARGOS code by using the IMU and omni wheels, we added some basic trigonometry to the code to accurately track the position. The omni setup was relatively accurate and may be used for future projects and robots.

    Next Steps

    Now that we have a prototype to track position without using too many resources, we need to test it on an actual FTC chassis. Depending on whether or not there is terrain in Rover Ruckus, the use of this system will change. Until then, we can still experiment with this and develop a useful multipurpose sensor.

    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 code base 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 separating 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.

    Choosing Drive Train

    Choosing Drive Train By Janavi

    Task: Analyze the game

    In our last post, we created a chart where we listed each task asked based on point value and the level of difficulty, separated by autonomous and teleop. Our goal is to find a drive train that will allow us to build a robot to accomplish all of these tasks efficiently and consistently, but this matrix will allow us to determine what to focus on first.

    Drivetrain Comparison

    This summer we created a variety of drivetrains for a summer chassis project hosted in coordination with other teams from the North Texas region. We have compiled a list of the drivetrains and the criteria we need to consider for Rover Ruckus.

    What do we need to look at in a Drivetrain?

    • Light
    • Sturdy
    • Easily Maneuverable
    • Fast
    • Low center of mass to avoid tipping
    • Reliability

    Comparison

    Eliminated? Reason for Elimination Pros Cons
    Miniature Mechanum Drive NO N/A
    • Omni-Directional
    • Fast turning
    • Easy to design
    • Experience with
    • Driving/Building
    • light
    Uneven power
    Big Wheel NO N/A Unique Design We have less experience
    Larger Mechanum Drive YES Need light robot; may use mini mechanum chassis instead Familiar Design Too heavy for this years competition
    Swerve YES Difficult design, Many motors and servos, we have less experience Easier to maintain at high speed Unfamiliar and difficult to design and maintain
    8-wheel Drive YES Many wheels, Difficult of maneuver, no omni directional movement 100% power forward Difficult to maneuver
    Holonomic Drive YES Less push power in all directions; hard to integrate into robot Easy to turn and maneuver Hard to design; hard to integrate into base; Only 50% power in all directions

    Selecting Wheels

    Selecting Wheels By Janavi

    Objective: Determine the type of wheel that best suits the chassis

    In the Choosing Drive Train E-16 we decided that we will use the chassis BigWheel. We know that our wheels need to be light weight but we need to determine the size of the wheel that will keep our robot far away enough from the ground for us to provide enough clearance to allow us to climb over the crater rim. But, if we choose wheels with a large radius we risk raising the center of mass.

    Pros Cons
    Ironton 12in. Solid Rubber Spoked Poly Wheel
    • light
    • durable
    • Large Turns
    • Extremely Large
    Ironton 16in. Solid Rubber Spoked Poly Wheel
    • light
    • durable
    • Raise center of mass
    • Extremely Large
    • To prevent tipping we now have a much shorter distance to correct imbalance
    Ironton 8in. Solid Rubber Spoked Poly Wheel
    • light
    • durable
    • Not large enough to significantly move the center of mass

    Brainstorming Two

    Brainstorming Two By Evan, Abhi, and Janavi

    Task: Have a 2nd brainstorming session

    We had another brainstorming session today, which allowed us to break down into some new building tasks.

    Intake System 3 - TSA Bag Scanner

    This part of our robot is inspired by the bag-scanning machine in TSA lines, 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.

    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 separator, 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.

    BigWheel Chassis

    BigWheel Chassis By Evan

    Task: Work on a possible chassis

    We've been toying around with the idea of using BigWheel, our Summer Chassis Research Project bot, in this year's competition with a few modifications. 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

    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

    To increase the efficiency of our robot, we looked into ways to passively sort minerals during intake and deposit. It is important to sort because it requires less precision under driver control allowing a faster and more efficient robot. Though bulky, we designed an initial design to sort the minerals.

    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 modeled this design in PTC Creo, then printed it in ABS.

    Next Steps

    This design works but is large so we're going to have to find a smaller and simpler way to sort game pieces. In the future, we're going to minimize this and probably move to a smaller sorting mechanism.

    BigWheel+

    BigWheel+ By Evan

    Task: Continue work on BigWheel

    BigWheel has gone through a few major changes. First and foremost, it now has a flipper arm, AKA Superman. Since the robot itself is the lift mechanism, we had to put a lot of work into Superman's design. Right now it is a 10 inch REV rail attached to two 125-tooth gears for redundancy, with a custom 3D printed mount housing an pair of omniwheels on the other end. On the motors, we have two 15-tooth gears, resulting in a 3:25 gear ratio. This gives us a ridiculous amount of torque that lifts the robot up smoothly. 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 we'd dealt with wires getting stuck in the gears.

    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 Mecanum Chassis

    Mini Mecanum Chassis By Janavi and Justin

    Task:

    Over the summer, we designed many robots for the North Texas Chassis Project, including one based off of last year's Worlds robot, Kraken. The robot chassis had 6" mechanums. But, based on what we know about this years challenge we have decided that this chassis does not utilize the 18-inch cube effectively.

    We have chosen to design a chassis that is similar in function to Kraken, but smaller in size with 4" mecanum wheels.

    Our plan is to design a low-lying 6" x 6" robot, a marked difference from the usual 18". However, this new design means that many of our 3D printed parts are unusable on this robot; for example, our former wheel mounts are much too large for the new robot and wheels, as well as their corresponding axles.

    These bearings are hexagonal, requiring a new wheel mount design.

    Justin first designed the axle plate below to solve this, but it raised the robot off the ground quite a bit, risking debris becoming stuck under the bot. As well, it was flimsy - it was mounted too far from the robot. We went back to the drawing board and brainstormed various methods we could use to attach the axle the frame in a more secure way; we found that we use a pillow block design 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've switched to NeverRest 20s in lieu of our normal 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

    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. So, we designed 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 Iron Reign's 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.

    BigWheel Arm

    BigWheel Arm By Evan

    Task: Design an arm for BigWheel

    Bigwheel’s intake arm is one of the most important parts of the robot. Since our scrimmage, we have learned how to make this arm much more efficient, starting with some supports. The original intake arm was made of two scrap Tetrix rails. The result of this was that the two sides of the arm would be out of sync, creating a twist in the arm that caused it to move oddly. Thus, it has been stabilized with cross beam REV rails.

    The next upgrade on the arm is going to be the box to hold the minerals. Right now it’s just a cardboard prototype and we need to move to the next version. After a bit of debate, we decided to craft it out of polycarb. 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.

    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 Calculations

    Torque Calculations 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.

    BigWheel Upgrades

    BigWheel Upgrades By Evan

    Task: Get BigWheel ready for the tournament

    Today, we built mounts to attach both types of intake to the rack; the rack-and-pinion corncob intake and the red-flapped intake. We also created a new way of mounting the arm to the chassis. 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. We made the arm with a 12-86 gear ratio. Our next plan is to create the mount, minimizing the size of the arm.

    The final addition 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 in case 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.

    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 that allows for greater modularity and functionality.

    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.

    The main way to prevent the wobbliness is by replacing the polycarb with something 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 aluminum 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 separate 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.

    Selecting Lift System

    Selecting Lift System By Janavi

    Objective: Determine the type of lift system will allow us to delatch and reach the lander

    In our past post Choosing Drive Train we decided that we will use the chassis BigWheel. After deciding the base we need to now think about the lift system that we want to use to allow us to both deposit into the lander and latch onto it. Evan and I have been experimenting with linear slides to use for our lift. I have been working on a REV linear slide lift system as referenced in the post "Linear Slide Lift". Evan has been working on a separate ball bearing linear slide. As well as these two options we are looking into past linear slides and ones that we have seen teams use in past challenges. We need to determine which of the linear slides works best based on the game requirements this season

    Linear slides needs according to game
    • Lift and lower robot from latch on lander
    • Extend out to Crater from distance to collect minerals
    • Extend out vertically to lander to deposit minerals

    What we want our linear slide to have
    • Light Weight
    • Bidirectional (Able to collect from crater and deposit)
    • Speed
    • Sturdy
    • Easy to fix and maintain in case of emergency
    • Small in size
    • Extend out to around 5 ft in height

    Linear Slide Options
    • Ball Bearing Lift
      • Heavy
      • Smooth
      • Reliable
      • Never used the before
    • Drawer Slides
      • Heavy
      • Low cost
      • Unwieldy
      • Familiar as we used them last year
    • REV Linear Slides
      • Light Weight
      • Not very reliable
      • Familiar

    Next Steps

    We need to select the best linear lift system for our chassis based on the requirements we set above.

    Code Issues Break the Superman Arm

    Code Issues Break the Superman Arm By Abhi

    Task: Analyze the code issues that led to our robot breaking

    After constant use, our robot's Superman arm broke. At this point, it is important to analyze our failures. This error was not because of a build issue but rather a code and driver control issue.

    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. 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 intend 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

    This is a follow up to Post E-64, Code Issues Break the Superman Arm. 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.

    Selecting Intake System

    Selecting Intake System By Janavi

    Objective: Determine the type of intake system that will allow us to efficiently obtain and deposit minerals within the lander

    In our post "Selecting Lift System" we decided that the linear slide system that we will use is the MGN12H rails also referenced to as the Ball-Bearing slides. These slides while heavy provide the smoothest option. now that we have chosen the Lift system we need to determine the intake system that will allow us to take in two minerals and deposit them in the most efficient way possible. Throughout this season already we have been experimenting with different types of intake systems as seen in posts like "Pool noodle intake" and "Selective Intake" and "Scoring Mechanism"

    Intake System needs according to game
    • Collect only two minerals
    • Sort between silver and gold minerals

    What we want our linear slide to have
    • Light Weight
    • Speed of intake mechanism
    • Sturdy
    • Easy to fix and maintain in case of emergency
    • Small in size

    Passive Deposit vs Passive Intake

    Pros Cons
    Passive Deposit Faster intake Could be unreliable if not positioned correctly
    Passive Intake More accurate Harder to intake and therefore we score less

    Intake Mechanism Material / Shape

    Pros Cons
    Ice Cube Tray Compliant and smooth Not a far reach
    Surgical Tubing Farther reach Possibility of missing minerals due to sporadic behavior of surgical tubing
    Pot holder Brings in minerals Not far reach and too compliant
    Octopuckers ( from last year's season ) Experience with using material Too stiff and not far enough reach

    BigWheel Arm Locks

    BigWheel Arm Locks By Evan

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

    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 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.

    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 originally tried to overlap 3 rectangles, and Creo didn't register it as an enclosed shape and wouldn't extrude. 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, Our models printed in roughly 30 minutes using nylon on a Taz printer.

    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

    Early in the season, we made a hook, Although it was durable, it required a higher amount of precision 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 it is a much more secure, closed system, and doesn’t require stringing. 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. 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 difficulties in tensioning.

    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.

    Latch Updates

    Latch Updates By Justin, Abhi, and Ben

    Task: Update the latch

    Our first attempt at a latch was made out of flat metal L brackets that would slide into the hook, but they slid off under any stress. We decided to make a latch with a ratchet and sprocket system. The easiest way to accomplish this was to 3d print it. There are two sprockets and the lander hook will slide in between them. This causes the sprockets to rotate and then lock, allowing the latch to support the weight of the robot. To disengage, the driver just needs to move the ratchet up and over the hook. The picture of the model shows our change in design because the right sprocket is mounted to a bearing in mount, while the left side has the bearing in the sprocket.

    The purpose of our new latch is to increase the speed of latching. The latch requires one direction of motion to fully engage it, making it perfect for autonomous. The latch also has room for error because the funnel shape of the fron plates guides the hook into the sprockets.

    Issues

  • bearings pop out under stress(fixed by moving bearings from sprocket mount to sprockets)
  • whole subsystem bends under stress(fixed by mounting the latch to aluminum instead of polycarb)
  • difficulty turning ratchet(fixed by trimming pieces)
  • Still not strong enough to support weight of robot in a match
  • Hard to get close enough to lander to engage ratchet
  • Next Steps

    We need to either strengthen our current design or find a better alternative.

    Gearkeepers

    Gearkeepers By Jose and Evan

    Task: Create and install gearkeepers to reduce slippage

    We need to install gearkeepers on the Superman arm to prevent gear skippage which damages gears over time. We designed a simple rectangle in PTC Creo and cut holes to fit bearings, 3D-printed them, and attached them.

    Now it was time to test for gear skippage. Unfortunately, we had 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.

    We went back to the drawing board and checked for a sizing error. To calculate this we take the module of the gear and multiply it by the amount of teeth the gear has, then dividing 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.

    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. Upon assembly, 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.

    Latch attached to polycarbonate brackets.

    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 deposit minerals well. 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. To remedy this, we attached a gear-box to the dropper to keep the gears interlocked.

    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.

    Next Steps

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

    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 requires too much reliance on driver control and becomes jammed. So, we forged an iron hook to replace it. We started by taking an 8mm iron rod and placing it into the forge that we have, heating it up and bending it into shape over the course of an hour. We 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.

    To create a mount, we took a length of steel and used an oxy-acetylene torch to heat up the areas we wanted to bend. 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. It 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.

    Bigwheel Model

    Bigwheel Model By Justin

    Task: Design and update the Bigwheel Model

    We are updating our bigwheel model to represent our current robot. We had a model of just the chassis from the chassis study, so we are currently adding all of the changes we made throughout the season.

    Completed Changes

  • Added current intake
  • Added sorting system
  • Modeled the linear slide lift
  • Modeled superman arm
  • Future Changes

    The lift has been changed recently so the model needs to be updated. The main problem with this is that the new slides are not standard parts, so there are no accurate CAD files. This means we have to custom model our new slides to maintain accuracy with our model. The motor placement on the chassis needs to be fixed because we the measurements were estimates. There are many small 3d printed parts that need to be added to the robot, as well as our new ratchet latch.

    Next Steps

    We need to work on future changes and get our model up to date with our robot so we can start conceptualizing new subsystems.

    Elbow Rebuild

    Elbow Rebuild By Ethan, Jose, Karina, and Ben

    Task: Rebuild the elbow after total gear annihilation

    In a previous post, we detailed the extent to which we had stripped our gears - they were missing teeth in several places and the black anodization layer had completely stripped away. So, we had to replace them. The first order of action was to design gearkeepers for them. We've designed gearkeepers before, for the Superman arm, but these have different requirements. They must connect the gears on both elbow driver and slave, but also must mount to the robot itself to prevent the motor shaft from wobbling, which had previously caused major issues. We came up with this design, printing it out in 60% infill nylon.

    The next thing to do was replace the actual gears. To do so, we had to dismantle the entire elbow and replace the gears and shaft collars. This alone took about two hours per side. We added the new gears, ensuring that they were in alignment, and printed a circular part to mount the top of the gears to the linear slide so that the entire system would rotate when the gears were turned. Then, we remounted the belts and aligned them. After, we attached the new gearkeepers, ensuring that the gears interlocked perfectly.

    Next Steps

    So far, we haven't experienced issues with the new elbow, but we're getting our hands on a new set of gears to be safe. We expect this system to continue to work for the Regional tournament, and are performing drive practice to ensure this.

    Latch Designs - A Retrospective

    Latch Designs - A Retrospective By Ethan

    Task: Analyze past successes and failures in our latching system

    Version 1

    The first version of the latch worked decently. We started out with the idea of a one-way, passive latch. This idea involved mounting smaller bearings and gears between them, with a spring-like nylon piece that moved only when downward pressure was placed upon the gears. This design was only fully realized before the Wylie Qualifying tournament, and only tested the night before. We found that the bearings popped out under pressure necessitating a reset after every match and meaning that we could only latch once per match. We opted for the endgame latch, as it was more reliable. But, this cut the amount of points we could receive immensely. After the tournament, we decided to do a full redesign.

    Version 2

    The second version's changes were simple. We redesigned the nylon "spring" and made it thicker and more prominent. This made it so the latching gears were more firm than before, which in turn allowed more weight to be put on them. However, the issue with the gears was still present; as the load on the latch increased, the nylon would bend more and more, allowing the bearings to fall out so that the latch would jam in place. This version was quickly scrapped.

    Version 3

    At this point, we were sick of the bearings popping out. So, we widened the holes immensely to fit larger bearings which in turn had larger holes allowing for bolts to be run through. This was overkill, but it ensured that no slippage would occur during normal robot usage. Again, we also thickened the nylon "springs" so that the gears would stay in place without significant upward force.

    We realized, that while technically impressive, the latch as we knew it had to go. It worked, but it was too time-costly to justify using, as the driver had to precisely line up the bot next to the lander to use it, taking about 20 seconds. In addition, it was difficult to code as it required several intricate simultaneous robot operations: the lift needed to descend at the exact same moment Superman needed to rotate, all while the elbow rotated the robot 90 degrees. In summary, it was an overly burdensome task. So, we threw away all that work, these past two months of labor in favor of a simpler option.

    Version 4 - the Hook

    We decided that it was time to go back to the drawing board. In time periods, it was approximately a jump from the current era to the Iron Age. So, we designed appropriately. We designed a stainless steel hook, first making one out of prototyping wire. Then, we heated up the forge, adding plenty of coke, and set to work. We chose a stainless steel rod, 8mm in diameter and warmed it to red hot, beating out the initial design. We let the initial rod air cool so that it would be soft enough to drill through, creating the mounting point for the robot. Then, we reheated it to its critical point (when it loses its magnetic properties) and quickly quenched it to reharden it. But, simply quenching it makes the steel too brittle to use in competition, so we finished up the hook by tempering it, using an oxy-acetyline torch on it until the surface became matte. Finally, we had the hook seen above. After all that work, we'd gone with the simplest option because sometimes, it is the best.

    Big Wheel Articulations

    Big Wheel Articulations By Abhi

    Task: Summary of all Big Wheel movements

    In our motion, our robot shifts multiple major subsystems (the elbow and Superman) that make it difficult to keep the robot from tipping. Therefore, through driver practice, we determined the 5 major deployment modes that would make it easier for the driver to transition from mode to mode. Each articulation is necessary to maintain the robot's center of gravity as its mode of operation shifts.

    The position seen above is called "safe drive". During normal match play, our drivers can go to this position to navigate the field quickly and with the arm out of the way.

    When the driver control period starts, we normally navigate to the crater then enter the intake position shown above. From this position, we can safely pick up minerals from the crater.

    From the intake position, the robot goes to safe drive to fix the weight balance then goes to the deposit position shown above. The arm can still extend upwards above the lander and our automatic sorter can place the minerals appropriately.

    During the end game, we enter a latchable position where our hook can easily slide into the latch. After hooked on, our robot can slightly lift itself off the ground to hook.

    At the beginning of the match, we can completely close the arm and superman to fit in sizing cube and latch on the lander.

    As you can see, there is a lot of articulations that need to work together during the course of the match. By putting this info in a state machine, we can easily toggle between articulations. Refer to our code snippets for more details.

    Next Steps

    At this point, we have 4 cycles in 1 minute 30 seconds. By adding some upgrades to the articulations using our new distance sensors, we hope to speed this up even more.

    Up-to-Date Bigwheel Model

    Up-to-Date Bigwheel Model By Justin

    Task: Finish the Bigwheel model

    Updating the Bigwheel model to the robot’s current configuration was a challenge. The new linear slides are not standard parts, so we had to model them from scratch. There was some cleaning up that was needed on the drivetrain of the model. This was mainly attaching floating motors to motor mounts and axles to bearings. These were mainly cosmetic changes, but they help define the purpose of the different parts of the drivetrain. We also updated the intake assembly to our current ice cube tray intake. The structure of the intake was easy to model but the ice cube tray gave us some trouble with its unique shape and pattern. The ratchet latching system was a failure, so a new hook model was needed. The main issue with this was that we custom forged our new hook, so there was some difficulty in getting the model to accurately represent the capabilities of the hook. Another challenge was the mineral storage system. This is made from polycarb pieces and has many unique pieces, so arranging the pieces to accurately show the flow of minerals was difficult.

    In addition to updating the model, we also learned how to show the different movements of the robot with the model. Mechanical constraints were added to allow certain parts to slide or rotate. The one problem we had with this was that there were no limitations to how far something could slide or rotate, so many parts of the model would disconnect and be left floating. After some research, a solution was found. Zero points were created for each moving part and minimum and maximum movement limits were added. Some parts that now can move on the robot are the wheels, superman arm, hook, and linear slides. This allows us to not only show the movement of the robot, but also the limitations of its parts, which can help us visualize new solutions to our remaining problems.

    Next Steps

    Our next step is to wait for more build changes, so we can keep updating the model. Another addition we might make is making stress maps of the robot in different configurations to see where parts might fail. This has been an ongoing challenge of keeping the model accurate when the robot gets updated or rebuilt, and now we finally have a finished model and ready robot for regionals.

    Road to Worlds Document

    Road to Worlds Document By Ethan, Charlotte, Evan, Karina, Janavi, Jose, Ben, Justin, Arjun, and Abhi

    Task: Consider what we need to do in the coming months

    ROAD TO WORLDS - What we need to do

     

    OVERALL:

    • New social media manager (Janavi/Ben) and photographer (Ethan, Paul, and Charlotte)

     

    ENGINEERING JOURNAL: - Charlotte, Ethan, & all freshmen

     

    • Big one - freshmen get to start doing a lot more

     

    • Engineering section revamp
      • Decide on major subsystems to focus on
        • Make summary pages and guides for judges to find relevant articles
      • Code section
        • Finalize state diagram
          • Label diagram to refer to the following print out of different parts of the code
        • Create plan to print out classes
        • Monthly summaries
      • Meeting Logs
        • Include meeting planning sessions at the beginning of every log
          • Start doing planning sessions!
        • Create monthly summaries
      • Biweekly Doodle Polls
        • record of supposed attendance rather than word of mouth
      • Design and format revamping
        • Start doing actual descriptions for blog commits
        • More bullet points to be more technical
        • Award highlights [Ethan][Done]

    Page numbers [Ethan][Done]

        • Awards on indexPrintable [Ethan][Done]
      • Irrelevant/distracting content
        • Packing list
        • Need a miscellaneous section
          • content
      • Details and dimensions
        • Could you build robot with our journal?
        • CAD models
        • More technical language, it is readable but not technical currently
    • Outreach
      • More about the impact and personal connections
      • What went wrong
      • Make content more concise and make it convey our message better



    ENGINEERING TEAM:

     

    • Making a new robot - All build team (Karina & Jose over spring break)

     

      • Need to organize motors (used, etc)
      • Test harness for motors (summer project)
    • Re-do wiring -Janavi and Abhi
    • Elbow joint needs to be redone (is at a slight angle) - Justin/Ben
      • 3D print as a prototype
        • Cut out of aluminum
      • Needs to be higher up and pushed forward
      • More serviceable
        • Can’t plug in servos
    • Sorter -Evan, Karina, and Justin
      • Sorter redesign
    • Intake -Evan, Karina, Abhi, Jose
      • Take video of performance to gauge how issues are happening and how we can fix
      • Subteam to tackle intake issues
    • Superman -Evan and Ben
      • Widen superman wheel
    • Lift
      • Transfer police (1:1 to 3:4)
      • Larger drive pulley
        • Mount motors differently to make room
    • Chassis -Karina and a freshman
      • Protection for LED strips
      • Battery mount
      • Phone mount
      • Camera mount
      • New 20:1 motors
      • Idler sprocket to take up slack in chain (caused by small sprocket driving large one)
    • CAD Model



    CODE TEAM: -Abhi and Arjun

    • add an autorecover function to our robot for when it tips over
      • it happened twice and we couldn’t recover fast enough to climb
    • something in the update loop to maintain balance
      • we were supposed to do this for regionals but we forgot to do it and we faced the consequences
    • fix IMU corrections such that we can align to field wall instead of me eyeballing a parallel position
    • use distance sensors to do wall following and crater detection
    • auto paths need to be expanded such that we can avoid alliance partners and have enough flexibility to pick and choose what path needs to be followed
      • In both auto paths, can facilitate double sampling
    • Tuning with PID (tuning constants)
    • Autonomous optimization



    DRIVE TEAM:

    • Driving Logs
      • everytime there is driving practice, a driver will fill out a log that records overall record time, record time for that day, number of cycles for each run, and other helpful stats to track the progress of driving practice
    • actual driving practice lol
    • Multiple drive teams

     

    COMPETITION PREP:

    • Pit setup
      • Clean up tent and make sure we have everything to put it together
      • Activities
        • Robotics related
      • Find nuts and bolts based on the online list
    • Helping other teams
    • Posters
    • Need a handout
    • Conduct in pits - need to be focused
    • MXP or no?
    • Spring break - who is here and what can we accomplish
    • Scouting

     

    VEX 393 Motor Testing

    VEX 393 Motor Testing By Jose, Cooper, Aaron, and Janavi

    Task: Test VEX Motor 393 as a faster servo for intake

    We need to speed up our intake to spend less time in the crater collecting minerals. We can accomplish this using VEX 393 Motors with high speed gears integrated, these motors are great since they count as servos, not motors. In terms of progress, this is what we did:

    • Tested VEX Motor 393 with servo cable on BigWheel
    • Resoldered XT-30 for servo power injector cable
    • Built new cable for servo power injector
    • Did research on VEX Motor 393 Controller to find out how it works
    • Replaced gears of VEX Motor 393 with high speed gears
    • Researched how to troubleshoot VEX Motor Controllers
    We are having issues implementing these motors onto BigWheel and our troubleshooting efforts did not suffice our needs.

    Next Steps

    We need to plan how to replace the servos on the intake with the VEX 393 Motors and test their functionality.

    New Robot Base - Icarus

    New Robot Base - Icarus By Evan, Justin, Aaron, and Ethan

    Task: Build the base for the new robot

    Since BigWheel was never intended to be a competition robot, we decided to build an entire new robot based off of it. This means that the base plate of the robot is going to have to be the most accurate part of the robot since everything after that has to be built upon it. To do this, we started out by measuring the base of our original robot, then squaring the whole thing out, making sure it was uniform across the base, down to 1/32". The inner slot that houses the superman lever was done down to 1/16" because it’s precision was not as important; it houses the Superman arm's wheels.

    We cut and trimmed the basic platform using the table saw and clipped some of the thinner excess polycarb off with flush cutters. Once the base was cut to size, we moved onto the bends. The bends were measured exactly where they are on the outside of the current robot. To make precise cuts, we took a trip to the Dallas Makerspace. There, we used the sheet bender to bend our 1/8" polycarbonate which makes up the base, into shape. The walls of the base are then going to be connected to square aluminum piping that has been ripped in half to create the outer wall.

    The task of holding the sides together will be done by two 3D printed parts that will house the LED strip that goes around the outside of the robot (used to communicate to the driver which mode we are in). This base will be much more precise than our previous chassis, making it more reliable as well. Finally, the new base will have more mounting points than before, allowing for greater modularity. The old robot will be a sparring partner for driver practice. The level of craftsmanship that has gone into this baseplate is industrial grade, we have done something comparable in precision and accuracy to any product meant to be mass produced. We can only hope that our final robot works as well as it's intended.

    Next Steps

    To have a fully supported base, we need to add the framing brackets and the wheels before it can be considered a wrap on the base section of the robot.

    Finishing Icarus' Base

    Finishing Icarus' Base By Evan, Aaron, and Ethan

    Task: Perform the final steps to complete Icarus' base

    Since we finished the polycarb base, our robot went through some major changes. We last left our robot in the post-bend stage, just a piece of polycarbonate. The first thing we did was to square the whole robot with side brackets. These cleanly ripped aluminum C channel side brackets now serve as the highly accurate frame of our robot, which has been measured down the millimeter for the highest level of precision yet.

    After creating the side brackets, it was time to give them the right holes in all the right places. The holes for the rod we use as our drive shaft were drilled in the side brackets, exactly the same on either side, as were the holes for the points of attachment on either side of the robot, connecting the base to the brackets. The front bracket was cut to size and placed on the robot after the REV rail we use as an attachment point for the elbow joint was placed. Then we put the 3D printed brackets onto the REV rails that make up the back end of the frame of the robot, running the bar that became the axle for the wheels. If you want to see just how far we’ve come, you can look back at the article that Arjun and Karina wrote about building the first version of the robot over the summer. The amount of improvement is large and part of the journey. Everything on the robot is done for a reason, be it stability, weight, or efficiency. This time around we’ve significantly reduced the number of extra things on the robot, and simplified it as much as we possibly can.

    Next Steps

    The next step is going to be told in an upcoming article that will describe the process of building the arm mount. If this robot is going to be on the field and compete, it needs the elbow joint to be constructed, so that’s next on the evolution of the new robot.

    New Elbow

    New Elbow By Justin

    Task: Design an elbow for bigwheel that we can 3d print

    To speed up the build process of the new robot, we made a 3D printable part of the elbow joint. The design simplifies the complex assembly of the elbow mounting point and makes it a single printable part. The old elbow contains many different parts that would need to be spaced precisely in order for the gears to mesh properly, while the new print allows us to stay consistent with our measurements when building the new robot. The part contains motor mounting holes, as well as a socket to support the weight of the motor. There is also a place to put the bearing that the lift system rotates on.

    This had to be spaced properly so we calculated the exact distance by using the number of teeth and module of the gear to find the diameter. The part also has two places to attach it to a REV rail, which allows us to secure the elbow to the chassis. The spacing between the bottom REV rail socket and the bearing hole is spaced so that the gear that aligns with the bearing is flush with the front plane of the robot to stay within 18 inches. The new bearing hole is also higher up than the hole on the old robot, which gives us more extension when intaking or depositing minerals.

    Next Steps

    We need to attach the new mounts and test how the new height of the elbow mounting point affects our balance and latching.

    Constructing Icarus' Elbow

    Constructing Icarus' Elbow By Evan, Aaron, and Ethan

    Task: Build the elbow for intake

    In the last Icarus' blog post, it was just getting the basic flat, support frame of the robot. The next step in the construction of Icarus' is the elbow joint that holds the intake. This time around, we simplified everything significantly as compared to BigWheel, reducing the excessive aluminum parts to two 3D printed parts. We attached these to the REV rail that runs across the front of the robot with two smaller REV rail parts we custom cut to fit the size of the 3D part. Then, we inserted the motors that each of them requires. Here we are using the same REV HD motors we used for our elbow on the last robot since they worked quite well. After inserting these, we went about supporting the elbow frame, which was done with two REV rails attached to the robot from the top of the 3D printed piece.

    These were attached at a 30-degree angle and anchored to the robot behind the two drive motors we use for the wheels. Once both of these were secured, we began assembling the arm. The arm itself has remained mostly the same, consisting of two linear slides on either side for a grand total of four, extra smooth slides. We drilled out the correct holes on all of the arm pieces, created four custom metal parts for the slides, which took a while on the bandsaw, and then assembled the bottom slide of the arm. Three holes were drilled out in four REV 86 toothed gears, which work as the mounting point of the linear slides. Once these were attached, we attached all the other necessary parts for the arm and life on the elbow joint’s 6mm hex axle that protrudes from a ½ inch hex axle set on two bearing with ½ inch hex inlay for an insanely smooth rotation. After all the necessary hardware was set in place, we put a redesigned version of our 3D printed gear keepers on to keep the distance between the motor shaft and the rotating shaft the same, and the gears firmly interlocked. During the time frame of this article, the new superman lifting lever was put into place.

    Next Steps

    The next step in the saga of the robot is the hook and the new intake, which will be seen in upcoming articles. As well, if the robot is to score at worlds, we need to construct the arm lift for the intake and then the intake itself, which will be redesigned and improved. Also, some wiring would be nice.

    Icarus' Superman Arm

    Icarus' Superman Arm By Evan, Aaron, and Ethan

    Task: Design and install a lifting arm for Icarus

    At the same time as the elbow joint was being done (which can be found in the article "Constructing Icarus' Elbow”) the Superman lift was being installed in the back half of the robot. The old superman system was difficult to install, but we designed it to be slightly easier. Mounting brackets were already pre-set in the robot so we didn’t have to disassemble half of the robot to be able to set screws into the extrusion rail. Bearings were inserted into the brackets, and the process of sliding all of the needed parts onto the rails began. First was the outside shaft collar, which holds the 6mm hex shafts in place. Then was the first interior shaft collar, which kept the internals in place. Then the first of the gearkeepers was put on, followed by a spacer meant to separate the gearkeeper’s bearing from being popped out by the gears on the Superman arm. Then came the actual Superman arm, which is one centimeter longer than our original arm, hopefully allowing more lift.

    It’s made of three 125 toothed gears from REV, with the center one’s ridges drilled out, a REV rail sized chunk sawed to insert our actual lever bar, and 3D printed spacers separating each of the gears around the outside which have all been bolted together. On the end of the bar is a 3D printed holder for the four omni-wheels we’ve positioned there, which are all set with bearings for smooth motion. Once this was slotted onto the 6mm hex rail we added one more spacer, the other gearkeeper, then the final interior shaft collar. It was put through the other bearing and bracket on the other side and finally closed off with a lost final shaft collar on the outside.

    After we got the arm in, we moved on to the driving 6mm hex shaft. Since this one was a lot longer and was hard to fit into the space provided, it was aligned in a way that it could slip through the slots of the wheels as we pushed it into place. We first put a REV core hex motor and a shaft collar that would work as the outside clamp. Then we put it into the bearing on the bracket and pushed it through. A shaft collar was placed, and then we attached the other end of the gearkeepers on. It was tight like we wanted it to be, but it didn’t make our builder lives easy. We put on a spacer to keep it in line with the Superman arm and then we put on the drive gears, three 15 tooth gears with the center one's sides cut off to mimic the Superman gears on the other side. After we put that in, we put another spacer and then the other side’s gearkeeper. This is where the struggle came. Since the gearkeepers keep the gears together exactly the distance from the center of the radius of the 15 toothed gear to the center of the 125 toothed gear, it was a very tricky squeeze to get it attached. After we managed to get it one, we put another shaft collar on and put it through the bearing on the other side. We slid on one last shaft collar on the outside, and ended the shaft with another REV core hex motor. That capped the entire subsystem off, and all that’s left is it to be wired.

    This system differentiates us from other teams - our robot is able to deposit through a lever arm that rotates the robot itself, adding an additional degree of sophistication and mobility to the robot.

    Next Steps

    The subsystem needs to be completely wired and tested before it's approved for the final robot.

    Reverse Articulations

    Reverse Articulations By Abhi

    Task: Summary of Icarus Movements

    In post E-116, I showed all the big wheel articulations. As we shifted our robot to Icarus, we decided to change to a new set of articulations as they would work better to maintain the center of gravity of our robot. Once again, we made 5 major deployment modes. Each articulation is necessary to maintain the robot's center of gravity as its mode of operation shifts.

    The position seen above is called "safe drive". During normal match play, our drivers can go to this position to navigate the field quickly and with the arm out of the way. In addition, we use this articulation as we approach the lander to deposit.

    When the driver control period starts, we normally navigate to the crater then enter the intake position shown above. From this position, we can safely pick up minerals from the crater. Note that there are two articulations shown here. These show the intake position both contracted and extended during intake.

    During the end game, we enter a latchable position where our hook can easily slide into the latch. After hooked on, our robot can slightly lift itself off the ground to hook. This is the same articulation as before.

    At the beginning of the match, we can completely close the arm and superman to fit in sizing cube and latch on the lander. This is the same articulation as before.

    These articulations were integrated into our control loop just as before. This allowed smooth integration

    Next Steps

    As the final build of Icarus is completed, we can test these articulations and their implications.

    Icarus' Arms

    Icarus' Arms By Evan, Aaron, and Ethan

    Task: Install intake arms

    Since the last post, in which we installed the Superman Arm, we've installed the second stage of the linear lift and the belt drive that accompanies it. We began by drilling two holes in the linear slides that were exactly the space between the holes on the carriages for the linear slides using a drilling template we printed on the Tazbot printer. We did this to two of our linear slides, and then attached them. We realized that they were too long and sticking out of the 18x18x18 sizing box, so we detached them and cut off a centimeter from the top and ground off the edges. They were reattached successfully, and the 3D mounts for the belt system were installed at the same time since they use the same point of attachment as the linear slides.

    Those custom pieces that were mentioned in the Joint Operation article were now utilized, attaching to the top of the first linear slide and to the carriage of the second linear slide. These parts are used for the attachment of the pulley bearings that the belt drive relies on to function. We installed these pieces rather easily but struggled on some of the tighter fits that were done to reduce wiggling in the arms, a problem that the last robot had. The next thing we added was the physical belt which drives our lift. The belt was tied off on the final carriage on the second linear slide on either side. The next step was to create the mounting for the motors that would drive the lift. To do this we set up a REV rail under each of the elbow motors, and then topped it off with another rev rail that we connected to the elbow frame supports that run from the front to the back of the robot. Then we mounted the motors, two Orbital 20 andymark motors, which at first didn't fit. The issue was that there was no way to mount them close enough for a belt to be put in place with the current gear keepers we had on the robot. They were attached, and then the motors were mounted, and the belts were put on. The lift has the same ratio as last time, which is further explored in the article Bigwheel Upgrades. The whole system is much more cleaned up and simplified, and generally looks a lot better.

    Next Steps

    The next challenge for us is going to be making the hook, attaching said hook, and redesigning the intake in time for effective driver practice.

    Wiring Icarus

    Wiring Icarus By Jose, Abhi, Evan, and Aaron

    Task: Wire Icarus to be functional and move utilizing code

    With the construction of Icarus nearing completion we need to start connecting wires from the motors and servos to the REV Expansion Hubs before it becomes impossible to do so.

    • As soon as the expansion hub were placed on the chassis, servo wire extenders were connected before anything blocked us from doing so
    • We used custom sized wires to avoid a mess of wires that were way too long
    • We connected all the motors and servos in the same configuration as we had on BigWheel to keep everything consistent and make coding Icarus easier

    Despite our preemptive measure we encountered several problems when testing Icarus using tele-op control:

    • The polarities on the wires were reversed and this couldn't be fixed in code as the encoder values would be affected by this
    • There was a lot more lag than usual on Icarus, this affected the intake arm as its movement is time-based
    • The speed of the wheels were a lot faster now that we are using a different gear ratio and motor, however unlike the other problems, this can be fixed in code

    Next Steps

    We need to reverse the polarities on all the motor cables and try the fix the lag and speed issue with code.

    Intake Flappers

    Intake Flappers By Jose, Evan, and Abhi

    Task: Design and test intake flappers to speed up mineral intake

    Due to our new intake articulation involving the superman wheel the ice cube tray intake is slightly too elevated to intake minerals. To fix this we designed small flappers out of ninja flex(the Iron Reign way) to help the intake reach further. Tests prove this intake to be quicker than the ice cube tray alone and it should suffice for the UIL State championship tommorow.

    Next Steps

    We will compete at UIL and see if the new intake works

    New Superman Arm

    New Superman Arm By Ethan and Evan

    Task: Redesign the Superman arm to be more robust for Worlds

    In posts E-116, we found that we were putting pressure on the individual teeth of the Superman gears on the order of mPa. We designed gearkeepers to ensure that the gears would interlock and reduce pressure, and these worked for awhile. However, under tournament pressures at UIL, the teeth on the smaller gears broke entirely - between the teeth that composed the gearing-up portion, at the beginning we had 45. At the end, we had 15 teeth.

    This necessitated a total redesign. Upon coming back from UIL, we created a new version of Superman with metal Tetrix gears with a 3:1 ratio - the aluminum Tetrix uses has proven much tougher in the past. To compensate for the reduction in gear ratio, we removed the old Core Hex Motors and replaced them an NeverRest+BaneBots 104:1 motor+gearbox combination. Coming off the bat, the NeverRest outputs .17 N*m, and with the gearbox, it outputs .17*104=17.68 N*m. With the 3:1 gear ratio, it outputs 53 N*m, matching the previous Superman arm while increasing tooth durability.

    This new Superman arm will allow us to rotate the entire body of our robot around the axis of its wheels, allowing us to reach the lander without difficulty and ensure redundancy on the robot. The Superman arm is the centerpiece of our robot; it allows us to utilize Balancing, Center of Gravity Calculations, and Articulations in a truly innovative way.

    Next Steps

    We need to test the arm to make sure no additional stripping occurs.

    Intake Update

    Intake Update By Ethan

    Task: Custom design an intake to improve intake times

    In testing, we found that the intake didn't perform adequately - the balls would slide back out in the inverse articulations. So, we designed attachments for the corn-cob intake out of ninjaflex, figuring that small tabs would hold the minerals in better. It failed - they were too compliant - but we found it was much easier to intake minerals than before due to the high coefficient of friction.

    So, we decided that the corncob base was the issue. We designed a circle with the diameter of the previous corncob aligners and attached thicker tabs on the outside, creating the stl seen above. When tested, this was much less compliant than the previous beater bar, which served to make intake easier. In addition, the combination of reinforced tabs and ninjaflex prevented the minerals from falling out of the intake through increased coefficient of friction.

    Next Steps

    We plan to reattach this to the robot to do driver practice.

    Machining Gears for Superman

    Machining Gears for Superman By Ethan and Justin

    Task: Machine replacement gears for Superman

    Shortly after creating the new Tetrix gear system, we got a response from one of the CNC shops we'd reached out to, offering to machine the 15 and 125-tooth REV gears from the STEP files. So, we took the Superman system off of our old robot, BigWheel, and sent some of the broken 15-tooth gears from UIL.

    In response, the shop sent us the new gears the next day, with added modifications for mounting the gears onto REV extrusion. These gears will make the arm much stronger, making it more robust and able to withstand the shear pressure on the teeth.

    Next Steps

    We need to mount the gears and test them to ensure stability.

    Ninja Flex Intake V2

    Ninja Flex Intake V2 By Jose, BenB, Karina, Evan, Abhi, Ethan, Charlotte, and Aaron

    Task: Design, implement, and test a newer version of the ninja flex intake

    The new ninja flex intake is good, but it has room for improvement. One issue is that it is too big and minerals have some problems entering the intake tray, Another issue is that the spacing of intake gears is too much and cuases minerals to be intaked slower. We fixed this by using smaller intake gears and using six of them instead of five. After replacing them we could test the new and improved intake. Results showed a much faster intake speed with an average intake time of 1-2 seconds. This was a major improvement and most likely the intake's final iteration.

    Next Steps

    Now with a finished intake we can drive test to see its functionality in a real match.