[macdowswe]

Yeah they are open. I was thinking of making a shroud that houses a motor/encoder assembly, and that has an air inlet with an intake filter, and a fan for forced air cooling. This can probably increase the performance at low speeds fairly significantly since the motors own air cooling doesn't work unless they are spinning at high speed.

So about the cooling and thermal management of the motor, the above is the plan. Actually, just to enumerate some of the possible ways to prevent overheating:

1. Use reduction gearing to reduce torque required from motor
2. Oversize the motor
3. Use forced air cooling
4. Active thermal management/control, with motor temperature feedback (using a thermistor or similar)
5. Most importantly: lots of testing.

I think in the end there is a large range of motor sizes available, and the power to cost ratio of these motors is really good. So getting the right motor shouldn't be a big problem. After I get back to a proper workstation after the holidays, I will make a spreadsheet to help people pick motors for their application, and include some motors I recommend (and of course have it so people can add their own motors).