Swerve drive forks

[Jonathanshani]

Hi everyone!
Since the major explosion of swerve I have been thinking about how my team could manufacture a module with our current set of machines (a manual mill, manual lathe and CNC router).
As a fun challenge, while fully knowing that if we do try to design our own module we will probably take a different route, I decided to try to come up with a way to manufacture the wheel forks using an aluminum plate on our router without adding a second process (drilling holes on another face with the manual mill or something like that) I do have some ideas but I’m sure that others tried to do the same thing in the past so I’m here for some inspiration!

If anyone has something to share I would LOVE to see it!

[Schmools]

There are lots of way to insert a nut sideways into a fork to attach it. I do this kinda thing a lot with some printed parts and inserts (the printed parts don’t need to be load bearing - they just act to allign the nut): https://gitlab.cba.mit.edu/jakeread/rctgantries/-/raw/master/beams/images/acrylicbeam.jpg

[AriMB]

We made our swerve this year in-house with those exact machines, and it’s worked with minimal problems this season. You can find the model here. I’m sure the students would be more than happy to answer any questions and explain how all the parts are manufactured.

[Skyehawk]

2767’s 2017 module is a good example of just using aluminum C channel for the fork, with a few carefully placed holes on the mill.

[Jonathanshani]

Would you mind sharing how did you drill the top holes? I assume it was on the mill but was there anything you did to help with the accuracy? Were there some you had to throw away because of machining mistakes on the mill?

[AriMB]

We designed our modules with two bearings in the main pulley body and the small bevel gear cantilevered so we wouldn’t have to mill a pocket for the vertical bearing in the side of the fork plate. We’ve seen a bit of wear in the bevel gears over the course of an off-season of testing and a season of competition, but nothing worrying.

[Jonathanshani]

I was reffering to the 2 threads that conncet the forks to the rotation pulley. The double bearing is something I noticed and I think it’s a great way of simplifying the design.

[AriMB]

I’m pretty sure we did those on the manual mill. With a DRO we can get bolt holes plenty accurate on there, though it would be possible without the DRO with some care.

[Bruce_Newendorp]

This design is manufactured with a CNC router and lathe to cut the dead axle to length. The two vertical holes in each fork are match drilled when the forks are inserted into the inner round base. CAD located within the 2021 robot model here: http://525swartdogs.org/robot-code/

[Jonathanshani]

This looks really interesting! I’ll take a look when I get home. Thanks for sharing!