pic: GBX-150, CIM-mounted swerve

[asid61]

Originally Posted by Ari423

I always love seeing your designs.; they are the reason I taught myself CAD so Icoukd aspire to make stuff like you do. A sub 5lb swerve module is an amazing accomplishment! I have a few questions:

1. How is the small bevel cluster shaft being held in (on the top and bottom)? I see there's something under the small bevel gear but I don't see what it is.

2. Unless it's an interference fit, I could imagine a scenario where the robot rides up on a field obstacle or another robot and the gear gets pulled off the large bearing. In your first version of 150 you have screw holding the gear and bearing together. Did you remove them for weight savings or was there another reason?

3. Is there an encoder on the CIM that I can't see? I though that was usually a requirement for swerve.

1. There is a 5mm bearing in the fork, and a 9mm bearing up on top. Gratuitous use of fillets in the corners might save it from shearing, along with the use of a steel shaft and lower loads. That being said if I did it again I would switch to 3/8" wide forks and use a 6mm or 7mm bearing.

2. I sort of see what you're getting at, but short of 2016 obstacles I can't think of another field or situation that would cause that much odd loading. Cyclic loading of some kind might work it loose, but probably not in a single match or even several matches. The amount of force required to dislodge a press fit or loctite in one go is way more that you'd expect.

3. There is not an encoder; I couldn't find space. I know teams have done swerve without encoders on the drive motors before, but I don't particularly like it.
I removed the screws due to an interference with the versaplanetary and the screw heads. looking back on it, I think I could have at least put some set screws on the gear to hold the bearing in place.