So my team has secured a couple of sponsors for Swerve, to the point where we are actually getting full CTRE Swerve covered which includes 10 Krakens (8 + 2 extra), 5 Cancoders( 4 + 1 extra), and 1 Pidgeon 2.0.
So basically my question is what did your team encounter while developing Swerve that y’all didn’t expect to need? (extra wires, wire sleeves, power wires {specifically where do we buy those from}, also anything else from CTRE like canivores or anything like that)
Also, how stupid would it be to just mount Swerve to like a piece of plywood and then put all the electrical components in the middle?
I’ll respond to this part since i think other folks will give better responses to your first points.
Make 4 2x1 frame rail bars, mount your swerve to it, mount a wood board to the bottom of those rails and you’ll have a functioning chassis bot. We keep a bot just like that for testing various mechanisms, haven’t had any issues with it
I’d say that we needed the ring terminals (if you aren’t using the power poles) and the torque wrenches for the power/can. Next, this will be unexpected but it’ll make sense. We needed a 3d printer. From swerve guards to camera mounts. There are so many uses for one when it comes to swerve.
Oh I see, I didn’t know this was a thing, just to make sure the Krakens come with the cables that go into those connectors? and as well as the screws that are being torqued?
Yes it comes with the connectors, wires, and screws. However, the wires are a little short. You can use 12 or 10 gauge wire (10 gauge is recommended). So if you plan on making the wires longer.
Ring terminals like these for power and CAN (10 gauge and 22 gauge are needed)
im afraid im still confused on the overall wiring of the motor, so allow me to try and re-confirm, you place the ring terminals over where you want to put the screws and then you torque those screws down, then you connect those wires to the ring terminals and connect those to your power hub. What about for can wires? is it the same thing but you just connect it into the rio? Do the different colors of the can wires go into the H and L ports on the motor? I’m looking at the docs but they do a poor job explaining.
You only need ring terminals on one end of the wire. These ring terminals will then be screwed into the back of the krakens (with the screws pictured earlier). The power and CAN ring terminals need slightly different torques (how tight the screw is) to secure them to the kraken. The other end of the power wires will run to the PDH (rev’s power board) and plug directly into the PDH with no connector. As for CAN that’s a little bit more complicated because with a full kraken swerve I recommend (it’s not 100% needed) a CANivore and Pigeon. Yellow CAN wire is the H on the kraken and the green is the L. The layout out of CAN is a bit more complicated than I can easily explain.
There is also a second option to connect krakens and it’s the power pole adapter board.
This probably isn’t true for your rookie year… but hold onto those sponsors because you’re likely going to want another chassis or two as your team expands.
Also- really really good wiring. If you need some guidance feel free to reach out to 2491 or me directly.
More time in code and driving than you expect. There will be significant issues, and you’re going to want to figure out autos before the season starts. Be ready to be running paths with a physical chassis week 1 as best you can.
A back up swerve module, and know how to swap the entire thing out in minutes. Often, if anything goes wrong with something electrical on a single module, it’s best to replace the entire thing at a competition.
Spare tread. You’re going to want to replace it 1-2 times per competition.
that wouldn’t be stupid at all! our first swerve bases were squares of 8020 with plywood.
one thing you will definitely need, though, is BUMPERS. kraken swerve with no robot on top goes FAAAAAAAAAST. you will hit things, you will hit students. BUMPERS. BUMPERS. BUMPERS.
The CANivore allows you to add another CAN bus to the robot that has higher speeds. CAN utilization can get pretty high when you start adding that many CAN devices. The CANivore has CAN FD which has a higher bandwidth. Only certain CTRE devices are supported though. The layout of CAN often referred to as topology (so you can research it later). I believe CTRE only recommends daisy chaining for the layout. More info can be found here.
Having a spare set of wheels with bevel gears on them makes tread replacement much faster as you can just swap the whole wheel and the robot is ready again and then changing the tread on the new spare wheels becomes a parallel side task to running the robot.
You should keep a spare piece of straight stock that you can use to zero the wheels with. We keep GDB (gosh darn beam) which is a 30in 2×1 in our cart in case we ever need to rezero a module.
While our team used the Rev MaxSwerve with Neos, in general its a good to have spares of wheels/tread, calibration jigs (Rev supplied one for each module), encoders and any pinions. We kept a fully built spare module at all times to allow us to swap in a hurry if something broke beyond usual maintenance. In those cases the time to diagnose and fix the problem between matches is too short so it’s faster to do a full replacement and diagnose/repair it and someone can stay behind and work on it while the bot is back in action.
I’m sure the specific part list varies, but the pinions/gears can/will wear out over time and that’s not as easy to borrow from another team as an encoder or motor controller is. Especially if you have a specific speed set of gears for your other 3 functional modules.
Also although others answered this already
We did basically this and used lumber to act as our extrusion for the perimeter. The base was white expanded PVC which we use for prototyping. It’s easy to cut on a Xcarve/CNC router or by hand and available locally.
Not stupid at all, and it got us up and running quickly.
