Hi!
I'm going to build a stepper motor controlled time lapse for my camera using an arduino.
I need a stepper motor that can handle a heavy camera (1 - 1.5 kg) on a camera slider.
I bought a cheap stepper motor with a driver board on ebay (28BYJ-48) but this stepper is really slow and weak.
I was looking at the NEMA17 stepper motor, that runs at 12v. can I still use my stepper motor driver (ULN2003A), or do I have to replace it with a driver that can handle more current? This motor has only four wires (no ground wire), instead of five, like the one I have. How do I wire the motor?
can I still use my stepper motor driver (ULN2003A)
No.
because
This motor has only four wires
The 2003A only pulls down, you need a H-bridge to drive it.
but this stepper is really slow and weak.
It could be the driver or the supply that is weak. What current rating does the motor have?
see:-
http://www.thebox.myzen.co.uk/Workshop/Motors_3.html
and
http://www.thebox.myzen.co.uk/Workshop/Motors_4.html
Generally, steppers are driven at much higher voltages than 12 volts. I have just been through this and it takes a bit of research.
I have an 18.5 volt laptop power supply which seems to do a fair job driving a NEMA 17 but I have not finalised my configuration and my push the voltage higher yet. It could also be that your controller does not deliver enough current.
High voltage is only needed for high speed with bipolar chopper drivers, but it doesnt hurt. Something like an A4988 driver would be fine for most NEMA17's. Unipolar
4 wire motors are bipolar drive (and need dual H-bridge as a minimum requirement). 8, 5 and 6-wire can be driven unipolar.