Currently running (Licensed) V1.7.01 on an Atomstack manufactured A20 Pro. Computer is a Lenovo M900 Mini running Windows 10 Professional and has had all the current updates to Win 10. The last 1 or 2 updates to Lightburn have created a minor problem and I don’t know if I accidentally changed something or if it’s a bug in the software.
Prior to this, (my honeycomb bed is 400 x 400mm and the work center was set to 200 x 200 (this was always accurate until the last one or two updates in Lightburn). Now, the vertical center is still @200, but the horizontal center (even though set to 200) in Lightburn winds up being 190mm and it is VERY consistent. I use 300 x 300 mm plywood sheets for most things I cut/engrave and getting images/text engravings positioned accurately has recently become a problem where I have to move them up in the grid by 10mm to keep from running off the bottom edge of the work material. I don’t know if this is a bug in one of the last couple of releases, or something I either set wrong or didn’t set after the upgrades which didn’t always pick up on my prior settings.
Thanks for any help.
How is this set/determined? In other words, how are you finding center?
By telling the software to position the laser at the point of origin which is set to 200/200. It always did before and was right on the 200 horizontal and vertical markings of the honeycomb bed which I have CAREFULLY aligned with the actual bed of the A20 Pro. It was totally accurate in all other versions of Lightburn from day one until either the last one or the update prior to that. Even in the public “beta” versions of the update it worked properly. I have NOT changed any settings since then that I know of.
In the move tab, click get position, what does it report?
Tim,
When I use “Go To Origin” it goes to 200 x and 190 Y. The Move tab says 200 x 200 so does the “Show Last Position” tab in the “Laser” window. Oh yes, when I first connect and the laser homes, it goes to the lower left corner and everything shows 0 x 0 which correctly corresponds to the laser’s position at that time. It’s when I tell it to go somewhere else that the physical X coordinate is 10mm lower than specified and shown in the software.
Just trying to get an understanding of exactly what’s happening since I’m not physically there to see it and can only rely on your description.
How have you determined that it’s at 190, by measuring the resulting cut?
What happens when you tell the laser to go to 10,10? Does it move 10mm in each direction or does it only move in the X?
What about 400,400, is it still off by 10, or is it now off by 20?
It’s still off by 10. Goes to x 10 zero y when set to x10 y 10 and x 400 y 390 when set to 400 400.
I HAVE carefully checked the honeycomb to make sure it hasn’t moved since I first mounted it. It’s still where it was when it worked properly. This has been kind of perplexing since I haven’t changed anything and it’s just started happening. I’m not sure how to fix this though I can offset my layouts accordingly to compensate for the problem if we can’t find a solution.
The coordinates you see in LightBurn come directly from the controller, so when LightBurn reports 200 mm with the laser head positioned at 190 mm, that’s what the controller told it.
Which suggests the loose-and-floppy cable from the laser head to the side rail has changed position and moved the physical home position.
The assembly manual doesn’t show mechanical home switches, which suggests the controller detects the home position electrically through the stepper drivers, which means it’s sensitive to any change in the forces near the home position. A twist in the cable, a shift in a cable tie, anything like that can change the home position.
With the power off, push the laser head toward the home position while watching the cable movement. Look (and feel) for anything that can (or could) interfere with the head motion; that’s where the trouble lies.
Regrettably, in the consumer laser market, “factory assembled” is not synonymous with “correctly assembled”. Based on some horror stories you’ll find around here, you cannot assume what came out of the box was put together with any attention to detail.
OK, I think ednisley may be on to something. Use the controls and go to x 200 and Y 400, then click you go to origin and see if you are now physically at Y 210 or Y 190. If at 210, that confirms slop in your Y belt/axis.
Tim and Ed, THANKS! That got it. Wasn’t loose or sloppy but my limit switches are optical and I had not cleaned the lenses on them. They were very dusty! A good cleaning fixed the problem! Live and learn.
Again, THANKS! A bit of sleuthing and I learned something else new about this stuff.
Yay! Sometimes it just takes a fresh perspective.
Bingo!
Optical sensors sidestep damage to the actuator arms on mechanical switches, but putting optical switches in a machine throwing off vast clouds of dust / fumes seems like a Bad Idea™.
T.I.L.: another horror story. 
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