Nema 17 Servo Motors

I have been designing a large format 3d printer driven with torqspline lead screws powered by servo motors. Before I found out about Odrive, I had been using this project with good results. I feel like the Odrive is a more streamlined solution, and would offer much better performance/functionality for only a little more money.

I’ve been planning on using 42BLF02 brushless motors for my project, because they seem to have good characteristics for this kind of project, and are cheap. I also can get them customized even on relatively small batches for things such as dual shafts and rear encoder mounting holes for no extra charge. They are rated for 4000 RPM and 0.38 Nm at 24v. Before I looked into the Odrive, these seemed like a no brainier, because the peak current is only 10.2A, letting me use cheap brushless drivers (maximum of 20A). With the Odrive allowing much higher peak current, is there any reason to consider using RC hobby motors? The motor drive chart for the odrive provides a lot of good details, but it’s hard to compare those values to the specs I have for these motors for things like acceleration. Maybe someone has more experience than me on this topic.

Here are the specs for this motor type:

Ignore the price, they are not really that expensive.

Hi @Klosking, welcome to the ODrive community!

The motor type that you mention seems very good for replacing steppers in existing designs, due to the Nema 17 form factor. If you could get the factory to fit a decent (600PPR or so) encoder on the back rather than the hall effect sensors, it should be a very attractive solutions for things that don’t need the kilowatts of the outrunner motors, indeed like 3D printers.

I would suggest you have a look at the ODrive motor guide. I apologise that this document is not very easy to find, it should be once I finish building the ODrive website.
I would suggest to make a copy of the document, and add a row for your motor, and hence compare. You can bypass columns like “kv [rpm/v]”, and just enter the torque/speed directly.


Where do you source these motors from? I’m interested in buying a few myself and could use a recommendation for a decent supplier.

You can get a small quantities from

I am in contact with another Chinese supplier that will provide similar speced motors for less than half this price, but I need to order 100 at a time. If you want to wait a month or two for me to make my big order I can reserve a few for you for much cheaper than anaheim.

Too funny, that’s the exact supplier I ended up finding as well. I bought two of the BLY171D-24V-4000 motors for prototyping.

I would also be interested in the Chinese supplier, as if this goes anywhere eventually I’d be looking at annual quantities of over 1,000 motors.

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