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.