Several times my Twotrees TS2 (541 x 541 mm) stops while burning with the following message:
Hard limit triggered. The machine position is likely lost due to a sudden and immediate stop. Repatriation is strongly recommended.
On or near line 358127 (or on an other test : On or near line 393385)
Interrupted work
It’s very frustrating because in this case my acrylic support is ruined because the canvas is half engraved, and I have to start the engraving operation from the beginning.
That means you triggered one of the limit switches due to over travel.
You should not get this as long as you meet the following conditions:
Home your laser at the start of every session
Never move your laser head manually. Use jogging controls exclusively
Do not ignore any warning messages from LightBurn
Additionally, this is simplified if you use Absolute Coords for your Start From mode in Laser window.
Separate question, is there a reason why you’re doing a vertical scan? Vertical scans on gantry machines require movement of much more mass than horizontal scans. You’re almost certainly not getting anywhere close to the requested speeds for your job.
In addition to PY’s comment, I’d like to add that if you are confident you didn’t hit the frame at that point in time, your limit switches might have been activated due to either a loose plug or electrical interference. Check the switches closely and make sure all cables are tight.
Concerning your separate question: “Is there a reason you are doing vertical analysis”
Answer:
The reason why I am doing a vertical analysis corresponds to a test, because my first attempts at horizontal scanning on this photo made the straight lines appear distorted,
as if the back and forth of the laser head did not make it possible to make lines. perfectly aligned straight lines. So I tried horizontal scanning to minimize these vertical line distortions.
But if I engrave a rectangle, or vertical lines with the Lightburn drawing tool, they are perfectly straight !!!
It’s as if the engraver draws vector shapes correctly, but cannot draw bitmap images correctly.
See below an example:
I think I have resolved the “Hard limit triggered” error regarding the following message:
Your Grbl may not support Variable Power mode (M4)
If your laser does not turn off between cuts,
switch to the GRBL-M3 device
[MSG:‘$H’|‘$X’ to unlock]
[MSG:Caution: Unlocked]
ok
I re-configured my TS2 as GRBL-M3 instead of GRBL
No more problems, apart from the vertical lines which are still not straight.
This mode should not be related to the hard limit triggered in any way.
This is likely a false positive message from LightBurn due to not recognizing the version number from the controller. TS2 is almost certainly going to have a firmware at least 1.1f.
Using GRBL-M3 will lose the ability to have variable power which will have a negative effect on your ability to mitigate overburned areas.
Run this in Console to determine your GRBL version:
$I
The artifacts in the image are likely either a mechanical issue or a firmware problem. Are you saying that if you create a large filled rectangle that you don’t see these issues at all?
That’s a 32bit machine, you should definitely set it to grbl instead of grbl-m3. You are cutting major advantages of the newer versions. Additionally, the s-value max might have changed to 255 if you changed to m3, then you are only using 25% power maximum.
Melvin is on the mark. I suspect it’s the odd format of the version number that’s throwing LightBurn off and providing the warning. It can be safely ignored.
The problem isn’t likely to originate in the design. I assume the photo that you showed with the wavy vertical lines looked straight in LightBurn.
If you take that large rectangle, set it to fill, then burn it to a material, what do the results look like?
As you advised me, I did a test on 3mm cardboard (see image below). A larger and thinner rectangle, the rendering of the vertical lines is perfect. So is it really a bitmap problem when I try to burn a black and white photo !!!.
I have just made a test grid on canvas cardboard, covered with two layers of white acrylic, then with a layer of black acrylic.
The best rendering indicated by this grid seems to be Speed=4000 mm/mn, Power=40% (see photo below). Following these criteria, I restart a complete engraving of my cathedral photo (estimated time 7h30). I’m waiting for the result.
