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Iron Reign

Welcome to Iron Reign at Dallas ISD's Science and Engineering Magnet

Articles by section: engineering

Finishing the Chassis

29 Apr 2018

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

02 Jun 2018

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

09 Jun 2018

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.

Position Tracking

18 Jul 2018

Position Tracking By Abhi

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

Throughout the Relic Recovery season, we have had many issues with the autonomous being inaccurate simply because the scoring was dependent on perfectly aligning the robot on the balancing stone. This was prone to many issues as evidenced by numerous matches in which our autonomous failed. Thus far, we had relied on the encoders on the mecanum chassis to input distances and such. Though this worked to a significant degree, the bot was still prone to loss from drift and running into the glyph pit. We don't know if glyphs will be reused or not but we definitely needed a better tracking mechanism on the field to be more efficient.

After some investigation online and discussing with other teams, I thought about a way to make a tracker. For the sake of testing, we built a small chassis with two perpendicular REV rails. Then, with the help of new trainees for Iron Reign, we attached two omni wheels on opposite sides of the chassis, as seen in the image above. To this, we added axle encoders to track the movement of the omni wheels.

The reason the axles of these omnis was not dependent of any motors was because we wanted to avoid any error from the motors themselves. By making the omni wheels free spinning, no matter what the encoder reads on the robot, the omni wheels will always move whichever direction the robot is moving. Therefore, the omni wheels will generally give a more accurate reading of position.

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.

Technicbots Chassis Project - July Meeting

22 Jul 2018

Technicbots 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 Technicbots' 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.

Replay Autonomous

28 Jul 2018

Replay Autonomous By Arjun

Task: Design a program to record and replay a driver run

One of the difficulties in writing an autonomous program is the long development cycle. We have to unplug the robot controller, plug it into a computer, make a few changes to the code, recompile and download the code, and then retest our program. All this must be done over and over again, until the autonomous is perfected. Each autonomous takes ~4 hours to write and tune. Over the entire season, we spend over 40 hours working on autonomous programs.

One possible solution for this is to record a driver running through the autonomous, and then replay it. I used this solution on my previous robotics team. Since we had no access to a field, we had to write our entire autonomous at a competition. After some brainstorming, we decided to write a program to record our driver as he ran through our autonomous routine and then execute it during a match. It worked very well, and got us a few extra points each match.

Using this program, writing an autonomous program is reduced to a matter of minutes. We just need to run through our autonomous routine a few times until weare happy with it, and then take the data from the console and paste it into our program. Then we recompile the program and run it.

There are two parts to our replay program. One part (a Tele-op Opmode) records the driver's motions and outputs it into the Android console. The next part (an Autonomous Opmode) reads in that data, and turns it into a working autonomous program.

Next Steps

Our current replay program requires one recompilation. While it is very quick, one possible next step is to save the autonomous data straight into the phone's internal memory, so that we do not have to recompile the program. This could further reduce the time required to create an autonomous.

One more next step could be a way to easily edit the autonomous. The output data is just a big list of numbers, and it is very difficult to edit it. If we need to tune the autonomous due to wear and tear on the robot, it is difficult to do so without rerecording. If we can figure out a mechanism for editing the generated autonomous, we can further reduce the time we spend creating autonomous programs.

C.A.R.T. Bot Summer Project

12 Aug 2018

C.A.R.T. Bot Summer Project By Evan, Aaron, 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

18 Aug 2018

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. First, Kenna and I sat and cried.

Then we started to diagnose the problem. We noticed that the old tetrix 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 tetrix 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 cabels 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.

Relic Recovery Brainstorming & Initial Thoughts

08 Sep 2018

Relic Recovery 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

09 Sep 2018

Testing Intakes By Ethan, Evan, Aaron, and Freshmen as to be determined

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.

Rover Ruckus Strategy

10 Sep 2018

Rover Ruckus Strategy By Ethan, Kenna, Charlotte, Evan, Abhi, Justin, Karina, and Aaron

Task: Determine the best Rover Ruckus strategies

Challenge Game Timing Points Level of Difficulty (1 - 3 [hard]) Priority Idea
Landing Autonomous 30 2 Medium
Claiming Autonomous 15 1 High
Parking Autonomous 10 1 High
Sampling Autonomous 25 2 Medium
Latching End Game 50 3 High
Robot in Crater End Game 15/25 1 High
Mining [Depot] Tele-Op 2 per item 1 High
Mining [Cargo] Tele-Op 5 per item 2 High

Brainstorming Two - Enter the Void

15 Sep 2018

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

22 Sep 2018

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.

Contact Us

E-Mail: ironreignrobotics@gmail.com Website: In the address bar