1. ## Bad stepper motor ??? How do I determine?

I'm running a small carving machine(home built) using a 3 axis controller from http://www.stepper3.com/31.htm. Up until today the unit seemed to be operating just fine. With some loss in stepps. My motors are 6v/1.2amp unipolar types. I'm using a standard 12v supply with 1 ohm resistors on the power legs. I was just informed that the correct resistor to use should be a 3 ohm for this setup???

(12v psu)-(6vdc motor)
------------------------------ = 3 ohm resistor,
2 amp current

What I found after playing around a little today was, one of the motors had basically no toque.

Could I have burnt this motor? How much current would be to much?
Neil

2. Where does the resistance of the windings enter into your calculation. I'm a noob at this stuff, but is it correct that that the resistance of your windings would be 5 ohms? That would make a total of 8 ohms, then, which would allow only 1.5 amps to flow.

(Shrug)

Maybe Balsaman could answer this, he's a real smartie at this stuff, amongst others (no offense meant to others )

3. Here is the steppercalc screen shot: It indicates you need 4.25 ohm resistors. 4 would probably be fine (1.23 amps at the motor). Your 1 amp resistors make the motors draw 1.85 amps each. That is plenty high. Were they getting very hot?

Eric

4. If you were using one resistor per motor it should be 2 ohms.

Eric

5. ## Hi...

Great avatar you have there Thuffner3,

I don't know if you are familiar with that character, but earlyer this year that albino Gorilla passed away in Barcelona, after illness.

Nah...You probably heard that allready somewhere else.

I thought you might wanna know if you were unaware of this.

Good luck with your project, yes i noticed that too

Ed'.

6. ## Re: Hi...

Originally posted by Mr.Ed
Great avatar you have there Thuffner3,

I don't know if you are familiar with that character, but earlyer this year that albino Gorilla passed away in Barcelona, after illness.

Nah...You probably heard that allready somewhere else.

I thought you might wanna know if you were unaware of this.

Good luck with your project, yes i noticed that too

Ed'.
Thank you Mr.Ed, I didn't know this.

7. ## Burnt motor

Could I have burnt this motor, or is the over current cause the loss of torque? When the motor is stationary I can with very little effort, rotate it.

8. could be cooked...did you try it on another axis?

Eric