A GRBL compatible controller board is required. The lowest cost is
an Arduino UNO with a CNC shield for $12 (Ebay), but a single board
card with onboard relay and laser control is available for $35 (Ebay).
The small stepper drivers would be replaced with external
driver boards for $2.95 (Zyltech) This allows the controls to
run higher amperage and voltage external stepper drivers.
The preferred stepper driver is a DM542 for $17.95 (Zyltech)
The preferred stepper motor is a nema 23 269in-oz 3
amp motor for $17.95 (Zyltech)
24V power supply $24.95 (Zyltech)
An alternative to wiring the controller to the motors is to buy the
Openbuilds Black Box for $150. The power supply is still required.
CNC CLUB OPEN SOURCE DIY ROUTER PROJECT