Here at Wave Robotics we’ve spent the last several months working on designing and refining a differential swerve drive.
2826 Differential Swerve (Onshape)
Before I type about the module, I’d like to give a massive credit to team 4909, Bionics. Their module forms the basis for almost all of the work we did. Thanks 4909!
Our priorities when designing were
- To make the module as easy as possible to replace in the event of a failure
- To reduce part count as much as possible while maintaining the ability to manufacture as much as possible in house.
- To make service and assembly as simple as possible
Here it is! The module mounts to the inside of a 90 degree joint between two surfaces (2x1 tubes in our case). Those fancy plates with the logos are the hardpoints (and yes it is sad that the logos will eventually be covered. They’re still cool though, and that’s what matters). To unmount it, simply unplug and pull out the bottom of the robot. Have a spare fully assembled to push right in where the broken one came out and you can repair a broken robot in a couple of minutes!
It has a lot of interesting stuff happening in it, from using wingnuts with 3d printed parts for some tool-less nuts to a bit 1.5" hole right through the center of the wheel. It relies heavily on 3d printed parts, most coming off of our desktop Markforged printers. At about 7.5 lbs it is reasonably competitive for a differential swerve module. We try not to think about the ~$550 cost per module. Considering that, our future is probably filled with triangular robots.
Good luck this season everybody! I can’t wait to see what we all build!