Motor used?

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Tony Gondola avatar
Does anyone know what stepper motor is used in the EAF? Is it a 28BYj-48 or NEMA 17?
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andrea tasselli avatar
5 wires: unipolar, 4 wires: bi-polar. Nema 17 is a format specification not a stepper specification.
Tony Gondola avatar
andrea tasselli avatar
If it's 42x42 then yes but that still doesn't say what THAT Nema 17 motor specification are like. Although if it fits most likely any NEMA 17 with adequate torque will work.
Tony Gondola avatar
Got it, the NEMA 17 spec. just refers to the bolt spacing in the front plate, the size of the front of the housing, length can be whatever is needed for the motor specifications.
Rainer Ots avatar
Quick Google image serach for "zwo eaf teardown" found several images where the motor is visible.
For example this forum post:
https://forum.astronomie.de/threads/zwo-eaf-klackert-und-rattert.357690/
shows the motor name quite clearly - looks like "35BY48"
Of course it is quite possible that ZWO has used several motors in different incarnations of their EAF product.
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andrea tasselli avatar
Tony Gondola avatar
Ok, so it's mounting class 48, interesting that it's geared down.

Have to say I rather agree with this comment:

"I'm laughing my head off! I buy these motors with a slightly higher gear ratio for around €10 for two. Add the Arduino clone for another €4,
add the 3D-printed housing, and I have the focuser for under €10."
Rainer Ots avatar
There is a whole opensource project doing just that (with ASCOM/INDI drivers, supporting apps, extensive documentation etc.):
https://sourceforge.net/projects/arduinoascomfocuserpro2diy/ 

EDIT: forgot to mention that the popular extremely cheap Gemini focuser is just a ripoff of that project.
Tony Gondola avatar
Thanks, that will be a great resource. I'm not looking to make focuser but I am interested in making other devices that I can control via ASCOM.
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