CNC 3020/3040 change board?

[john swift]

I don't see why not if the Grbl board can work with the larger working envolope

going by the photos of 3D printers the 3018 machines they use small plug in 1A stepper drivers like these
https://www.pololu.com/product/1182



removing the stepper driver will make the step & direction signals available to operate replacement drivers that can driver the larger motors used on the 3018 machines

if the Grbl board step and direction outputs are only 3V you may need to buffer them if the new stepperdrivers need 5V pulses
( a PC printer port breakout board should do )

John

PS
which Grbl board do you have in mind ?

PPS
just found this circuit diagram for one version of a Grbl board
with plug in A4988 stepper drivers and a plug in Arduino NANO



PPPS
another Grbl board with a relay to control the spindle motor

https://simple-ee.com/2018/06/20/pro...troller-board/