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Topic: A4988 drives Nema 17 fine but not CD ROM Stepper (Read 114 times) previous topic - next topic

cawoodm

I have 2 Nema 17 stepper motors for the X & Y axis of my CNC build. For the time being I thought I'd employ it as a plotter and use a small CD ROM stepper motor to raise and lower the pen.

I salvaged what I hope is a ubiquitous stepper motor (looks like a PL15S020) and I believe it worked before I disassembled the drive.

I am able to drive my Nema motors with an Arduino Uno and A4988 using the following circuit:


However, when I connect the CD ROM Stepper it just whines and does not turn. I've tried 12v and 5v as the motor power supply. I've also tried swapping the leads around.

What I'm thinking is that maybe the CD ROM stepper just needs a different step pattern. The step pattern for the PL15S020 looks different to what I've seen before.

Little help?


MarkT

All step patterns work with all steppers unless its something exotic like a 5-phase motor.

You need to check the windings are correctly connected, the current is correctly set, and the supply
voltage is high enough for the motor if its a high-impedance one.

So measure the winding resistances with a multimeter - if more than 2 ohms defineitely want 12V rather than
5, and if 30 ohms or more 24V is much more likely to work than 12V.

If the winding current is not know you can estimate it from the winding resistance and size of the motor,
since the motor size determines the winding power (ie the I-squared-R losses).  For instance the bigger
NEMA 17's are usually 4 to 5W.  I = sqrt(P/R)
[ I will NOT respond to personal messages, I WILL delete them, use the forum please ]

Southpark

#2
Aug 13, 2017, 10:43 am Last Edit: Aug 13, 2017, 10:45 am by Southpark
However, when I connect the CD ROM Stepper it just whines and does not turn. I've tried 12v and 5v as the motor power supply. I've also tried swapping the leads around.
So have you got a specifications document for this particular cd rom stepper that clearly shows pin (or cable) information? Such as --- cable XX (or pin XX) corresponds to coil 1A, and cable YY corresponds to coil 1B, etc?

This means...... need to show cd rom stepper pin-outs.

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