GRBL running on Ramps

Hello, I was not totally convinced by the use of Marlin on MPCNC (it does not interpret certain gcodes), and I discovered a version of GRBL compatible with RAMPS (GRBL 5X) is being developed. I modified the code to get the same wiring on Ramps (Autosquare include). I also have the necessary configuration of GRBL what let everything works. I am testing it with Universal Gcode sender and it works really well. Saves positions (G28-G30), all calibration plate options works and interprets most of professional programas gcodes. If you are interested in trying it, I will be happy to share it .

Regards from Spain.


I would be interested. I like the coordinates in grbl. I have a huge project list right now, but I’m sure I’ll find it useful at some point. There is a grbl for ramps already, I guess it is just old?

Yes please! :slight_smile:

I have been interested in GRBL, but the lack of auto squaring was a big no go for me.

Add me to the list of interested people.

It was something I was thinking of doing myself, but never found the time to.

On my grbl machines I wire two limit switches in series per axis. I also saw a good suggestion here to use a hard stop on one side of each axis, line it up with the endstop trigger or switch and it’s squared up.

Hi Jeffeb3, last version was published 4 mouths ago. It allows to clone the x and y axis, or a and b axis can be independient.

This is the Github link :

I have modified, cpumap.h and config.h files to change the limit pins and the spindle pwm pin.

I will upload all the files nearly. Its really important upload my grbl config for a correctly work ( you only have to change your x, y, z max travel). Or the Step/MM on z axis.



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I am interested in this also! Is the link for your modified files?

Definitely interested! I only use my MPCNC as a router and have been wanting some more big machine features, I have been considering switching controllers but GRBL on my ramps would be nice.

Bad news boys, this afternoon I have been testing the machine and there are some issues. It can´t draw circles, each axis moves in opposite directions and i´m having problems with g28 an g30 codes. Tonight i´ll try to fix it.

This is my file link:

Maybe together we can fix the problems.


Honestly I have been trying to figure out how to just interface a ramps board to a parallel port and use LinuxCNC.

Seems like an easy thing to do but surprised that no one has done it yet.

The steppers need enable, step and dir each. They need to be wired to vcc and ground and the motors. You can ignore everything else. I bet someone has, but they labelled the tutorial linuxcnc and drv8825, which is all the ramps is without an arduino.

Any movement on this?


Yes good news ! Our friend Fra589, has fixed all the problems, I´ve tested it and all works perfect. I have uploaded the new version to Drive:

This is the new link:

You only have to copy grbl folder to arduino libraries and upload the grbl example, before it clear all the eeprom with the EEPROM clear example in arduino.

When you have it uploaded I recomend to import my settings with Universal gcode sender, you only have to modify $130,$131,$132,$133 and $134 with your machine size ($133 and $134 are X2 and Y2)

All the wirings are the same, maybe you have to modify $5 to invert limit pins. The wiring scheme is in docs folder.

I hope it would be a good christmas present for all of us.



I forgot to say I´ve working with this version and a laser, to get best results the original program Image2Gcode works better than the modified MPCNC version beacause this has been designed for grbl, the movements are more fluids. The TTL range is 0-1000.


Got this loaded up on a new Mega and a Ramps 1.6 board. Finally got things to talk and even imported your settings. Seems to work in a testing type mode. No motors or ramps power connected yet. Trying to get my CAM process compatible with GRBL. I use a program called CAMBAM and have loved it. Just have to dig into post processors to strip out unsupported Gcodes

Hi, ramps 1.6 has the same pinout of ramps 1.4 so it has to work. Most of the diy CNC´s machines have grbl as their controller so it shouldn´t be a problem to work with any CAM software, for example i´m working with estlcam and Solidcam and it works really well , you only have to find the correct machine config (search a machine model wich works with grbl) like Shapeoko or carbide.


It works great. Just had to get the post processor right. Some of my old gcode files had codes that were not compatible.


Cambam has a grbl post processor. You’d be hard pressed to find any CAM program that doesn’t.

Up and running! Well in a test mode at least!

Set up a new Mega with a Ramps 1.6 board. Flashed Pablo’s files and did the import through UGS. Got some extra motors today and hooked it all up on the coffee table ( I love my wife) and look! movement and all the motors run in the correct direction.

Plan to put JST connectors on my machine and rewire it for all 5 channels. Played with files from UGS and also tested the CAMBam plugin and they both work great!

I’m glad that everything worked ok. This week I’ve testing a new program LASERGRBL, it works pretty well with this firmware to engrave pictures.


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