I have just sized the DC motors I want to use (corresponding to my robot and its intended applications - my figures include a 50% uncertainty factor to account for friction in reducers and other losses). Now I need to actually choose the exact motors I want to buy from the manufacturer (I am targeting maxon motors as I am not an expert and want no problem). I have a few down to earth questions about linking the mechanical needs to the electrical characteristics:
- Maxon states a "nominal voltage" in the characteristic sheets. Is that the voltage you should apply to the motor? This may be a dumb question but I have followed the full maxon e-learning course and read about other tutorials on the web and I could not find this information anywhere. Can anyone who knows about motors confirm?
- As far as I understand, the nominal torque corresponds to the maximum torque the motor can sustain continuously. So I guess, as a rule of thumb, I should find a motor with a nominal torque = my max torque (after reduction), or around. Right?
- Also I chose a motor reference (310005 found here) which has a stated power of 60W, as the nominal voltage is 12V, I was expecting to have a nominal current of 5A, but it states 4A. Where am I wrong?
- The motor I chose has nominal speed = 7630rpm - nominal torque = 51.6mNm. My needs are max speed = 50.42rpm / max torque = 10620 mNm. This means a reduction factor of 151 for speed and 206 for torque. Should I choose a gear closer to 151 or 206?
- What is the "rated torque" mentioned when choosing a gear? I know my input torque (torque on the motor side) and my output torque (torque on the system side), does that correspond to any of these two?
I have followed some theoretical and practical courses on the web but I find it hard to find answers to my down to earth question...