Weird problem with K40 X axis
Hi, I have suddenly started having problems with my K40, if I try to engrave an outline (in line mode) it seems to work normally, but if I use fill mode the X axis goes crazy, sometimes it starts normally then shoots left and right at random. I have tried adjusting the tension on the X axis belt but it made no difference. (thinking maybe a worn belt, but the machine has not had heavy use)
Not sure if the problem is hardware or software, using the Amazing Tech Mini Gerbil 3 controller.
Video here https://drive.google.com/file/d/1J6ws2zRpXwzxGSPCLmPCLhqBa6RO5WV-/view?usp=drive_link
First engraving ABC in line mode, then the same in fill mode (video stopped after a few seconds, but just more of the same!)
Nothing has been changed in hardware or software, using the latest version of Lightburn, worked fine one day useless the next.
Any ideas?
Hi Alan,
I have never seen this weird behaviour before. Have Window been upgraded? Is the USB cable or comms being distorted via a power cable? Some ppl route their USB cable through the laser tube compartment which of course causes major comms distortion.
Maybe try lines first as a complete cycle than run a fill cycle. I think line and fill combined might have caused a problem (Lightburn g code might be at fault).
Pls let me know if that made a difference.
Thx Paul
USB cable is well away from the tube, I just tried a job with a filled circle and some text in the middle, turned off fast white space, scan speed about 50 mm/sec, worked perfectly until about half way through the job then made a "clunk" sound and everything moved to the right and distorted. Seems like something is slipping in the X direction. New belt on order, when it arrives I will take the gantry out, give everything a good clean and a drop of thin oil. If that doesn't work I'm not sure what to try next. (I am 90% sure the problem is mechanical rather than electrical)
Thanks Alan,
I've subscribed to this topic now as well as keen to see it fixed for you.
Noting for future reference that current lightburn version is 2.0.03
Alan, another thing you could try is going back to a previous lightburn version, see downloads page:
https://lightburnsoftware.com/pages/download-trial
Regards,
Dan
Hi,
I don't think the Lightburn version is the problem, I have been using V2.0.0.3 since it came out and only had the problem a few days ago, as far as I know nothing on my system has changed (hardware and software). When the new belt arrives I will remove, clean and lubricate all the moving parts. The really frustrating part about this is that it sometimes works, but failing halfway through a job is really annoying!
ok, am still puzzling over this.
Is the desired test image simply just ABC filled in? If so, I notice:
- The y position of the laser jumps down
- Subsequent movements along the X axis are not matched with meaningful movements on the Y axis. So rather than an x axis problem, I think the Y axis could be the issue.
- The X axis burning goes wider than the original x range of the ABC, so something's going on there too.
Have you tried/could you please try slower speeds for fill mode? This would help us feel confident that it's not due to mechanical or electrical dynamics that fail at that speed.
Thanks
Dan
A quick update, I just tried a filled circle on piece of scrap card, 50mm/sec speed.
You can it start ok but after a few seconds you can hear a noise from the machine and the head moves to the right, a little later it shifts to the left.
Video here:- https://drive.google.com/file/d/1QHnKsFAL8YUhsNs6x18jIYqmSRd47aSY/view?usp=sharing
Hi, SUCCESS!!!
I reduced the X axis acceleration from 12,000 to 5000 and so far it has worked perfectly for over 5 jobs (still testing)
No idea what changed, it has been at 12000 for a long time, but at least this fix saves me from having to remove the gantry then the hassle of re aligning the mirrors!
Thanks again to everyone who made helpful suggestions 🙂
That's great, g00d 0n you Alan for your patience.
One of the things with K40's is that they are built cheap! So can be hard to find the issue when the whole design is done so cheap. We have foudn that adding anything to the x axis like a drag chain etc etc may slightly compromise its ability to accelerate quickly, maybe this applies to your machine? Appreciate that it's odd that it worked last time, maybe something is aging/wearing as well.
All the best
Dan
Yes, the thing that's aging and wearing is me!
My K40 has been heavily modified, all the electrics have been repaired (the earth/ground screw was insulated by the paint on the metalwork, and the crimped connections on the wires just pulled straight out!) I improved the extraction, replaced the mirrors and laser head and of course the best upgrade was the MG3 control board!