Trotec MOPA issues

[Eric Allen]

We've had issues with our galvo laser dropping parts of marks if we run faster than 1 part per minute with a 3 second run time on each part. It doesn't start happening until after 5 to 10 parts. Sorry I don't have pics at the moment, but for reference it tends to loose things like the right leg of the letter "R" and "A". Those are just examples, we've lost the right side of the top leg of a "5" as well, and it drops more info in different locations the longer we run. It usually starts with one character and we loose more of that one and additional characters. We've had to program in a 35-45 second delay between firings to prevent this. To me, it's seems like something is getting hot, like a power supply not putting out enough oomph per part. The vendor has suggested a setting adjustment related to when it fires, we're both old and have forgotten the name, it's something like lasermatch, but to me that seems off because that's usually an issue from the first firing if you have it. We have an old Epilog that we have to use that adjustment on when we run fast, most likely because of mechanical slop, and back it off running slow. That happens from the very first part, so I think we're about to run down a rabbit hole that is the wrong direction. Anyone have similar issues with these Austrian / German systems and a better direction?

[Kev Williams]

just some suggestions:

--get a can of electronics cleaner spray. I really like this CRC Lectro-Motive spray,
because it's completely immune from powered-on electric stuff. I actually spray
the stuff right into my Bodine engraving machine motors while they're running
to blast the brushes carbon-soot out of them.
lectramotive.jpg

--try replacing your USB cable, and spray the new cable connectors and the ports they plug into--

--if you have access to Trotec's galvo scanhead's cable, unplug it,
spray the cable & scanhead connections and reconnect--

--if you're okay with getting inside the cabinet, find any and all connectors
attached to the controller card, inspect the soldering, unplug spray and reconnect them all-

My first fiber, not long after I got it started engraving like this;
the lower one is okay but not the upper!
DSC05779.jpg

The garbled N/A was a different-hatch & color 'cleanup' pass,
which was supposed to align with the 'good' one...
DSC05795b.jpg

--I pulled the controller plug, unscrewed it's cover, and didn't like the solder
job I saw, so I just 're-cooked' all the soldered spots with my iron. Triumph
replaced the scanhead on warranty just to be sure about 2 months afterward,
but it never did mess up after my 'repairs'...

In my over 40 years dealing with computer controlled engraving machines and lasers,
I haven't had many electrical issues to speak of *knock on my head!* , but of the
issues I've had, dirty or bad cables has been the problem over 90% of the time...

--also consider a totally different computer... oh yeah

[Eric Allen]

Thanks, I'll give the electronics cleaner a try, I hadn't seen that version before but it looks great I have to hold off on the other things, it's under warranty, just barely, although the computer unit came with the warranty seal already broken. That had me wondering if they sent a used unit. My issue would be more like the right bottom of the "A" leg starting to go missing, then part of the "8" starting to vanish, then some other random bit of another one and all getting subsequently worse. I can certainly see where a bad contact heating up could cause the issue. No real distortion like yours, just stuff starts to go missing leading me to think it isn't getting up to power between shots or something is resisting power flow. It just reeks of power supply weakness to me. I'd like to get under the hood of everything with a thermal camera, but I suspect that might violate the warranty Are you also a member of Uncle Sam's Motorcycle Club, or just marking for someone?

[Kev Williams]

'getting under the hood' shouldn't violate anything, since simple adjustments, such as rotary driver step and power settings, or plugging in other hardware such as auto-feed conveyors, require opening the hood
--But good idea to check with Trotec first!

Fiber lasers, at least the Chinese versions like mine, have several sets of user-adjustable settings that determine when the laser starts and stops firing; if the laser starts 'late' it could leave blank spots, if it stops late it could over-run the last engraving process-- I'm not so good at explaining it all, but the jist is, the galvo mirrors move SO fast that the laser's timing must be set just right...

So you might just need a timing adjustment? However, the fact that yours isn't 'consistent' and is seeming to require some cool-down time could definitely be an electronic bug of some kind...