The Need For Speed!

My team had a practice tonight and decided they wanted to try making their robot move around the field faster. Currently they have 393 torque motors directly driving the four wheels (two standard 4" wheels in front and two omni wheels in back). Trying to do any gearing would require a massive redesign, so I was wondering if they would have be able to just switch the internal motor gearing to high speed? I am concerned about running into PTC trouble, so just curious if anyone else is running four direct drive high speed 393’s on 4" wheels on about a 20 pound bot?

I’m not sure how much our current robot weighs, but we used speed motors on 4" wheels last year, for Skyrise, and we never had stalling problems, and it really was not the lightest design. I would say, based just on my recollection of lugging the thing around everywhere, that it was more than 20 pounds. You should be fine. You can just get 4 more motors with speed gearing and change them out for your torque ones. That way, you can easily replace the 4 motors if your drive does end up stalling. Also, you might look for places you can reduce weight. For example, if you have a large bendy plate somewhere, and you’re not using polycarbonate (or another allowed plastic), you can replace it with plastic to cut down on weight.

You will be fine with that gearing.