Sainsmart RYC-GRBL-V2 board trouble-shooting

A friend recently gave me a laser unit he had kind of ‘cobbled’ together. It’s a Solidoodle 3D printer mechanism with some 3D printed laser mounting bits and a Sainsmart RYC-GRBL-V2 controller board.

I have a CNC machine in the shop that I drive with LinuxCNC and so - having the computer, I downloaded LightBurn, installed and played. But… life got in the way, my trial expired and this weekend I was back to trying to get this thing to work. I downloaded a Windows version of LightBurn to my laptop and have been using the trial on that one to play (yes - I know… I’m cheating on the trial… the $40 license fee is not going to be a problem - if I can get this laser to produce something I want. So my apologies to LightBurn’s authors - I truly am not trying to defeat or otherwise cheat them out of their deserved license).

Anyways - back to the problem. It was ‘cobbled’ together… the limit switches were not wired in and the stepper motor connectors made intermittent connections. I got so frustrated yesterday that I ordered the proper connectors for steppers and limit switches (gotta love Amazon ‘next day’) and I just finished wiring them in. The ONLY wires I didn’t change were the laser connectors - they were well fitted and functional.

Today - after redoing the wiring, the steppers work consistent, but I can’t get the laser to fire and I can’t get Lightburn to ‘recognize’ the limit switches. ‘Homing’ won’t work.

I’m familiar enough with G-Code from my CNC to understand how to enter and drive the motion. What is the G-Code to fire the laser? I suspect it may be a complex ‘statement’ including a power factor.

I tested the laser directly and it is fine - I just found the Sainsmart manual for the board - but it really isn’t terribly helpful (not trouble-shooting steps). I’m getting annoyed with all the ‘fixing’ - I want to BURN something!!


Thanks folks - appreciate any advice provided.


This is a controller configuration issue. You have to tell the grbl board you have limit switches for it to use. You can find the configuration in the Edit → Machine Settings. Or use the $$ at the grbl prompt.

You probably want to check $21, $22 and $23 for the correct values for your machine and setup. In fact is this is like most of the CNC machines your configuration for speed of the head will be different. Save your current in case you need it before changing anything… :slight_smile:

Here is a link to an older copy of the grbl settings.

It’s missing the $30 some odd settings. These are covered in the Lightburn GRBL setup guide.

You can google this for more information.

Good luck :slight_smile:

Figured out the laser (like I said - this system was ‘cobbled’ together - so the laser connector had to be inserted ‘against’ the keying mechanism).

Figured out the limit switches (they are NC switches and the board was looking for NO). But I’m still not able to ‘home’ the system completely.

My next step is to see if anyone knows if (and how) I can upgrade the GRBL firmware on the board. It’s not a simple Arduino Uno with stepper shields - it’s a custom board based on the Atmega328 - so I THINK I should be able to just load new firmware… but I’m not an Arduino genius.

I have a couple more questions - but they need to be posted separately…

Thanks for all the ‘looks’… and for the suggestion Jack!


The Arduino is an Atmega328 it’s in a different 28 pin configuration, but pretty much the same animal.

Try this link addressing the Sainsmart was the first hit on “firmware upgrade Sainsmart RYC-GRBL-V2” on a internet search inquiry.

See if that make sense. Don’t upgrade until you understand the process, also make sure you make a backup of the $$ configuration :smile_cat:


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