Universal Laser is suddenly rastering a double-image!?

[Scott Balboa]

Good morning everyone...

I am hoping someone might have a few helpful ideas they can share while I troubleshoot our laser this morning. I have tried to run a few jobs and keep getting a double-image -- as if you copy/pasted the word "TEST" and bumped it over about 1/8". The baseline is the same for the double-image (off on the X axis, not Y axis). We have a Universal Laser 40w machine, 2 years old, and never had any problems save for the occasional need to reinstall the driver, on the software end. I have already tried shutting the machine off, rebooting the computer, and changing out the engraving table to make sure it's connecting correctly. I also checked the lenses, screws on the lens/cover, and did a brief clean of the belts and bearings. The laser was engraving great as normal up until 8pm last night, when we ran the last job - but when I opened shop this morning this problem was suddenly here to greet me.

We have never taken apart the laser before, and I have never had to make manual adjustments to any of the hardware inside this baby since we first bought her, so it's hard to believe that overnight part of the mechanics went awry.

Has anyone experienced this or have any ideas? I will of course be calling tech support shortly, after I rule out the easy fixes. Thank you to anyone who can help.

[Scott Balboa]

I should also note that the red laser dot that is visible when the machine cover is open appears normal on the material/table, as in it doesn't look like 2 seperate dots or anything...

[Mike Mackenzie]

Scott,

What system do you have?

Clean the X rail and bearings real good you may have something on them that is causing it to skip.

Try to move the engraving to a different spot on the table and see if the results are different.

What happens if you slow down the system?

[Scott Balboa]

Thanks Mike,

We use Corel X4, to a Versal Laser 40w (not sure the model - I can look). I already tried engraving in a different spot on the table, and got the same results with no difference in the "double-image" offset. Oddly, I tried vectoring some swirl-shapes on brass and it is vectoring clean, without a double-image, so it is definitely something just with rastering...

I will try slowing it down... good idea...

[Mike Mackenzie]

Scott,

I will guess you have the VLS 3.50 system. What this sounds like to me is a bad idler pulley especially because vector is working and the problem is only with the raster.

How does the X axis feel if you move it left to right with the power off?

Does the system sound any different while rastering?

actually I would bet that the air line for the air assist is hanging up.

[Scott Balboa]

Yes that's right, it is a 3.50 -- my bad.

X axis feels just fine, and moves smoothly. It sounds normal. That is why this is so strange -- my ears don't detect anything jammed or slipping, and I know the sounds of this machine VERY well. We also do not have air assist, so that rules that out.

Upon doing another test, it seems the double-image splits the difference from where it SHOULD have engraved. Example: If I raster a 2" box within a 3" square piece of brass, each [double] image is slightly off-center, one about 1/16" to the left, one about 1/16" to the right. The engraving on both images is identical, as in each one doesn't look like it received more or less laser power.

[Scott Balboa]

Mike, I misread your comment about the air-assist hose -- I should still have one even if I don't have air assist, right? I will pull the engraving table out and look underneath, down by the belts, and see if something is down there.

[Mike Mackenzie]

Scott,

Even though you do not have air assist all of these systems are set-up with the air assist hoses. I have seen this before where the hose gets stiff from age and causes this problem.

Un fortunatly you have to remove the X axis covers to get to the air hose.

If you want to PM me your PH# I can explain to you what you should do.

[Scott Balboa]

Thanks Mike, I will probably take you up on that. The owner wants to come down here before I proceed any further... so I'll be in touch. I appreciate the help, a lot.

[Paul Brinkmeyer]

Have you tried to shut laser and computer off and then back on.
This has fixed mine when it happens.
Factory thinks that the memory in my laser needs to be re-flashed,
But I have not done that yet.

[Chuck Stone]

I wonder if a mirror has come loose. It can flop to one side when the carriage moves
one way, and then flop to the other side when it goes back. That will put the image in two
different places .. one for each pass of the head, offset because the mirror moves.

Also, if there are roller bearings on the bottom side of the head (I don't know that machine)
and one has come loose, it is possible for the head to 'rock' as it goes back and forth. The
bottom bearings should stop that from happening, but only if they're properly tightened.

[Paul Brinkmeyer]

If you look at the images under magnification you can see if they are perfect duplicates without any missing parts.
If they are perfect images, it more than likely is just that, 2 images being sent by the laser.
I have gone back after rebooting the laser and sent a file from the control panel that has had double images work OK and only send one image after the reboot.

Physical problems would leave parts off of one image and place them in what looks like a second image.
You will have two images that are missing parts. if this is the case, then start looking for bearings, belts, etc.

[Scott Balboa]

PROBLEM SOLVED! After spending a while on the phone with a ULS tech, and after trouble-shooting just about everything, we were told it most likely was one of the belts/bearings/motors. They highly recommended we replace some of the parts as part of a regular maintenance schedule, but first we installed the newest updated driver -- and voila, it fixed the double-image problem! Even the guys at ULS seemed surprised it was a driver issue, because everyone up until this point was convinced it was hardware-related. Thank you to the folks here who were willing to help -- luckily everything worked out!