Hi, I'm an arduino beginner and I'm building a telescope mount with 2 axes driven by two NEMA 17 stepper motors with a max. power of 2 Amps each. I connected them with a CNC Shield and I am using the A4988 Drivers. - As a power supply I use the battery packs of my drilling machine, because I want to be mobile with my telescope. It has 18 Volt and 4Ah. I adjusted the Vref to 1.2Volts (formula is: Imax * 8 * 0.1 = 2 * 8 * 0.1 = 1.6V as optimum - 1.2V was the max. Vref of the drivers).
After my first trys the steppers made weird fwd+bwd moves and at the end I burned my drivers.
I re-ordered a CNC-Shield, now with DRV8825 Drivers.
I need some help from experienced developers, if my setup is ok, and what I have done wrong.
You need to know how much current those drivers handle. I've used A4988, with heatsinks and fan cooling to operate them at some 1.5 Amps I think it was.
You do not have to set Vref (coil current limit) at max. Set it high enough that the the motors perform adequately without missing steps.
Stepper basics:
Blockquote
The DRV8825 drivers are good for 1.5A with no heat sink and 2.2A with heatsinks and active (fan) cooling. What are the specs of your steppers? Please post a data sheet for the motor.
Thank you so much for your replies. This helps a lot.
One question is still open for me, where I can't find any information about:
Does my power supply (The battery of my drilling machine) fit to my setup?
It has 18Volts and 4Ah.
I'm using 2 Nema 17 with this specification 17HE19-2004S.