Hi everyone!
This probably takes the crown for the latest CAD release this season but, alas, better late than never. I hope that teams find this interesting and at least somewhat helpful. If you have any questions feel free to ask here!
As a side note, our code is and has always been open source. Check it out here if you’re interested: GitHub - HighlanderRobotics/Crescendo.
Our 2024 Robot, Banshee, was 8033’s fifth robot and only our third that competed officially. Above all, It was by far the most robust robot 8033 has built, and it’s architecture was more carefully planned than on our previous robots, due to a new workflow. Banshee had a great season, including a finalist finish at SFR, our first appearance on a first alliance at OCR, and a finalist captain appearance in the Milstein division at champs.
Check out the CAD here: Onshape
Technical Highlights
Shooter
Banshee’s shooter uses two independently controlled sets of Stealth wheels to create spin. While similar to many other designs, it does stand out in having a Maxspline cross shaft that takes virtually all of the torsional load and allows the shooter to be driven with a chain from just one side, without twisting or flexing during operation. In fact, this Maxspline functions both as the pivot point, on top of a .75 diameter extrusion with needle bearings, but also as a roller for the notes - a deadaxle roller rides on top of it through the use of a large thin section bearing from TTB.
Elevator / Amp mechanism (+ trap arms)
Banshee’s elevator was designed around simplicity. It’s cascade rigged with UHW cord and tensioned with WCP ratchet plates, which were super sweet to work with. It’s driven by two Krakens on Maxplanetary gearboxes with chains and the TTB chain combs. There’s also a servo actuated latch for our climb.
The Amp mechanism uses several sets of rollers to deposit the ring into the amp and also hold it laterally. In our original geometry it could score in the trap using the arms but in reality this was not reliable (hindsights 2020). It did however contain the hooks used for our backup climb and worked great for that purpose.
Drivetrain / Intake
Our drivetrain used Mk4i modules with Kraken X60s and worked great for us. While we started with L3.5, we ended up going down to L2.5 which allowed us to push through defense more effectively with our TPU wheels. If anyone is interested in those the CAD is here: Onshape. I can share print settings if people are interested.
Our UTB intake was also similar to many teams using 2 sets of deadaxle rollers with the frontmost one wrapped in silicone. The centering worked great using two sets of powered 4 inch compliant wheels. One thing you’ll notice throughout the CAD is the use of pulleys with oversized flanges. I definitely recommend these - especially on longer belt runs like the one on the centering wheel assembly. If anyone wants the CAD it is available on Configurables - FRCDesign.org.
Conclusion
While Banshee was a great robot, it both gained and suffered from its emphasis on robustness - which led to weight. Banshee weighed 124lbs at worlds - something that we hope we won’t repeat in the future. Like anything, it’s a fine balance. Additionally, like many teams, bumpers were a pain point for us this year…
If people are interested, I might make a post about our bumper design for next year, which I’m considering to be “battle proof”.
Anyway, hope to see ya’ll in 2025!