I would like a high torque motor (37 oz-in @ 5760 rpm) for souping up a Scorbot 3 I bought. I really need it to have an encoder to count the number of revolutions and to allow high start-up torque. So far, I'm having difficulty finding a suitable motor.
The closest I've found are:
- Revolver S Stubby (still not ready for purchase)
- Team Novak Ballistic 25.5T
I've found other RC car motors, but they are usually too big.
Some alternatives I thought about are:
- adding hall sensors to an existing motor - how hard is this?
- rewinding a motor with more turns to increase torque (decrease Kv)
Does anybody know of any motors that fit these requirements or modifications I can make to existing ones?
Update: I had almost given up hope, until someone at Homebrew Robotics suggested using the Maxon motor finder.
If you just type in my given torque and speed, it returns 3 motors, but they're all over powered because the search interprets your specs as a continuous operating point, whereas my robot will only need that much power 20% of the time, and maybe for 1 second max.
If I type in 12V, 5000rpm, and 15 oz-in, then it returns 2 brushless motors, of which, the Motor EC 45 is the best fit, which has this operating curve:
However, I don't want to pay what Maxon is charging, so instead, I've contacted the guy who makes the yet to be released Revolver Stubby and he has kindly offered to build a custom high torque, low RPM motor for me.
Can anyone comment on why high torque, low RPM motors like the one I want seem so rare? Is due to lack of applications (robotics) or is there some intrinsic difficulty in making them?