For an offseason CAD exercise, I designed a sheet metal drivebase using Vex’s Drive in a Day Chassis with some slight modifications.
As you can see, I used the WCP SS gearbox with this frame and after some slight modifications I was able to get them to mate at least theoretically. Here is a screencap showing the hole that would need to be made in order for the SS gearbox screws to be able to attach to the frame:
I do have one question for the CD community. Is the two screws bolting the gearbox to the inner rail, plus the fact that the axle would be supported on the other side adequate support say if this was to be used in competition? Any insight provided would be helpful.
Also, per R13, here is where the source files (CAD, BOM, and some pictures) are: https://drive.google.com/folderview?id=0B3OjaSm8md4ES19lTlc3WlhxNms&usp=sharing
Would it be a problem to simply rotate the gearbox a few degrees about the output shaft and avoid the interference entirely?
No, I perhaps should have put up a better screencap. The hole shown in the picture has to be bored on both sides of the large center hole because there are two screws to attach the gearbox.
If you rotated the gearbox, wouldn’t one mounting hole would be slightly above the slot and the other slightly below it?
If you rotate the gearbox 10 degrees around the output shaft, I think you’ll be able to use one (or both?) of the lower mounting bolt and one of the upper ones too.
Even if you rotate it, you would still need to machine it in some way. The native slot only is 2.195 inches from the center of the large hole, while the screw is 2.25 inches away from the center of the output shaft (which sits in the middle of the large hole).
Turning the gearbox would make machining easier, and get rid of the weird hole pattern. Of course, on the other side you would have to machine a hole higher up, but that might clear the other predrilled slots/holes and be more preferable.
Great use of two separately designed COTS items in a single assembly. I would echo what everyone else is saying and make the transmission slightly diagonal. It’s not going to affect performance and will clean up mounting a whole lot more.