FRC 7407 2022 Open Alliance Build Thread

I am excited to launch the 2022 Open Alliance build thread for 7407 - Wired Boars!

7407 started in 2019 and unfortunately have only had 1 complete competition season in 2019. I started with the team this fall and we have been busy bees prepping for 2022! A little bit about us:

Our school is Choate Rosemary Hall and we are an independent boarding school in Wallingford, CT. 7407 welcomes students from all over the world, which is pretty cool! The way our team works is pretty unique, as we have a full academic signature program dedicated to FIRST Robotics called the “Advanced Robotics Concentration” or ARC, as we like to call it. Students can apply for ARC after their freshman year at Choate. Right now we have 23 students in ARC, and these students take a variety of FRC-based robotics courses:

  • CS450HO - Robotic Design & Fabrication: I actually got to re-write this course last summer so we are running a fully custom FRC curriculum in this course! This course is intended for students brand new to ARC and focuses on the mechanical aspects of FRC. Students learn how to use CAD software (Onshape) through a FRC-based design challenge. This year I chose the task of designing floor gear intakes from 2017, and the students designed, manufactured and tested their designs in class. Students also learned how to operate all shop equipment (hand tools, power tools, 3D printing) and how to run the CNC routers. Additionally, students used the NASA RAP Guide as a textbook, and there were weekly reading assignments and reflection questions from the book to complete. If you are interested in checking out their final design posters and technical reports you can find those linked below, soon to be posted to our website (currently under construction)

  • CS560HO - Competition Robotics: This course is just as it sounds - time to build the competition robot in class! We have 2 sections during the class day that meet 3 times a week for 1 hour and 10 minutes. This class started after Thanksgiving so we had a few weeks to do additional prep for build season. I really liked this format so I think we will run this in future seasons. Students were able to choose one A project and one B project to focus on. A projects included prototyping cargo and hatch intakes from 2019, fabricating a swerve drive, fabricating an elevator design that was created in 2021, designing and fabricating a pneumatic linkage to attach an existing 2018 cube intake to a swerve drive, finalize swerve drive code and make autonomous pathing routines, write teleop code for an existing tank drive, and creating a 2-stage parametric elevator CAD model in Onshape. We actually fabricated this elevator with our buddies at 2168 and will be sharing the full parametric model and results from building the elevator, and the students who worked on the model will be writing a post about it soon! B projects included technical mentorship of other teams, pit design, various media projects, technical documentation and awards prep, CNC management and scouting systems.

  • CS570HO - Autonomous Robots: This course will go a full overhaul this upcoming summer, but we are doing a mini redesign before we run the course this spring. This course is intended for advanced programmers and students will have already taken our intro to CS courses before this class. All of our coding classes at Choate are in Python so that is the language we are using for FRC code right now. The general idea of this course is to have a variety of FRC drivetrains available to the students (tank drive, swerve, maybe an H-drive?) that they will create various autonomous routines for. I am also thinking of making a project around automating the 2020 ball tunnel as right now there are no sensors and I genuinely have no idea how the students were able to operate it and make it look easy :rofl: I have been asking around for ideas for this course so please reach out if you do! I will be doing a full re-write in summer 2022!

  • Potential Future Course Add - Advanced Robotic Design and Fabrication: Our long-term goal is to add this course to the ARC line-up eventually, with the idea that we would invest in more advanced machining equipment and have the students design more complicated FRC-based mechanisms.

So that covers the academic side of FRC at Choate! But there is always more!

In addition to class time during Competition Robotics, FRC is considered a “sweat sport” at Choate (we love that name) so students get athletic credit during winter term. This means we have afternoon meetings just like sports teams. The afternoon schedule in MTRF 4-6 and W 130-430. We also meet on Sunday’s.

On Sunday’s our club robotics team also meets, as they are currently preparing for their VRC competition on 1/22! We brought VRC Teams back this year as a measure to include more students in robotics on campus as well as recruit students for ARC. Our Sunday team has about 25 members, mostly freshman and sophomores. We also started an FLL program for kids of faculty and staff on campus and ran 1 Discover team, 1 Explore team and 1 Challenge team, about 25 students altogether. Students in ARC and in Sunday club robotics helped mentor the teams this fall. Once their VRC competition is over, I will be working on bringing these students into FRC projects, especially scouting systems, pit design and really anywhere else they can help out.

Many of the students in Sunday club robotics also take our Intro to Robotics 1&2, as these electives are open to all students at Choate, not just ARC students. Intro 1 focuses on VEX V5 based mechanical building challenges for the first half, and then coding challenges for the second half. Students use the VEX V5 Pro coding software so they get some C+±lite exposure and get a general understanding of how robot code works. I am teaching Intro 2 in the spring, and it is more of the same, just more advanced building and coding challenges. I taught Intro 1 in the fall and it was a blast! Like I mentioned before, there are also lots of coding classes at Choate students can take, from intro to more advanced topics in Python.

Unfortunately, classes are virtual at Choate right now until otherwise announced. Thankfully teachers live on campus so we should be able to run parts the students design virtually for prototypes, but I hate that they may not be able to do it all themselves. Kickoff is looking like it will be 100% virtual right now, so check back for virtual kickoff resources! :grimacing:

Later this week we will have links to our social media, GitHub and 2022 Onshape! I am currently working on getting my students going on writing these posts so expect to hear from them soon!

Please reach out with any questions you have about our team, classes or anything else (:


I forgot to add our fall recap video and River Rage recap video as well, in case anyone is interested in seeing our fall offseason in a video format!

River Rage 2021:

Fall Recap 2021:


You always have the best recap videos! :heart:

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Man, this team sounds so cool. How do I join?


Heyyo, my name is Sebastian, and I’m a student member of 7407. We wanted to share our parametric elevator project we completed in the offseason with the FRC community, so we made a short report describing the project. It is linked here and attached as a pdf. The actual Onshape file is linked in the document as well Let me know if you have any questions.

peace out :v:

Parametric Elevator Report: Parametric Elevator Project - Google Docs

If you wanna jump straight to the OnShape link: Onshape


From my student Jackson! Gen z too cool for boomer chief delphi so I will post here for him :rofl:

As you all probably know, this past weekend was Kickoff Weekend. On Saturday, we (Team 7407) began the brainstorming period by first summarizing the most important rules in the 2022 rulebook.

Here is a link to a game summary google doc we made:

A lot of our students wanted to understand the game visually as well so we made a document called “i like looking at pictures frc 2022 RAPID REACT” linked here!

We especially focused on the scoring and tasks the robot could or could not do. On Sunday, we decided what areas of our robot we need to devote the most resources to, and our strategic priorities. After many discussions weighing the pros and cons of all sorts of strategic decisions, we as a team eventually concluded that our primary focus of resources will be as follows:

  1. swerve drive wheelbase system
  2. mid to high to traversal system
  3. floor cargo intake
  4. high/low scoring system

We decided to focus more resources on the rung traversal system than on a scoring system because we would be building the rung traversal system from the ground up with no prior team designs or inspiration. Let me know if you have any thoughts or questions.

We would also like to share our newest dank meme format with all, you are welcome in advance


Against my better judgement, I have decided to upload a mega cringe video from my college days on 190 in 2013. It has big early 2010 energy and my video editing skills have come a long way since :rofl:

We did a cute little pyramid climb though that teams may pull inspiration from for this year’s climbing task. We called it the WOMBO COMBO because we were cringe

Anyways, here you go:

We had two little T-Rex style arms that hooked onto the rung, and then a telescoping arm came out and grabbed the next rung. T-Rex arms released once arm was attached to next stage. Rinse and repeat to level 3! The telescoping arm had actuation ability to move at an angle but I honestly can’t remember what it was. Probably something overcomplicated to be honest LOL, when a piston would likely have done the trick.

Let me know if you have questions!


Ahahaha, love the video Dee! We still have the bits from the climber so a quick thread “hijack” with some more pics and info…

Here’s a photo album with some pictures of the mechanism:

The “T-Rex” arms are single-stage with a piston inside of them - they only come out several inches. The hook at the top is spring loaded. The telescoping arm is driven in both directions with Dyneema cord and is two stages. The telescoping arm also has a pretty cool little Lexan plate with a limit switch that flexes to tell when tension is being pulled onto the cord.

If you’re interested let me know if more/different photos would be advantageous and I’m happy to help.

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thank you sharing! This is so helpful! I totally forgot about the pistons in the T-Rex arms!

Also my CRUD name is T-Rex…it all comes full circle :triumph:


Hi, Dee! I love this FRC concentration class! Actually, we are doing a Robotic which is related to FRC too. I really really hope to have a chance to talk about your FRC-based robotics courses and learn from you, and also would like to see if there are chances for us to cooperate at a school-wide level~


Yes, just replied to your DM! We would love to collaborate!

Week 1 Summary:
Strategy and Design Updates
After hours of discussions involving many team members, we came to some strategy and design conclusions as a team. We began by listing all the subsystems (drivetrain, shooter/indexer, floor intake, and climber) and ranking every functional specification that each subsystem could do on a scale from one to ten (with ten being the most important). We then aggregated each subsystem’s ranked list into a master ranked list. In creating our rankings, we listed everything the robot could do. For example, for the shooter subsystem, we listed everything from storing two cargo (ranked at a ten) all the way down to inbounding cargo from the human player (ranked at a one). Our top five priorities for the design of our robot go as follows: medium bar climb; the ability to store two cargo; touch it, own it, high speed intake system; high bar climb; and a low hub cargo dump.

One of the things we are keeping in mind during the brainstorming and design phase is the center of gravity of our robot. A low center of gravity is better for not getting our robot knocked over during the teleop period. A high center of gravity is better during the traverse period so our robot does not swing into the wall. The key is to find the sweet spot with our center of gravity.

We decided that a mid-height shooter is better than a high-height or a low-height shooter. The main dilemmas here are gauging the defense that our robot will encounter and determining how difficult it will be to get the cargo from our robot to either the upper or lower hub (shooting speed and angle). Keeping in mind that we are using a highly maneuverable swerve drive system, we don’t anticipate defense being overly difficult to evade. Coupled with the possibility of shooting on the move, defense is an issue that can be mitigated more easily than we anticipated. For the intake and the shooter, we should focus on how to compress the ball. We are going to test a metal flywheel versus a rubber flywheel and will brainstorm using a parabolic flywheel in order to get more surface area on the cargo.

Prototyping Updates
We experimented with intake systems this week by attaching velcro to a shaft and rotating the shaft. The velcro attaches to the cargo and drags it towards where we want it.

Manufacturing Updates
This week, our manufacturing team experimented with running our ShopBot by building pieces for the drivetrain. They also made a manual for how to use our Omio so that more team members can use it.

Field Build Updates
We started building a practice field. Not much to say on this topic just yet.

Programming Updates
This week, our programming team did many things. They set up the new swerve drive code. They added grabber code to swervy. They determined our optimal shooter launch angles. Also, they updated the dashboard and wrote a drive command for last year’s practice bot.

Drivetrain Updates & Driver Practice Plan
This week, we began drivers practice for the season. We held evening practice on Tuesday, Wednesday, and Friday with swervy. We are going to hold driver tryouts in the next few weeks.


Open Alliance Post - Week 2

Strategy and Design Updates:
This week, we finished discussing our robot’s layout and began our CAD model. We began our CAD model with 2D Onshape sketches followed by a 3D box layout model that we are using to flesh out our robot. On Sunday, we are planning another CAD-a-thon to get a sizable chunk of our CAD work done and dusted. Work also started this week on a linkage system between the intake and the chassis.

Full Robot Assembly CAD 1.19.2022

Prototyping Updates:
This week, we worked on an adjustable shooter prototype and a very rudimentary adjustable intake prototype. Attached is an image of our adjustable shooter prototype.

Manufacturing & Assembly Updates:
This week, we began manufacturing some pieces for our robot, including some of the tubes for our central tower superstructure and some hooks for our climber/traverse system. The electronics system for our robot is coming along well. On Saturday, we powder-coated pieces for our drivetrain in a beautiful blue and gold color scheme (our school colors). We then assembled our chassis and our swerve drive modules.

Field & Drivers Updates:
This week, we began drivers practice in the evenings after some issues we ran into with our robots. One of our members proposed a fun basketball-esque competition for determining the human player on our drive team.

Programming Updates:
This week, our programming team set up our second swerve drive and uploaded the code onto it. They also had a writing commands class, finished building a collapsible hub mockup, and ran into some issues with the RoboRIO 2.0. The short-term resolution for the RoboRIO woes is to use the other RoboRIO 1.0 for now. The subteam’s future projects include switching from internal encoders to camcoders for non-manual zeroing and starting simulation for a more accurate shooting trajectory.

Awards and Outreach Updates:
This week, we continued work on our Chairman’s Award submission and the team’s Business Plan. On Sunday, we are planning to get a big chunk of our Chairman’s Award work done by dividing and conquering in something we are calling an award-a-thon (similar to the CAD-a-thon). This Sunday, we are also planning to have a Zoom meeting with Team 6328 so we can double up efforts with our Rookie Kit project.


Adjustable Shooter Prototype

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Credits to @slatier for writing this post!

Hi all, I know it’s been a few weeks, but we are back with another weekly update! So much has happened over the last few weeks so don’t hesitate to reach out with any questions or thoughts. Starting with electronics and circuitry, we now have a robot that turns on and moves! Yesterday, we finished all the circuitry and cable management. Now our programmers can begin to work directly with the new robot hands-on. Regarding the long-awaited shooter, CAD is 99% finished and manufacturing on it will start today. We will post more details and pictures on our shooter this coming weekend. Moving on to the intake. Unfortunately, we haven’t done too much testing on it yet but yesterday, we ran some physical tests. It works mostly as intended while stationary for both rolling and low-bouncing balls. We also established that we need to design and install a polycarbonate plate to make sure the robot goes from the exit of the intake to the entrance of the superstructure properly without getting stuck in between. Luckily, this is something that we fully anticipated and it won’t be too difficult of a problem to fix. Also with the intake, we ran into an issue where the cargo wouldn’t actually go over our chassis because it couldn’t get a grip on the polycarbonate plate between the edge of the robot and the superstructure (plate to protect the circuitry acting as a “floor” for the cargo to run across). To solve this issue, we installed rubber nubs to grip to the cargo and ensure the intake actually intakes it.

7407 Wired Boars comes on The Open Alliance Show to provide an overview of their robot progress including showing off their traversal climber, dual intake and provide a CAD overview.



Hey all! I have been working on updating my CAM–>CAM–> Omio PPT that I initially developed as a part of our CS450 course at Choate. I know a lot of teams have an omio for cutting plates and tubes, and this PPT shows you how to make precise plate and tube parts on the omio with the tube jig from WCP. We have some zeroing scripts written that we included that make zeroing tube x&y and the z-axis for tubes and plate a breeze! Here is a link to the google drive pdf, reach out with any questions you have!


This is excellent. Thank you very much for creating and sharing this!


Dee, can I add this pdf to the 6328 resources page? With full credit to 7407, of course!

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Absolutely! :heart: