Team 4096 Ctrl-Z, working in Creo 3.0, decided to design and build a grasshopper drive over the offseason to be ready for a good drivetrain in build season. The goal this time was to minimize costs by using only flat machined parts, no bends on the entire drivetrain. In addition this allows us to hand-make some of the parts or laser-cut them out of wood for prototyping before we get them machined.
The frame is connected by bars of 1010 profile 80/20 and the wheels driven by belts powered from a VexPro 3-CIM ball shifter with 2 CIMs installed. Using Vex omnis on the outside on a driven shaft belted to the gearbox, the omni is belted to the tank. The tank is mounted on a lever module which is controlled by a central Bimba Square-I piston. The lever module is mounted onto a piece of tube stock which is on a shoulder bolt. For the H-drive, we have a VersaPlanetary 16:1 gearbox with a CIM, an omni wheel directly on the shaft. That gearbox is mounted to two bars of 80/20. This configuration allows us to switch an H-drive and a tank drive with ease. Should our air run out, the robot can revert to one of the drive systems for the rest of our match.
We ran into a couple of issues while designing this, such as mounting the gearboxes and making sure that our lever points are sturdy. Since we're sure we missed something, we would love your suggestions on everything related to design and rendering. If you have Creo 3.0 and would like to check out our files, go here:
https://goo.gl/2LNJ9O. Download the entire folder, then the complete drivetrain assembly is called assembly_drivetrain.asm.
Thanks!