Engraving wrong direction

New to the forum. Quick background, have a shapeoko 3 xxl for several years and am familiar with cnc operation and software (albeit somewhat different yet similar). I have recently got a K40 and immediately went into mods. Just installed new power supplies and skr 1.3 with tmc 2209 drivers. I am using the original optical endstops. After some configuring finally got everything working as it should. Turn on the machine and load lightburn. Everything works fine. It homes and I am able jog no problems. I run the “frame” around my project and it works as it should. I hit play and it takes off in the wrong direction slamming in to the gantry rails. I have origin set at front left, job position set for current position (although I have tried all others) but no matter what I do when I actually run the project it never does it where it should, yet it will “frame” where it should. Any help would be FANTASTIC!

If the machine homes and zeros to the rear-right, you need a workspace offset to shift it to the front-left - basically the same as zeroing to the workpiece, but you’re zeroing to the entire laser area.

The simplest way to do this is to create a macro that offsets X & Y by the travel lengths of each axis, so if your machine has a 790mm square area, for example, you’d use:

G10 L2 P1 X-790 Y-790

You will also need to set $10=0 and $32=1

These are described in more detail here: Common Grbl Setups - LightBurn Software Documentation

Thanks. This is for my K40 by the way. It homes to rear-left but maybe you could help me understand something. Why would it frame around the project in the correct location? I was assuming that when I hit “frame” from lightburn laser window, thats where my job will be. Which it does go exactly where I have it laid out but when I “start” the job it goes completely different. I’ve tried several different ways but no matter I do, x axis still wants to run to the negative workspace. Last I tried was G10 L20 P1 X0 Y-195 (I have a 5mm move each way off the limits). Thanks again for all your help. I’m sure it’s something simple I’m missing

If you have a K40 running Smoothieware, assuming it’s configured properly the homing position can be rear-left and the origin is still front-left.

Clear the G10 offset (G10 L2 P1 X0 Y0) as it shouldn’t be necessary. After homing the machine, what does LightBurn report when you click ‘Get Position’? It should be x0 y200 (or whatever your y travel length is)

Yes that’s correct. Everything works as it should except for when I run the job. Home is rear left, origin is front left. After homing X0 Y200. I can set a job up and it will run a frame around it no problem. Click Start and it has a mind of it’s own. Home it again, jog it around, etc and its fine. That’s what I can’t understand.

“Has a mind of its own” in what way? If you draw a 50mm square centered in the page, then click ‘Save GCode’, post the GCode file output here.

Here it is.

; LightBurn 0.9.20
; Smoothieware device profile, absolute coords
; Bounds: X125 Y75 to X175 Y125



G00 G17 G40 G21 G54
; Cut @ 180 mm/sec, 60% power
; Layer C00
; return to user-defined finish pos
G0 X0 Y0

As far as a mind of its own, I’m just referring to the fact that it doesn’t replicate what it does when I do a trace/frame. The X axis insists on trying to go negative for some reason when I start the job.
As far as the Gcode I loaded it in gcode sender that I use for the CNC and it loads fine there. I could actually send it on a dry run

Do you have an offset programmed? I don’t know how to query that offset from Smoothieware, but you can clear it with:

G10 L2 P1 X0 Y0

I may just start over from scratch with loading firmware again and redoing my config file tomorrow. Something is obviously out of sorts. Hopefully I will pickup on something that I’ve missed today. I will definitely post back regardless

So I have played around with it for a few hours this morning and feel pretty confident that its in my x axis wiring. Something isn’t right. I have have to go over pinouts and wiring this afternoon and will confirm once its working correctly. Thanks again!

This topic was automatically closed 30 days after the last reply. New replies are no longer allowed.