1672 Robo-T-Birds 2023 Build Thread

The Robo-T-Birds are excited to join the #openalliance in 2023! We’re joining for greater commitment keeping up with our build logs and to share our ideas beyond just our team.

Team Links

2023 Competitions

  • Mount Olive (03/10–03/12)
  • Warren Hills (03/24–03/26)
  • Montgomery (03/31–04/02)
  • FMA District Championship (04/05–04/08) (hopefully!)

Team History
While the Robo-T-Birds were founded in 2005, there was a near-total mentor and student turnover in 2017 which made the team effectively re-rookie for the 2018 season. Now, in the sixth season since then, we’ve built back and are continually working to improve the team.

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A Last-Minute Offseason Recap
The Fall 2022 offseason went very well, a marked improvement from previous ones. We ran a twice-weekly meeting schedule. Most meetings were optional, with a few mandatory ones for organization-/safety-critical stuff to get done.

  • Mechanical
    • Trained members on tool use and safety
    • Finished mecanum chassis started in Spring 2022
    • Made simple mechanisms & pneumatics on an old kitbot chassis to practice common tasks
  • Programming
    • Trained members on Java and FRC programming
    • Set up Photonvision with a Beelink PC for AprilTags in 2023
  • Outreach
    • Showed off the robot at the town fair, school club fair, & school parent night
    • Ran an outreach event for middle schoolers to interact with the various aspects of robotics and see what they might do if they join

2023 Build & Competition Goals

  • Get to district championships again
  • “Bus-proof” the team and ensure greater distribution of skills
  • Build a robot with “less duct tape” than 2022 for greater reliability at competition
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Late Kickoff Recap

We had a chill kickoff this year. After the livestream and lunch (with a generous pizza donation from SQ Pizza) we split into small groups to read the manual and think about mechanisms. Some team members went into the side rooms to brainstorm and draw up potential designs on the whiteboards. Notable initial ideas included:

  • Robot inspired by Robonauts’ 2018 robot with a 1dof arm and over-the-bumper floor pickup
  • Mecanum chassis for sideways movement for easier automatic gamepiece scoring
  • A pneumatic “pincher” intake and a 2018-esque compliant intake

Early Week 1

Chassis subteam:

  • After a couple discussions [1] [2] and team discussions about mecanum, decided to build a normal tank kitbot chassis for higher traction on the field and charge station
  • Assembly began immediately as chassis team members split off from major mechanism brainstorming
  • Magnetic shafts with encoder pins were salvaged from the 2022 robot and everything except wheels and outer plates was fully assembled by Day 4

Mechanical subteam:

  • The first meeting, broke off into side rooms to brainstorm ideas for arms and end effectors
  • Limited design decisions down to 2 options with hinge mechanism or up and down crane system
  • Decided that this year’s game is software- and strategy-heavy, which means that mechanicals design should be as simple and efficient as possible to maximize the time programmers and drivers spend with the robot
  • The goal is to get the scoring of cones and cube as precise as possible with just the push of a button
  • To further simplify our design, we chose to skip L3 and focus on L1 and L2 scoring
  • In our next couple meetings, we started to brainstorm and prototype intakes (shoutout to 7461 and 1339 for their fantastic designs!)
  • Continued to disassemble our 2022 robot, Swiss

Programming subteam:

  • Updated all our programming laptops to 2023 software
  • Installed PhotonVision on all laptops to use with our Beelink Mini PC (nicknamed “Greggy”)
  • Purchased OV9281 camera for better vision performance
  • Reviewed fundamentals of Java programming
  • Introduced autonomous code and practiced with our test chassis-only bot (nicknamed “Gregory”)
  • Started to do power draw calculations and an electrical budget

Brainstorming whiteboards!!!

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Week 2 Recap

Chassis Challenges

While we finished the chassis by the end of Week 1, we discovered early Week 2 that the chassis was warped corner-to-corner and wobbled back and forth. We suspected the base plate, which was reused from our 2022 robot, so we detached it, but the chassis still had issues. In the end, we had to almost fully disassemble our chassis as the churros were installed poorly and pulled the chassis into a warp.

Our chassis challenges didn’t stop there. The Toughbox gearboxes on the two sides of the chassis were not performing equally. It took forever to diagnose, but we determined that it was due to assembly error as we had printed the AM14U5 instructions off the Andymark website in advance, but we got an older version. The new T23 version has an extra spacer in the gearboxes, which we had missed, causing worsened gearbox performance on the side made following the printed instructions (rather than the new version, which came in the box and was posted on the Andymark site right after we’d already printed ours out).

Intake Iteration

By the middle of Week 2, we had Identified three possible intake arm/claw mechanisms:

  • Pneumatically actuated claw with cube and cone settings

  • Rack and pinion or pneumatic “crush” arm

  • Compliance wheel roller intake (inspired by 1339)

Each mechanical officer claimed one of these ideas and began prototyping. Prototyping was done in a couple days and we compared the designs:

  • The claw design did not hold onto any of the game pieces really well, and the spacing was poor

  • The crush arm design was discarded after difficulty designing two separate compressions

  • The compliance wheel roller intake worked great, with separate spacing for cubes and cones

We then considered whether we wanted three collinear axles for cube/cone spacing or whether two sets of two axles stacked vertically would be more effective. We eventually decided to go with the stacked intake since it needed less precision to pick up game pieces and would be easier to program since the game pieces would be held at more similar distances relative to the pivot point.

Arm Assembly

After continued math on the whiteboards, we determined that we needed a second stage for the elevator we are using as our arm and found the height that our pulley would need to be at to work well while keeping our robot’s center of gravity lower. Fortunately we had already ordered a second stage elevator kit from Thriftybot and enough Max tube from REV to make it work. We finished elevator design in the middle of Week 2 and cut our first metal of the season on Thursday. Most of the metal was cut by Saturday and assembly of final robot mechanisms has begun! The pivot point for the elevator remains an unsolved problem, but a ½" or ¾" dead axle seems to be a promising solution.

Programming Progress

The programming team continued their work on PhotonVision and preparation for autonomous programming.

@EmerqldWither had the programming team split roles. Some programmers calibrated PhotonVision to work optimally with the OV9281 and Lifecam, others were working on autonomous code practice. This year we are using PathPlanner for autonomous routines and moving forward with the new Commands framework for writing autonomous and teleop commands. Later in the week, the whole programming team came back together to connect our Beelink mini pc (“Greggy”) to our programming chassis (“Gregory”) with our new network switch (“Greg”) to make a robot with vision capabilities for programming practice, known as “Greg³”.

In addition to actually programming, we also set up Git and GitHub for the new year and pushed our 2023 robot code.

Electronics-wise, we gathered all the electronics that we needed for our 2023 robot and soldered barrel jacks and higher-gauge wires to the regulators we purchased to power our Beelink mini pc and our network switch. We also put Anderson powerpoles on all our NEOs and Spark MAXes to get them ready for assembly on the robot as soon as the chassis is back together.

Week 3 Recap

This week was a calmer week, as subteams continued work on their existing projects with the goal of finishing the robot earlier than we did in 2022 and 2020. As an aside, I really oughta work these as the week progresses, because summarizing feels like a rather monumental task (and it’s harder to get pictures and videos after the fact too). Getting these out late is a big feelsbad moment.

Intake Improvement

Early Week 3, we got the bearing-hole MAXTube from REV and quickly started testing it to see if it would be viable to use instead of drilling our own bearing holes in plain 2x1 tube. We messed around with it a bunch and soon found a new design using a mix of stealth and compliance wheels to pick up both cubes and cones with the exact same mechanism, reducing the mechanical complexity of the intake—our old intake designs used either three or four axles with varied spacing, whereas the new design only uses two. The new design consistently picks up cubes and cones almost immediately after making contact, a huge improvement over our intakes in 2022 and 2020.

PhotonVision Practice

Week 3, we recalibrated our cameras and started integrating PhotonVision with robot code on the programmers’ testing robot. We first gave Gregory (the testing robot) a simple AprilTag-following command and then upgraded it to use PID control. By the end of the week, Gregory was following @EmerqldWither around using an AprilTag jury-rigged to his leg.

Gearbox Grief

A major issue we encountered this week was the gearboxes we would use on the new robot. We initially wanted to use MaxPlanetary gearboxes since we are using NEOs this year, but the stock issues at REV messed up those plans. Many of our mechanisms were designed to be geared at 5:1, which made the lack of 5:1 cartridges especially unfortunate. Due to this, we fell back on VersaPlanetary gearboxes we had around already instead of using CIM Sport gearboxes or switching gear ratios.

The VersaPlanetary gearboxes were… an adventure. Three entire days of our engineering notebook included “gearbox problems” as we had to first disassemble our old gearboxes (some of which were mislabeled and thus necessitated looking at the gears to find the ratios) and then assemble them with our NEOs (whose shafts had to be cut). However, we had to disassemble and reassemble them several times to diagnose mysterious ticking noises or variations in pitch we found when testing the gearboxes running with the actual motors.

Elevator Endeavors

Our elevator assembly went well, with the exception of a few missing parts from Thriftybot causing a slight delay. Luckily, after receiving the missing parts, the motors/gearboxes and the elevator carriage were both ready, which made the elevator almost get finished by the start of Week 4.

Official Organization

We made a little rack for our masking and electrical tapes!

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I can see how the cone control is pretty solid - how does the release of the cubes work out? I’m also curious how intelligent the driver/code has to be when picking up cubes - it looks like it’s a problem that could be solved by current limits, but maybe that’s just intelligent operators on the prototype?

The drill tests worked really well with the cubes. We’ve yet to test the NEO 550’s on it properly but I’m sure that it’ll be tunable to both intake and release well.

Another late post… oops. I didn’t even put any alliteration in section headings… but here’s what we did Week 4! In general, we feel like we’re ahead of schedule compared to prior seasons, which is a good sign.

Programming

The programming team continued learning Java to get ready for programming the robot soon. They also reconfigured PhotonVision on the test chassis with better camera positioning and finally got pose recognition working well.

Elevator

Early Week 4 we determined that we need to use two motors to pivot the elevator, one attached above and one attached below the elevator, connected to the elevator with ropes. The elevator itself was completed in the middle of the week.

Intake

We mounted NEO 550s and Spark MAXes on our intake, tested it, and… it didn’t work! After the really successful series of drill tests, the failure of the 550’s to intake the cubes was quite surprising. We checked the math, finally finding a fatal flaw: we had missed a conversion from inch-pounds to foot-pounds, meaning our math was off by a factor of 12. We had to disassemble the intake and reassemble it with 20:1 gearboxes in place of the 5:1 gearboxes we had earlier. The new intakes were tested today and the higher gear ratio proved successful.

Field Elements

After our chassis misadventures, the chassis / field elements team finally got to work on field elements and started the charge station. By the end of the week, the charge station was finished (minus polycarb surfacing) and we had tested it with our programming test robot, Gregory.

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:rotating_light:BREAKING NEWS :rotating_light:

Today, 34 days after Kickoff, we mounted the first part of robot superstructure on the chassis! It’s finally all coming together! Hopefully we get our elevator pivots and winches done in the next few meetings and then it’s mostly software and driving time till our first competition.

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