Right current value for CD ROM steppers to calibrate with A4988 Pololu

Robotics and electronics discussion Mechanical design and actuators
1

Hi there, before all, Happy xtmas and happy new yeear for everyone!.

I’m newie in this topics and I got a many doubts about CD ROM steppers.I just wanted to build a CNC CD ROM 3 axis and I realized that these motors don’t have any description adn therefore I just can’t to know whos is the factory so that I can calibrate the right current value by means of A4988 Pololu that I got.

Could someome tell me how fix this problem?. Do I assume just one value and make the test-error ?

I`d appreciate very much your help guys!

Thanks a lot!

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Hello.

If you know the original voltage the steppers operated at, you could measure the coil resistance to get an estimate of the current using Ohm’s law (I = V / R). You could measure the resistance of the coils with a multimeter, but you should be careful since low resistance measurements taken this way can be a bit inaccurate.

-Nathan

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Thank you so much Nathanb that’s what I did for OHM law I calculate 5 volts/ 11 ohms (coils) and this result is 0.45 A (450 miliamperes) so I’ve calibrated my Vref A4988 pololu at 0.22 volts.I think it’s gonna be right.I didn’t build it yet.Today evening I 've calibrated my 3 A4988.I’ll se tomorrow if I have some time to get involve a little more.

A big hug to you and have a nice new year buddy!,

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