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View Full Version : Laser losing power???



Bob Kline
10-29-2006, 7:01 PM
I've had my 25W Epilog for about a year and it only runs about an hour a week doing small jobs on Flexibrass. I've always vector cut at 100% power and 70% speed but lately I've had to slow it down to 60% to get a complete cut. Does this seem like normal degradation?
Thanks

Mike Null
10-29-2006, 7:07 PM
It may be something as simple as focus. It could be material but it's not likely that it's tube degradation at this stage.

Sometimes the material is not as flat as you think and can cause what you're describing.

Dave Jones
10-29-2006, 7:41 PM
Do you clean your lens and mirrors regularly? If they get coated with smoke they become less efficient.

Bruce Volden
10-29-2006, 10:07 PM
Do you clean your lens and mirrors regularly? If they get coated with smoke they become less efficient.



I took my 2 LMI machines into the mfgr.a year ago this month. While there I was with the tech the whole time ~ picking his brain and asking a million questions!!!! I watched in HORROR as he SCRUBBED my precious lens!!! He ravaged them with swab after swab of reagent grade acetone. Finally I told him he was scrubbing TOO hard! He laughed and told me "How would we sell any lenses if they're scrubbed, by keeping light even strokes it is impossible to totally remove all the smoke et al." I took this to mean GO FOR IT!! and since have scrubbed til clean. Mind you these machines are 11 years old now and with the original lenses.

If it is not a lens problem, you most likely have a tube going south:( Also clean the mirrors but don't "scrub" them.


Bruce

Rodne Gold
10-30-2006, 3:15 AM
Tube dgradation will normally manifest itself as either intermittient operation , no operation at all or a 1/2 power drop (as one of the RF boards fail- the next one will follow soon after normally)
As to scrubbing lenses , well thats a BIG no-no - it WILL destroy the coatings or at the very least put microscratches on em which will reduce efficiency and run the risk of burning the lenses,
Same applies to mirrors which are highly polished steel with a gold plating , microscratches will tend to reduce efficiency and lead to overheating.

Joe Pelonio
10-30-2006, 10:20 AM
Since my tube is on some airplane on the way to Colorado, I can tell you that one symptom of the tube going is lower power. In my case running all day 5-7 days a week it went from cutting 1/4" acrylic at speed 6 to speed 3 to speed 3 two passes to 1/8" speed 3 two passes within two weeks. The techs had me check for a lot of other possibilities first, including mirrors and lenses, table level, and power supply. The first tube I had go out was the intermittent thing, it was cutting random dashes instead of lines.

Mike Null
10-30-2006, 10:46 AM
Joe:

I agree with the lower power issue but in this case it would seem to be much too early, the power change is minimal, such that several other things would be more likely. I believe they've been listed earlier but the two which I would check are material (it differs from time to time, on 1/32" IPI settings vary by color for example) and focus.

Rob Bosworth
10-30-2006, 11:30 AM
A quick way to check the condition of your optics is to turn the machine on and let it run at full power for 10 minutes or more. Then open the lid and feel the backs of all the optics and mounts. If any of them are warm, you have found the culprit. A coated optic might still look OK, especially if you are standing on your head and craning your eyes to see it, but the coating could be breaking down. A scratch, a spot on the optic, or out of alignment can change the dynamics of the laser beam drastically.

Joe Pelonio
10-30-2006, 11:40 AM
Joe:

I agree with the lower power issue but in this case it would seem to be much too early, the power change is minimal, such that several other things would be more likely. I believe they've been listed earlier but the two which I would check are material (it differs from time to time, on 1/32" IPI settings vary by color for example) and focus.
I agree with you in this case, because that is a very small change, and I hope it's something simple that he can find and fix easily.