Ghost lines raster and vector

[Helen Cast]

The attached photo shows what's happening when cutting (all the time) and engraving (some of the time). The machine is one of the 100 watt Chinese Orion (OME, OMX) that has worked well for 2 years.
The mirrors have been cleaned and alignment testing is right on center. It's happening on various materials so it's not specific to material. Air assist is on. Can anyone let me know what might be the issue please?
Thanks!

[Kev Williams]

Somewhere in the beam path the incident beam is reflecting off something. I just went thru this with my LS900, ever since I re-installed the tube after Evergreen rebuilt it.. when cutting I'll sometimes lay my arms across the top of the machine while leaning in watching it cut (my door is always open, and I don't suggest anyone else do this ;) )- and with the gantry between 4" down and full down, I was feeling heat hitting my right arm. I traced the problem to my beam was hitting the last mirror just a snick high and right, and part of the beam was hitting the top-right part of the mirror's frame, which is beveled above and below; the beveled top edge of the frame is basically straight up & down, and what little bit of beam was hitting that flat spot was reflecting straight back to my arm! It wasn't a great deal of heat but definitely noticeable. I was able to tweak the 2nd to last mirror slightly and got the beam to hit real close to dead center, and I do have a better cut now and no heat hitting my arm!

If your mirrors are definitely lined up good, then 2 things: First, do you have a noze-cone 'nozzle' on the end of your lens? If so, remove it, and see if you lose the ghost- if so, there you go :)

If that doesn't work, then the next possibility, is something may be burned onto one of the mirrors, the lens, or the laser tube's snout lens, OR a very small crack in one of them, which is causing the beam to split slightly, resulting in 2 focused points of light onto the work...

I've found burnt up bugs welded to the top of one of my fiber's lens twice, and this fly got a wing lasered off in my LS900 while walking around inside while cutting, so anything's possible!)
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[Bert Kemp]

Kev I don't know how you do it, you work 16 hrs a day and still find time to solve everyone else's problems. You 've help me out more times then I can count. I'm sure everyone here appreciates your knowledge and your willingness to share it.Thanks Kev your 1 in a Million :)

[Mike Null]

Amen to that!!!!

[Helen Cast]

Hi Kev - I very much appreciate your input and will be able to work on the machine this afternoon and will report back when the issue is solved - hopefully - today. Many thanks for the help!

[Bert Kemp]

Wonder if she ever got it figured out?

[Helen Cast]

Hi Bert - Actually, no. I'm still running tests to determine why it persists even after checking alignment and cleaning/inspecting mirrors. I can't see the exit glass on the tube itself so removing it will be next. I was out of town for several days so I'm just getting back to the task. I'll be back with more questions IF I can't figure it out. Thanks!

[Bert Kemp]

Must still be running test:eek:

[Helen Cast]

Must still be running test:eek:
I'm still waiting on a new focus lens to arrive. After cleaning the mirrors and lens again it seems the focus lens has a 2mm burn circle off center that is easy to see with a magnifier. I'm hoping the new one (if it ever gets here) resolves the ghosting.
In the meantime, the machine is having another vacation.

[Helen Cast]

UPDATE: I changed the focus lens and got a bit sharper line but am still getting the ghost lines no matter where the head is on the table. Please see picture. Next are the 3 mirrors that are supposed to be here today. As for the focus tube cone - it's an integral part of the lens holder so you can't remove it. I could drill the orifice out some IF the beam is hitting the cone. I'm not sure if it is or not since the laser is working - maybe only at 70% efficiency. Could this be a simple mirror issue?
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[Bert Kemp]

I suppose if you had a hairline crack in a mirror it might cause this not sure.I'm not sure why you can't remove the cone, maybe order a whole new tube and cone , their not expensive

[Helen Cast]

I suppose if you had a hairline crack in a mirror it might cause this not sure.I'm not sure why you can't remove the cone, maybe order a whole new tube and cone , their not expensive
I meant the cone comes off but it holds the lens in place so the machine can't function properly without a cone attached. I/ll inspect the mirrors again but either way I'm replacing them today.

[Bert Kemp]

I would cut a part of the cone off470031

[Kev Williams]

If you haven't already, remove the cone, place a slab of blue painters tape over the opening, and test fire the laser -lightly-, just enough to turn the tape white if possible. Or, a burn hole is okay, main thing is, the beam coming out the tube should be real close to dead center. The lens will help center it after the fact, but if it's off quite a bit, the beam WILL be hitting the cone...

I wish they'd just put an air line onto the lens head rather than pumping the air thru the cone. I have 3 'spendy' lasers and 1 Chinese laser, and none of the spendy lasers ever had a cone tip...

[Helen Cast]

I readjusted all 3 mirrors (3rd time) and centered the focus lens tube for vertical instead of replacing mirrors (they are delayed in shipping) - Well, it is cutting and engraving pretty well for now! I think the beam may have been hitting the cone ever so slightly so tweaking the head assembly for vertical is critical.
There is a 1mm scratch on mirror 2 so I'll change it when the mirrors arrive. I agree putting the air on the cone is not smart design. Still, this 100 watt Chinese laser has worked pretty well for a few years considering it's price. I used to have an Accuris so this OMTech is a step up for me. Someday it would be nice to have a more powerful BOSS Laser or even better yet a KERN Laser from right here in Minnesota. My new toy is a Crossfire Pro CNC plasma table/cutter. A bit more challenging on the learning curve than the laser but cuts almost any ferrous/non-ferrous metal so far up to 1" thick.
Many thanks to you all for the guidance!! HAPPY HOLIDAY SEASON to you ALL! I'm sure I'll be back with more issues before too long.

[Bert Kemp]

glad your up and running again :)