Skr pro 1.2 hesitating while lasering tiles

I am attempting to laser an image on a tile, and I can visually see the x axis stutter while it runs, and I can see it in the end result. I don’t see any hesitation normally, and I’m wondering if maybe using the tft sd card with a old junky as card is the problem. This seems unlikely though because it really isn’t that much data. Any ideas why it would hesitate? I’m using the g commands to control the laser (G Sxxx).

I also tried the latest nightly firmware, but it appeared to reverse some of the axises, so I quickly reverted. Maybe I should try again and swap the motors.

Are you using Marlin or GRBL? If you have not selected laser mode then every time you send a different Sxxx the machine will pause for the ‘spindle’ to get to the new speed…this will cause the laser head to stutter.

I’m using the v1 Marlin build. Is there a grbl version that works for the skr pro 1.2? I didn’t think there was. When you say laser mode, do you need to recompile the firmware to always be in laser mode, or is there a g command to do that?

He’s talking about grbl. grbl does not support 32 bit boards (except for the grbl_esp32 fork).

The latest firmware has some of that stuff fixed. I know Ryan tested it a bunch. If you can’t figure out why the axis are reversed, you could try to compare and pull the laser changes back into your version, but it is probably easier (especially long term, for future updates) to figure out what is reversing your motors in the latest builds.

I know that a change of controller and/or firmware isn’t the answer you are looking for… but I agree with Mike about Grbl’s “laser mode” ($32=1). I’m unclear as to what Marlin’s laser capabiities are today but here is a post where I compared Marlin and Grbl with the same grayscale image… and which shows the stop/start action while raster engraving of Marlin – and lack thereof with Grbl – that I’ve seen.

I have a few V1 forum posts showing a few ceramic tile engravings as well. – David

@dkj4linux - I am actually wiring up a board as I read this for GRBL. I keep finding instances where GRBL is better for use with a laser. I’m using a MKS Gen 1.4 and planning on running GRBL-Mega-5x. I already have it built with what I “think” I need. I just wish I was faster with crimpers. :slight_smile:

I’m not convinced I grabbed the correct nightly build. I looked through the diffs, and there was a lot of stuff in there that didn’t look correct to me. It does look like the latest skr pro build is failing to build:

Hmmm. I need to be more clear. The latest ones track bugfix, which does break sometimes. But when we make a change and merge it, it builds against the latest released marlin. Try this one:

I tested this one out, and I am getting the same results. I am currently using the G commands for laser control. Does this version fix the issues with the M commands for laser control?

I honestly don’t know enough about the modes to say. I have not been deep diving on this topic.

Here is a picture of the same tile printed with GRBL and Marlin. The GRBL tile is on the left and the Marlin is on the right. You can see the lines in the Marlin tile where it was pausing during the print. So far GRBL has its quirks, but I am quite happy with it and will likely focus on it going forward.

1 Like

I think that is the right move Dan, the way I look at it is Marlin is brilliant for 3D Printers but it tries to be a universal firmware that ends up being overly complicated and intricate for a simple application like laser engraving/cutting/hobbyist cnc. To each their own.

What paint did you use on the tile. Aerosol paint is soooo expensive over here in Frog land that I don’t want to waste €20 on paint that doesn’t work.

I used some rustoleam white spray paint. I can’t remember what I paid, but I want to say it was less than $4 for the can, and one can will do a lot of tiles. I bought a few different whites, and I haven’t noticed really any difference between the ones I have tried.


Yup…I said it was a silly price here. ok rustoleum is made in the USofA but aerosol spray paint of all kinds is very expensive over here for some reason… they call them 'bombe’s for a reason…they cost a bombe :slight_smile: