Hi @po220, welcome.
Just out of curiosity, what interface do you wish to use for your CNC application, step/direction?
All the demo videos I have are here. I will put your suggestions (slow movements, static load tests, precision tests) in my list of future demos.
This really depends. Of course the stiffness of your mechanical assembly is the most important. Assuming you have a very stiff machine, then there are some other factors:
- Disturbance force: vibration from the cutting
Stiction and other non-linearities.
- Moving mass (larger mass is better, since it makes smaller accelerations for the same forces)
For a very ideal machine, where stiction is low, and under no disturbance, I think something like 1-2 encoder counts is doable. For something like a CNC machine it’s really hard for me to guess about the stiction and disturbance forces. I think someone just needs to measure it on a representative CNC machine, or we perhaps we can find some data from other servo manufacturers.
The short answer is that ODrive is way more efficient, mostly because at zero load it generates zero losses. Skipping a long discussion: you shouldn’t compare torque directly, since these motors can run much faster, so you should gear for that, and then you can use less torque and run more efficient.
For this reason maybe starter motor lead-acid batteries are more suitable. I haven’t actually tried either, but there was some discussion about trying the lead-acid here: Lead Acid battery as charge buffer.