Sunday, January 8, 2023

Kickoff

Priority List

We completed our initial priority list of tasks for the 2023 game. 



Cones from the shelf or the floor.

From what we have seen, we are currently a lot lower ground pick of cones than many other teams. Here are a few reasons that we discussed today.


  1. The cones can’t easily roll much further than the wall when dropped onto the floor from the loading stations, so you don’t have much of a cycle distance advantage over taking it off of the shelf.

  2. Intaking the cones from the various orientations and positions against the walls will be very difficult. We don’t believe it will be faster than loading from the known positions on the shelf, especially with the possibility of vision-guided aiming at the loading station. 

  3. The Human Player shelf is just a bit higher than the middle cone node, so you don’t need to raise or lower it to be able to place it on the midsection. And for the top, you only have to raise it about a foot and extend it about a foot more than the mid. Much easier than also needing to reach the floor with your cone mechanism.

  4. You can have a specific cube(ball) intake on the ground level and don’t have to potentially compromise your robot's ability to intake cubes(balls) also to pick up cones rapidly.

  5. 15 scoring locations out of 27 can be cubes which is more than half.

  6. Each alliance has 27 cones, so if you drop one, you can always return and get another to fill the 12 required spots.

  7. Any dropped cones while attempting to score on a mid or top row will land in the bottom row. If you are strategic about when you score the bottom row, your mistakes may still count for points.


Potential Alliances composition at Districts and Worlds



Cube Intake and Launching Prototype


Robot Inspiration

  • 33 in 2012 - Stinger and other 2012 team’s bridge balance aids

  • 1678 in 2019 - Double robot lift for the end game (wouldn’t need to climb)

  • 148 - 2011 - 4 Bar Arm - Arms are potentially useful in this game

  • 1684 - 2019 - Separate intake from elevator scoring mechanism. Doing this for the cubes(balls) will give you a wider intake for picking up the cubes(balls) from the floor.

  • Tilted/Angled Elevators from 2018 - 2056, 1731, and a few other teams had slightly tilted elevators that let them reach out of the frame while extending up.


Game Comparisons

  • Logomotion - 2011 - tic tac toe near side

    • Driver training will be similar.

  • Rebound Rumble - 2012 - End Game

    • Balancing on the bridge

  • Steamworks - 2017 - Cycles and non-symmetric field

    • Autonomous and cycles will be different depending on which alliance you are.

  • DDSPBTBC - 2019 - Multi-Game Piece

    • Cubes roll like cargo, and cones behave like hatch panels.

  • Power Play (FTC) - 2022

    • Picking up Cones

Friday, January 6, 2023

Fall Elevator Design

We also designed an elevator during the fall, like many many teams. Ours wasn’t designed specifically to be a model of how we could build a competition elevator in 2023 if needed. It was designed to experiment with a few different elevator ideas and be a useful training tool for robot assembly.

Onshape Link


This elevator can either be run in a cascade setup or, as modeled, set up so the first stage motor and the carriage are decoupled and can be controlled independently. This could let you have a starting position with the carriage at the top of the robot or allow for specific over-the-back designs. You can also gear each stage for different speeds/power. You could have a very fast carriage used for most of the scoring and a slower 1st stage used for climbing and some scoring.

The carriage is raised and lowered by a belt running from the bottom to the top of the 1st stage that isn’t modeled in the CAD and powered by a motor on the carriage. This design took some inspiration from 1114-2019 with the sprocket and chain on the front side of the elevator. This design is also inspired by 971-2019’s thin polycarb cable carrier method.

Thursday, January 5, 2023

3D Printed Timing Belts for Prototypes

We experimented with 3d printing 5mm HTD timing belts. 

CAD files

OnShape link to the belt generator we are using to make our belt models: https://cad.onshape.com/documents/0b9fe420322fe41da56645bf/w/76fedf9bfb5b78e06920c37c/e/7f7fe2c94f4c984c8a5860c6


We need to be able to tune the geometry of the belt to allow us to print it correctly and work well with our slicer settings (details below)


Materials

  • TPU 95A: This material was too elastic and stretched too much.

  • PCTPE: This is one of the most promising materials. It’s a nylon and TPU copolymer. It’s flexible but not very elastic. Belts made with this at the correct size could slip due to stretch, but we believe there may be a way to print belts slightly undersized that will stretch to the correct size.

  • TPU-CF: TPU with chopped carbon fiber this material also worked very well.


Slicer Settings

  • This was the important part of making timing belts that worked the way we wanted.

  • The main principle is getting each layer to only be complete loops of filament. In our case, this is 4 total perimeters of 0.6mm thick extrusions. You can adjust the model to help get the correct setup.

  • The top and bottom solid layers are turned off.

  • Avoid Crossing perimeters is turned on to limit stringing

  • The seam position is set to random to avoid a misshapen tooth where the seam may be.

  • This does leave a small hole in the belt, but that didn’t seem to cause a problem with our tests.



Results and Recommendations

  • We printed two belts for our 2022 launcher hood and were able to launch balls well with the printed belts. They do feel looser than the stock-reinforced belts.

  • At the current stage, we are confident we could print a belt for a prototype or test, but we wouldn’t want to use a printed belt on a competition robot in any critical area.

  • The next step is to alter the geometry so that we can easily print a belt with a slightly smaller diameter than a standard belt but with a similar tooth size so that we can account for the stretch built into the printed materials.

Software Organization Update for 2023

One of our larger projects this fall was creating a plan to restructure our software to make it easier for more members to be involved in software development. 

The main idea was to make everything a system (subsystem), so auton, pilotGamepad, operatorGamepad, vision, etc., are all considered systems in our structure. Each of the systems has its own folder, its own config class for constants, and its own commands class (and possibly a folder for full command classes). We attempted to split more things out of the default subsystem class so they can be updated and version controlled separately. An example of this is having a separate folder for trajectories/path planning outside of auton or swerve.



Some other things that have changed or been added

  • Created SpectrumLib in its own GitHub library and include it in our project using jitpack.

  • LED Animation system using the WPILib FPGA LED driver

  • Incorporating AdvantageKit

  • Spotless auto-formatting

  • Template Mechanism classes for rollers (intakes, shooters), angle mechanisms (arms), and linear mechanisms (elevators)


2023 Software Changes Notes these aren’t all fully implemented or detailed here, but this is where we were keeping notes as we went through the process of overhauling our code structure this fall.


Our Flash-2023 Repo is the code for our swerve test platform that uses the new structure. So far, it has been working well, but without a full season, we don’t know what bugs will turn up due to these changes. 


Start of the 2023 Season: X-Ray 2023

Spectrum is back for our 12th build blog. Our robot this year will be named “X-Ray 2023”

2023 Spectrum Season Resources


2022 Robot Rules Overview

With many of the robot rules now evergreen, we did a presentation on the rules ahead of the kickoff to give our students a good understanding of the basic rules. This may be a good thing to have your team listen to before Saturday.


Video: https://www.youtube.com/watch?v=6d-DoTdu5wc


OnShape Training

We updated and added to our Design Training Slides. We haven’t gotten a chance to record videos for these, but the slides should be helpful.


  • D3.1 OnShape FRC Robot Organization - 2023: Slides

    • Updated our recommend process to use reference cubes (similar to 1678 and others)

    • Added Variable Library Details

  • D3.5 Part Design Process - Slides

    • It goes over the process of designing a part for our robot and what should be thought about and done in the design.

  • D3.6 FeatureScripts - Slides

    • Links and explains many of the featurescripts that FRC teams can use to speed up their CADing


System Organization

Spectrum has a relatively flat organizational structure. We don’t have any year-round captains or specifically assigned subteams, etc. During the season, we have system leads for hardware and software.  We try to limit it to 5 systems, with each of these systems normally led by 1 or 2 students. Here is how the breakdown normally works.


Hardware

  1. Swerve/Frame/Bumpers/Controls

  2. Game piece mechanism 1 (usually intake)

  3. Game piece mechanism 2 (was ball path in 2022)

  4. Game piece mechanism 3 (was launcher in 2022)

  5. End Game


Software

  1. Swerve/Drive Tuning

  2. Autonomous/Path planning

  3. Vision

  4. Game Pieces Mechanisms

  5. End Game (likely other tasks)


- Spectrum

Wednesday, November 23, 2022

2023 Spectrum FIRST Choice & Voucher Recommendations

The FRC Season is fast approaching, and it's time to start preparing. The priority list window for FIRST Choice round 1 has started, and every team should have their lists submitted by Dec 1st.

Spectrum has prepared a few documents that can help you set up your Priority list and use your Virtual Kit of Parts Vouchers.

1. 2023 FIRST Choice & Voucher Recommendations Guide

This guide has recommendations for your priority list and how to use each voucher. This should be the starting point.

2. 2023 Spectrum recommended FIRST Choice Items

We believe these items will help the majority of FRC teams and explain some of our reasons and how you can use the items. There are lots of FIRST Choice items, and some of the ones not listed on our list may be perfect for your team, so be sure to look through the entire list.

3. 2023 Voucher Sample Checklist

New for this year, we have created a Voucher Checklist Template. Thank you to FRC#1745 for the suggestion. Make a copy of this google spreadsheet so you can check off when you use your voucher codes and keep them in an easy-to-access location. 

Wednesday, March 9, 2022

Dripping Springs District Recap

We are thrilled to be the 2022 Dripping Springs District Winners with 6800 Valor and 5503 Smithville Tiger Trons.

A big thank you to 6800 for picking us to be on your alliance, you all have an awesome team and robot this year. Thank you to 5505 for joining us and being a great alliance member, your driving skill made our alliance so much better. 


Infrared Mechanism Notes from the Event

1. Drivetrain - The SDS MK4i modules worked extremely well, we swapped 5 wheel treads during the event due to wear and cuts/delamination which is better than we experience with the MK3s at the Texas Cup event this past summer. Other than adding grease (we use PTFE) the swerve modules were maintenance-free.

2. Intake - The intake performed very well, the floating roller was able to precisely pick up the cargo we wanted and do so quickly. We have a 3D printed pneumatic cylinder clevis break that we swapped with a metal one but that was honestly to be expected. The belt slipped off the pulley a few times but the design doesn't allow to fully come off so the intake continues to work, we will reprint that pulley slightly wider and possibly increase the flange height to prevent this in the future. 

3. Ball Path - The ball path indexer and feeder rollers were pretty much maintenance free they just worked all competition. We clean all our rollers with simple green between matches to remove hair and dust and that's all we had to do to keep these systems working. 

4. Launcher - We were running a very simple launcher software with two hood positions and wheel velocities one for the tarmac line shot and one for the fender shot. The fender shot worked on the practice field but wasn't working well on the real field so we abanded it and basically ran fixed hood, single velocity the rest of the event. We had one big launcher issue where the belt to the hood came off and destroyed its pulley, so we had to replace it, we also printed some upgraded pulleys at the event (we bring a Prusa mini with us) but never needed to install them. We also discovered after the event one of the printed pulleys on the falcon wore down a lot and should have been replaced at the event but it didn't affect our performance much. 

5. Climber - As expected our climber needed the most help during the event. We identified some issues when we tested the climber with the full robot weight compared to our test chassis (weighs ~85lbs). We were able to install larger (1 1/16") bore cylinders and change the strap path to the spool to fix these issues before the event but there were still some tuning to do. The winch strap wasn't wrapping consistently so we had to disable soft limits to ensure we could reach the rear latches each time and we were tuning the motion magic distance values to automatically unwind and wind the winch, once we got those working Saturday afternoon the climb we relatively consistent and we could high bar as needed. We believe the traversal would have worked as well but we were never in a situation where the extra 5 points were needed and it was never worth risking the RP and in the playoffs, the extra points wouldn't have affected the match outcome. 

6. Controls - we were running a pretty limited software setup for this event. Our autonomous mode was just timed-based driving (using the velocity loop on our swerve drive) and simple command groups for the double ball auto. The launcher was a feedforward + PID loop to a single velocity for the tarmac line shot. Limelight tuning was set up during the field calibration window before the practice matches and needed to be pretty different from our home setup due to lighting and we used the smart target group feature for the first time. Motion Magic was used on the climb to make it easier to control. We didn't have any electrical or controls issues throughout the event.


Scouting/Strategy Notes

We used the new scouting systems designed by 2713, Link. This system worked very well, it doesn't need wifi/internet access and you can collect the data easily. We used amazon fire tablets and a QR code scanner from Amazon.

Our strategy lead posts strategy notes for our drive team before each match, here is an example of what is sent prior to each match.

We are RED 2
4063  3847  8507
■■■■Qual 49■■■■
4734  7521 3834
  • We have 4063, focus on balling out and high climb for 4 rp
  • Expect defense from 3834
  • They have a double mid-climb + 1 low goal scorer

This gives our drive coach enough information to go to the prematch strategy meeting before each match to make a plan for our alliance.

Photos and Videos:

Spectrum Dripping Springs Photos - Dripping Springs teams feel free to use these photos for any team promotion, etc. 

Spectrum 2022 Dripping Springs Match Videos