Need Help!- Replacing a Stepper Motor

[AndrewEvans]

Okay, So the bearing inside the Stepper I have is shot, I cant find the bearing so I have to replace the Motor itself, the company that sells the cnc kit I have says it's 250$ to replace the motor, this after I find the same (almost) motor for 70$ online.

My question is/are "are these differences enough to warrant biting the extra 180$?


Original - > replacement
269 oz-in - > 269 oz-in
2.1A/P - > 2.0 A/P
1.7 Ohm/P - > 2.0 Ohm/P
8.0 mH/P - > 6.8 mH/P


Additionally it seems that the original motor is a 2 phase 4 wire, and the option is 2 phase 8 wire, will that play havoc with my driver?

*begs for help*

[doorknob]

You should be able to replace a 4-wire stepper motor (with bipolar connection) with an 8-wire stepper motor.

There are a lot of web pages that discuss connection options (you would need to decide between bipolar serial and bipolar parallel hookup).

Here are a couple of pages with such discussions - there may be other, better ones out there:

Stepper Motor wiring

Slowing 69.16.243.61&c=1&t=40582.7056840278

[AndrewEvans]

Well, I guess that solves one question (wiring-wise)

but all the rest of the numbers shouldnt matter then?

i.e. "close enough is close enough" as far as inductance etc?

[doorknob]

I am not an expert in this, however if it were my project, I would go ahead and make the substitution.

[AndrewEvans]

well thats kinda what I thought too *crosses fingers that the substitution works just fine because I've got a few plates that need delivered end of next week and my plasma table is the only thing that will be able to cut them out

[AndrewEvans]

not a problem at all, their old motor still running the y axis, my new slightly different motor running the x axis, circles come out circular, squares come out squares, the wiring swap was a piece of cake, even got the poles right the first guess.

I guess the only word of advice I would have to anyone replacing a motor for a small table is the following, dont pay 4 times more than you need to when doing it and just check out the steps, frame size and torque you need, get the frame and steps the same and the torque relatively close and you'll be fine

*OPINION SUBJECT TO CHANGE

[doorknob]

Glad to hear it worked OK...