The larger the gauge the more likely it is to melt . . . that is what they do.
. But we had the atwoods and the drills geared up together on a single shaft using the gear boxes that First had provided us with. I believe the ratio was some where around 3:1 or 7:2, don't quote me on that because it seems like a long time ago since we were working on the gear ratios. But whatever it is it works fine because the two motors aren't grinding themselves out at all, and also there is no problem when we run the robot up on blocks it runs just fine, leading me to believe that the motors would have to be geared properly. We were using green brexoflex treads, so if anyone else was using those tell me if you had any problems with them, because it is my belief that those things were sticking to well and the atwoods and the drills were pulling so much power!