pic: WCD Butterfly Module

Modular butterfly module for a WCD. Can bolt onto many WCD chassis with only a modification to the axles.

That’s a really cool design. What is the weight of the chasses? Also when you have the high friction wheels down are the Omni wheels touching the ground?

I don’t have weight numbers at this point. The chassis itself is one we developed last summer and used this past season. So the only added weight would be the modules themselves.

In this configuration the omni wheels are allowed to ride along on the ground. Adding a spring to pull them up, if this was undesirable, would be a very easy addition.

Since they’re geared 1:1 I doubt it’d matter too much if they rode on the ground. They’d have next to no normal force anyway.

Very cool design. The use of the front rail as a brace for the piston is a bold idea.
I noticed that the drive chain will have to run from the center gearbox all the way to the corner so that it isn’t on the pivoting sprocket (with a changing C-C distance). But if it does that, then the chain goes through the pivoting sprocket. You might want to make the pivot point the sprocket that’s closer to the chassis to avoid this issue.

Agreed, which is why the option was not added currently. My only worry is carrying the robot, they might have a tendency to want to swing down. The pneumatic tubing might keep this from happening though.

This is actually a chain in tube chassis, the chain run is identical to our chassis without the modules on it.

I really like this approach on how to make a WCD Butterfly drive!