What happens if you change the dimensions of a stepper motor?

Hey everyone,

I've been looking around for smaller stepper motors for my project. Reprap uses predominantly nema 17's, but i've found that you can have nema 08's! The problem with this is that they produce minuscule amounts of torque and would be useless. Would it be possible to increase the length of the motor? What sort of effect would this have?

Thanks
- Jaysen

... yes, longer motors can produce higher torques - it's the 'volume' of the magnetic field and geometry of poles and gaps what's defining the resulting forces.

For a special application I had to use a 'long' NEMA-14 motor with the same torque as a standard NEMA-17 for the limited sizes ...

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Does that mean you could have a 20cm long nema 8

I just saw a trinity labs NEMA 11 with a long motor stack. Hard to know if it is a double stack or what?

I used some NEMA 8 motors, but to create the torques required amperage levels that smoked the motor.
I think it borked at 1.5amps.

Trinity also identifies the need for active motor cooling in their product description.
These small motors get very hot.

I have a NEMA 14 with 5:1 that weighs .5lb or 225 grams, which is ironically less than the NEMA 11.
Kysan part number is 1040125 and they cost $35 each.

Is this the trinity labs one?

[trinitylabs.com]

It says triple stack..


Shame they get so hot!

reading is fundamental. I should try it.

Haha it's fine, we all slip up sometimes

You may want to drop the stepper requirement.

Geared servo might work out better for your application.

Long thin motors have less rotational inertia compared to short fat ones with the same rotor mass.

Edited 1 time(s). Last edit at 05/06/2013 02:38PM by nophead.

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[www.hydraraptor.blogspot.com]

So, how do you like that Nema14 motor with the 5:1 gearbox? Where did you get it for $35?

davew_tx Wrote:
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> I have a NEMA 14 with 5:1 that weighs .5lb or 225
> grams, which is ironically less than the NEMA 11.
> Kysan part number is 1040125 and they cost $35
> each.

Yes, but according to the data sheet, your NEMA 14 geared stepper has less than 1/3 the torque at the output as the triple-stack NEMA 11 geared stepper. 4.5 kg*cm vs 16 kg*cm.

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