You should look at the motor rated currents, but as a rule of thumb, I say that Nema 17 Steppers up to 48mm long are OK, as long as you are not putting way too much load on them. They can work up to a point, then you will need external drivers. These are Trinamic stepper drivers rated up to 1.2 amps (RMS value, which is different than the peak which is how most motors are rated). I will be able to add some pics of that then. I don’t have pics of the old controller attached here sorry as I am currently home and machine is at work. I really want it running as smooth as possible as it’s one of the draw cards for my small business startup.

Thank you so much for your interest and assistance. It’s just that elusive signal which preps the laser just before it fires.

We’ve got all the x and y axis signals sorted and the grbl-lpc firmware flashed onto the Cohesion3d mini board and are communicating with it via Mac and Lightburn. The machine can technically handle 400mms (as per its brand new state with the original controller). I have been using it with grbl lpc but the speed is limited to about 100mm/s. The laser cutter control unit was missing its USB key for the original controller (currently unknown) so it was bypassed with an Arduino 2560 r3 when I bought it.

Cohesion3d controller