Please feel free to ask any questions about the team, strategy, or robot and its code. Note that we do not publish our CAD, but I’ll be happy to provide screenshots and explanations of subsystems people find most interesting.
Some other recent posts I’ve made on this robot or topics about our team in the past year:
@Torrance
Thanks for sharing this!
A great pleasure to learn from you guys
A few questions if I may ask:
Could you please share the spec/name/ link of the Teflon Tape that you used for covering up the polycarbonate plates? We’ve been looking for one and hasn’t found anything satisfied.
Could you please share more about your prototyping process through the season? How you select the best systems from the ones you check? In what time a prototype goes from rough build to something more planed(wood laser cut) and how it develops to your robot model in the end
Just throwing this out here now that the tech binder is finally released - our old amp mech could do trick shots! We ended up removing cat tongue tape from the bottom roller to trap better, but this sadly got rid of the backward scoring capability () so we never got to run this at competition.
We actually sanded the polycarbonate plate. We just used an orbital sander, seemed to work well for these notes. We also used teflon from mcmaster for other polycarbonate parts. We used the ultra low friction but its expensive, there are cheaper tapes we used for prototypes. McMaster-Carr
The backside of the shooter was mainly made from 2 things: on the outside (away from the note path) was a nylon 3D printed ramp made on an HP Multi Jet Fusion printer at one of our sponsors (J&J Medtech), and the inside was a 1/32" bent aluminum plate, both covered in teflon tape for better note travel. The aluminum was stationary while the 3D-printed ramp moved with the hood, providing support for the aluminum even when it was angled near horizontal.
Every once in a while the poofs do something that makes your realize they are in fact human, like committing build artifacts like .jar and .class files to github
The tech binder references that the energy chain you used for the turret (the “BIGUS”) is 3d printed and a custom size for this specific application; Could you provide some detail on how you drew the energy chain, and what method was used to print it (desktop printer, markforged, HP multijet etc)?
For designing the energy chain, was it as “simple” as downloading a vendor’s CAD model of an exisiting chain, and adjusting for the overall dimensions needed to house the shooter subsystems wiring? Or was the design process more involved than that?
Regarding your first question, I assume you are asking about planning out the layout of the chain. We started off by “prototyping” the energy chain layout on a table with constraints marked out like bellypan dimensions, position of electronics, and space/length needed to wrap around the turret +/- 360. From this we determined how many links we needed, the position of the tensioner, etc. that we then ported over to CAD.
The actual links were designed pretty much as you guessed, just by porting over a model from an existing chain (W̶C̶P̶ i̶i̶r̶c̶?̶ sourced from Igus) and adjusting dimensions and strengthening the tabs for our purposes. The links were then each printed separately on the HP MultiJet and assembled.
When we borrow JnJ’s MJF, we get a batch so we are incentivized to use as much of the print volume as possible. The volume was enough for both robots and spares. It took about 1 day complete.
Edit: just to explain roughly how an mjf work, it builds up powder layer by layer, so print time is how much of the volume is filled. Seems like based on the size of our parts, it was best to run using the full volume (completely filled with powder). The print time efficiency goes up as your increase the number of parts. Its very cool technology. We were very fortunate to use it a few time this season.