Hi, I have a 1390 gantry laser and have a lot of trouble getting nice edges when cutting.
It’s like if there are steps or stairs instead of straight lines
I tried to adjust all the belts, reduce axis acceleration, reduce speed but, nothing seems to work.
Does not look the motor are loosing steps since the finish line is at the exact same place than the starting point. Dimensions are OK.
Tomorrow, I will try to post video and picture
Thanks for any help, Jeff
This kind of issue is usually related to a mechanical problem. They can be a bi**h to locate.
That would be great, we might be able to give you more assistance with this addition.
Also the age of the machine- this does not seem to match the machine in your personal info?
I just update my info, a lot has happened in the last 6 years 
Post the original image files and your LightBurn settings as well so we can take a look
Hi, here are some pictures of what I was talking about. The belts look like they are OK, but I don’t have any way to measure how much weight I could use on the belt and what measure I should have.
Are you using some kind of coating that you’re lasing onto the metal?
Sounds like the lps went out, then you replaced it… I’ve seen the resistor lps test and I wouldn’t do it, I’m aware of the possible 30kV that could arise without everything being correct.
The resistor should load the voltage down to some reasonable value much less than triggers your tube, in other words it should not have arced.
Does the tube glow a pinkish color when you attempt to lase with it?
Have you put a piece of tape or a target in front of m1 and see what output you’re getting.
So I hope I don’t get in trouble for commenting but is he cutting metal?
Yes appears to be.
That’s a big laser, so it’s probably possible to cut metal.. When I looked at it, I say a failure to mark with some kind of coating… My eyes lead me down a faulty path 
You think it’d be tough to use with the top covered … lol
I was thinking the same thing haha, if that’s the case then wouldn’t that be why the lines are jagged? Iv seen that happen on larger galvos that were cutting materiel that was too much for it so I thought maybe it can cut it but not cleanly?
This is a hybrid laser cutter, can cut metal up to 3mm,but you must use oxygen for cutting. The picture show 1.5mm thick stainless. This problem will also be present with wood and acrylic or any other materials. My first thought was maybe water in the compressed air, but it’s the same with a bottle of oxygen. It has 3 laser tubes for a total of 500W.
When I put tape on the tip of the nozzle, the hole is exactly at the center.
The picture or the laser cutter is from the factory. I have it for maybe 8 months and barely used it. Maybe 20 to 25 hours.
I tried to lower acc. for the X and Y axis and no improvement.
Thanks again, everyone for your comments. Jeff
How are these come together to form a single beam? Is it just a combiner?
Seems like this, in itself, could cause strange beam configurations.
It looks mechanical, but with 3 sources, I wonder…
When I scrutinized the photo, I could see it’s head was a bit odd from what I’m used to seeing.
Is there any kind of procedure to align all three tubes?
I’ve never seen one where the tubes were series to each other like this… Thanks for the information… learn something everyday.
I still feel like it’s a mechanical issue.. I’ve never used anything this large, so I can’t make too many suggestions.
…I have also never seen a 500Watt CO2 in series, consisting of 3 tubes and I am impressed. I would have thought that it was not possible to “get in” from behind, in the next tube…, but those are probably completely different tubes that I know.
However, it seems to me a bit like your problem could come from your laser head. If the structure is similar to a normal head, except for cooling, then there is a “chance” that a lens or mirror in the head is loose. It should be easy to check and rule out as a source of error.
There is an option in Lightburn for multi-tube laser. There are 3 power supply. The second and third power supply operate together so, if I want to cut 2mm veneer, I only use the tube #1 at 20%.
I think I found my problem, I was going too fast (was using the setting they gave me) was at 100mm/sec and machine was shacking a lot. I tried between 10 and 15mm/s and the cut is much more acceptable.
So instead of cutting at 100mm/s and 50%, I cut at 12mm/s at 15%.
Cutting large parts with not a lot of details is OK at high speed.
Great you found a solution. It would be great if you could keep us a little informed on the sidelines because your machine is very interesting and impressive.
What would you like to see
I’m just a beginner in this field. I have a machine shop with CNC machine and doing it for more than 30 years, I learned SolidWorks and Master cam for drawing and programming, and I’m learning Lightburn when I have some free time.
Another problem I have is when I import DXF files in Lightburn, I can’t use lead in/out because the software will add a lead in/out at every node, so if a letter has 20 nodes, it means 20 lead in/out for cutting one letter. I’m still working on it. Jeff
By the way, I also have a 10w UV engraver.
