Laser shifting when engraving

Hi,

First of all thank you for any feedback you can provide. Please let me know if this has been posted before.

Over the last few weeks I’ve had a random issue when engraving cutting boards. The laser seems to shift horizontally and I end up with squiggly sections of the text (as in the picture).

The setting I’m using is: Sp 1000 / Pw 80 / LPI 270

I’ve used this same setting to engrave over 200 cutting boards without any issues.

I reached out to Tech Support and after that standard belt tension and laser carriage wheels checks - all checked fine, they told me that since I was not engraving in proofgrade material they were unable to provide further support.

As a test I tried using the settings for Thick Bass Plywood PG (slower speed) and this seemed to fix the problem: Sp 535 / Pw 70 / LPI 270.

Any thoughts on what may be causing this random issue and /or solutions?

Regards,

Humberto

In the example above, was this one engrave that started ok and then changed to squiggly?

Yes, it started fine (with the bottom text). Then it moved up to the larger, fancier text - about half way the engraving became squiggly and then the top portion engraved fine as well.

Any chance the laser or housing for the air assist fan was bumping into something in that section of the engrave?

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The first thing I would do is check the belt and pulleys on the gantry for missing teeth and/or debris.

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I suggest taking a piece of cardboard or cardstock and seeing if it engraves properly on something secured to the honeycomb tray. It really shouldn’t matter what was being engraved (fancy script rather than block letters) because the laser is simply going back and forth engraving precise points along the way.

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Nothing that would be obvious like bumping into the machine or any vibration source. The GF is mounted on a solid table and the exhaust is firmly secured.

GF Tech Support had me check the belts as well as I disassemble the laser carriage. I checked for missing teeth on the belts and they are fine. Everything seems to glide smoothly. I have used a small vacuum cleaner to clean debris as well as the fans (with compressed air).

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I just tried it on a piece of plywood and it now engraved fine. I guess it could have been some debri but I’m worried it may be a random issue that may repeat. Unfortunately I’ve already ruined three pieces that will be very hard to sand and recover.

I don’t think it was a random event. It was probably caused by debris or some other physical impediment that changed the movement of the printhead. If I were you, I would carry on and assume all is well.

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Your example was speed 1000 right? I think that was the culprit. Sometimes high speeds are hard for it to keep consistent movement & belt control. I’ve found slowing down (which you did using the PG setting) solves the issue. It’s popped up on the forum before.

Hopefully disassembling the carriage and belts as well as cleaning did the trick. I will come back to this thread should it happen again. Thanks for the feedback

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Yes. speed 1000. However, I’ve engraved several hundred cutting boards with this setting over several months and had no issues until about two weeks ago. After it happened then I did a Camera Calibration (first thing that came to mind) and that seemed to fix the problem until it happened again last night.

I thought the issue could be wear/tear after 1 year of use, but that was not brought up by Tech Support. Hopefully the disassembly/reassembly and cleaning solved the problem.

A temporary bit of crud in the belt that got kicked out could have been the culprit.

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My first thought was the head bumped the work. That would result in the head being misplaced from where it should be. Since there is more than one instance of misalignment It looks like the fan shroud is contacting the work multiple times.
Just to eliminate the possibility, I would lower the front door and sight along the surface of the work, and with the machine off move the head back and forth and make sure the air assist fan shroud clears the work.

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Bingo! You are correct, nailed it, thanks!

I had not noticed the air assist fan shroud goes down so much. After you suggested it, I checked and the laser assembly was bumping slightly on a guide I was using to keep the board parallel in the crumb tray!
No wonder I wasn’t having this issue on thicker boards, (which required me to remove the crumb tray and where the guide was flush with the board). This made it look like a random issue! Thanks again, I’ll sleep better tonight.

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Wow, I suggest that the air assist fan bumped something in the beginning of this thread and yet you get the Bingo?!! What am I, chopped liver? :wink:

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So sorry, I misunderstood! I just realized the fan assist is what you were talking about, my bad! You get double kudos!

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:clap: :clap: :clap: :clap:

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We all do it for the applause. :grin:

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