educa wrote:Thats an easy one - 4 wire and 8 wire doesn't matter
I do not agree entirely. 8 wire does have the advantage of series or parallel connecting. For low speed, low current you can connect them in series.
When you want high speed you have to reduce the selfinduction. By connecting the wires in parallel the selfinduction is a fourth of that when in series.
You need twice the current however. Can your supply deliver this current? The voltage should be as high as possible (if you use 80V drivers, look for a supply of approx 70V for instance)
Ofcourse holdingtorque is important but more than that, you should look after the inertia and the torque-curve (torque/StepsPerSecond RPM)
For a laser you want to reach high speeds in almost zero seconds.. That also has to do with the weight you have to move.. A bigger motor also weights more.
There is quite a lot to think about when you want to get the maximum out of it..
Nowadays drivers do upto 200 microsteps, giving you 40000steps/rev for a 200steps/rev motor.. You probably need only 4000, why should you have to use 400step/rev?
Kees