Looking for specific motor

hello can anyone help me identify the specific motor that are used in the “version 2” video of the plotter found on their home page?


That is @madcowswe 's build. Is there a reason you’re looking for that motor specifically?

That motor happens to be the Hobbyking Donkey ST4010. I’m not so sure I would recommend it, but it was cheap xP.

i’m experimenting with electric valves on a small engine and that motor looked like it was small and fast enough for some preliminary testing.
something cheap that i can use to develop some measurement protocols and quantify various output parameters of my electronic designs before i go shelling out for a more robust and powerful solution.

Ok thanx but i’m missing something. that motor is a BLDC. i was assuming that the motor in your plotter machine is a servo. What’s the control mechanism there?

ODrive! That’s what ODrive does - it takes boring BLDCs, and turns them into servos with the help of a feedback encoder.

Take a look at Oskar’s blurb on this page: https://odriverobotics.com/

And the documentation is available here:

Motor guide here:

WOW that’s really something. So maybe i could use a BLDC to drive an engine valve. i’ll have to figure this out and calculate force and wattage n stuff. it’s good to know that this alternative exists, although at $120 for the board it looks like i would probably have to make my own.
does it really have resolution like a stepper?

It depends on what encoder you use. A “standard” stepper motor is 200 steps per revolution and has 16x microstepping, giving 3200 counts per revolution. The inexpensive CUI AMT-103 encoders that are sold on the ODrive store are 8192 counts per revolution. You can also get higher count encoders - industrial robotics use resolvers and other methods to give them multi-million counts per revolution. Plus if you over-torque it, it doesn’t “miss” steps.

well that’s about 20x more res than i need so it’ll certainly work. i gotta look into this to see how feasible it is to DIY with the github docs.