pic: FRC3928 2013 Butterfly Module
 

Re: pic: FRC3928 2013 Butterfly Module
 

what kind of hub did you use for the traction wheel?

Re: pic: FRC3928 2013 Butterfly Module
 

Since your cylinder mount doesn't pivot, could you go into some detail about how you attach the cylinder to the module?

Re: pic: FRC3928 2013 Butterfly Module
 

It just pushes on a standoff. There is some sideways sliding contact but it's a non-issue.

Re: pic: FRC3928 2013 Butterfly Module
 

If you're having trouble visualizing, you can check out this video of 3847's modules from 2014:

https://www.youtube.com/watch?v=GF_CP-9eMDY

Re: pic: FRC3928 2013 Butterfly Module
 

Ah, that does seem like the simplest solution. Thanks!

Re: pic: FRC3928 2013 Butterfly Module
 

In this instance the traction wheel was made from a solid piece of 2.5" diameter Delrin, the Pulley was milled into the side, and two 3/8" bearings were pressed into it.
Had access to a CNC mill, decided to minimize the part count and not require ordering a pulley.

-Aren

Re: pic: FRC3928 2013 Butterfly Module
 

And now I know where Adam got his 2013 offseason drivetrain design.

Re: pic: FRC3928 2013 Butterfly Module
 

What would someone look for if they were trying to find an extrusion like you guys used for the main structure of these rails? As well, how are you planning to connect the frame up once both side rails are completed? The pattern of those holes looks like it would be great for designing attachment points.

Re: pic: FRC3928 2013 Butterfly Module
 

As this was our 2013 robot, you can see how the frame was designed to be assembled here.

Re: pic: FRC3928 2013 Butterfly Module
 

Also for reference this is 3"x3" x .125" wall Aluminum tubing, nothing special.
Online metals has it but a local supplier will give a better price.

-Aren