CNC drawing machine - Newbie needs help please

Hey guys, so during isolation i decided to trowl youtube and find something to do with my arduino uno thats been sitting in a drawer for 2 years.

been on youtube and followed this vid (

i have most of the hardware, im using 2 drives and a servo as the x-axis instead of a 3rd disc drive and instead of using the seperate servo controllers i have a servo/motor shield sitting here.

now my issue is the servo/motor shield i have is obviously different pin outs for the steppers in the HEX code. the problem i have is I cant program or code at all.... I can read it and sort of get by but honestly its a different language to me.

Im using the Hex code off GRBL ( and inputting it with the Xloader Everything uploads smoothly there but obviously nothing happens when i run the gcode as my hardware isnt configured correctly.

any able to help change my pinouts or the hex code for this shield?


I’m not at all clear about what your problem is and I am not prepared to watch a 23 minute video.

Start by telling us what stepper motor drivers you are using.

GRBL is intended to work with a GRBL shield and GRBL is a very complex program so I suspect it would be a major achievement to modify it to work with a strange shield.

Also, GRBL is written to work with stepper motor drivers (such as the A4988) that take step and direction signals. AFAIK it will not work with H-bridge drivers that need signals of 4 I/O lines. Controlling a motor through a h-bridge imposes a much greater computation load on the Arduino.

Conceivably if you have a second Arduino you could program it to pretend to be a GRBL compatible driver to act as a go-between between GRBL and your servo/motor shield. It would be an interesting challenge, but not simple, and you would probably need a Mega for the go-between to have enough spare I/O pins.