I’m cutting a simple paper liner for a box so just have an outline cut for a base and four walls with inner perforations to fold the walls up and some perforated tabs for glueing. I have imported the file as an SVG from Inkscape where I coloured the perforation lines green and the cut line black. The first cuts I made using one shape were fine then I decided to put two or four copies of the same shape on the Lightburn page. I’ve tried this by duplication the shape in inkscape, saving and importing and also by duplicating a single imported shape in Lightburn. Either way the perforations cut for all of the shapes, The outer cut line starts fine but the laser turns off after cutting of an inch or so and carries on all the way around as if it were cutting but with the laser turned off. This happens for all of the shapes but one. The final shape cuts absolutely fine with no problems at all.
I’m baffled. The original file will cut, the laser will cut, Lightburn will send a successful file - but it just won’t cut multiple copies of the same file (although it will cut the perforation lines for multiple copies)
I’m stumped. I’ve been having a pretty successful start to my laser cutting and have made a few mistakes but been able to figure out the problem until now although I have had the occasional line which hasn’t cut amongst a whole load of lines which have cut fine. Any advice about what could be causing such odd behaviour or how to start trouble shooting it would be much appreciated.
Many thanks
Ian
Playing with this some more I thought that it was tending to successfully cut the last shape (although when I moved the shapes around it sometimes cut the first and failed to cut the second). What has made a difference though is turning off Optimize Cut Path. With that off it cut everything but in a slightly round-about way. So I have some settings to look at and try to understand. If anyone has experience of Optimize Cut Path creating problems I’m all ears 
Ta
You may have an unusual setting in your lbrn file.
You can upload it for us to look at by dragging into the reply box or using the up-arrow in the reply box to upload it.
Many thanks John - apologies for the delay - I’ve been doing so many things and most of the laser cut things have been working. Here I made a tiny box tray to cut out of paper. It worked flawlessly. Then I duplicated it, changed the sizes slightly and put in a little finger hole to make a lid to slide down over the box tray. It cuts the fold lines fine but then gets to the outer cut and as soon as it reaches the finger hole the laser switches off and it completes the whole path perfectly - just with the laser off. I’ve turned off “optimize cut path” with no effect, I’ve turned the box 90 degrees, changed the cut settings slightly - all to no effect - it still cuts off when it reaches that point and the laser stays off for the rest of the “cut”. Any suggestions would be most welcome. Mostly I’ve found the laser, designing in Inkscape and printing via Lightburn to be fabulously easy and any errors have been me forgetting to focus, change settings etc, but this one really has me stumped and is so frustrating - I’m doing everything just the same and it’s not working!
Many thanks for any help you or anyone else can offer.
All the best
Ian
Box which doesn’t burn!.lbrn2 (11.6 KB)
I see nothing in your file that would do this. For clarification, the laser goes dark (no light) at about the point of one of the indentations in the rectangle? I assume that’s top.
I would try to repeat this and capture the console stream.
In the Console window there’s a switch on the right hand side.
It says “Show all” - click that so it’s green.
run the job. When LightBurn finishes, open a text file in windows.
in the LightBurn Console window type the following
ctrl A
ctrl C
then click over to your new text document and type
ctrl V
then save the file.
Please upload that file here. I don’t see why this doesn’t work.
Once that file is here and there’s no risk of the g-force / impact sensor losing your data - repeat the project and wiggle both ends of the cable running between the controller board and the laser engraver head (one end at a time).
hopefully it’s as simple as a tired connector or a loose wire and it suddenly starts working. Either way, I’m looking forward to a file to examine.
Console Records with notes.txt (17.0 KB)
Thanks for that John, and thanks for your detail in explaining the steps to take - I’m not sure I would have worked out that I can simply drop a file onto the window to upload it - handy.
The attached text doc has more than one cut in it. It is annotated but in a nutshell the first time I tried it it cut perfectly. Then I turned on Choose Best Direction and Reduce Travel Moves and it went back to the behaviour I recognised with the laser turning off at the start of the finger hole and staying off whilst the head methodically traced the correct path. I fiddled a bit and found it was Reduce Travel Moves which it didn’t like. I did a couple of cuts where I hit Stop as soon as the laser turned off to try to narrow down the moment the problem occurred and have included them.
Finally I turned everything in Otimise Cut Path off except for Reduce Travel Moves. That gave a whole new behaviour. It started to cut, the laser turned off whilst it continued to travel then it moved up to the top right corner and the laser turned on again and completed the cut. Turning off and then turning on again is a new one!
I think that by turning off Reduce Travel Moves I can get it to cut which is a jolly good start. But I would be interested to know what is going on and whether there is a way I can create files which don’t have this strange behaviour.
All the best
Ian
Oh - and I’m working on the assumption that it’s not a loose connection problem. There are files which consistently print fine and files which consistently don’t so I’m pretty convinced it’s something in the way specific files are being interpreted which is causing the machine to act oddly. If it was a loose connection I’d expect it to just happen pretty haphazardly rather than on specific files. I think each time it’s been a file where I have cut a path in inkscape and I suspect there is something I’m doing in that process which is then causing a problem.
This topic was automatically closed 30 days after the last reply. New replies are no longer allowed.