My 80 watt Co2 laser is no longer able to cut through 1/8" plywood. The wood is the same as previously cut . I am wondering if the tube is the problem or if it has to do with some of the machine settings which have been changed recently. I have never gone over 75% power in the two years I’ve had this used machine. I’m not at this on a full time basis, weeks go by with no time to work on the laser .
facts:
-laser worked fine before I had few crashes after trying to add a chuck rotary, this really screwed up the laser bed size, fortunately I had some help on this forum to resolve the problems,
finally tuned up or calibrated the axis X and Y
-laser was cutting and engraving ok until I changed the step motor on the Y axis.
after calibrating the Y axis, it would engrave ok but no longer cut 1/8" plywood
right now after two passes at .8 inch/second at 70% power on this 80 watt Co2 laser still wont cut through this 1/8 inch plywood, might take three or four cuts to go through.
The milliamp meter shows close to 25 ma power.
-I had checked the lens, cleaned the mirrors and checked the alignment, good air pressure along with extra external draw fan for exhaust.
Is my tube or power board bad ?
is there any machine settings that could cause this laser to no longer cut ?
Any hints for further troubleshooting ?
A good alignment includes checking the tem state/mode or resonance of the tube. Here is a wiki on TEM mode that include information on how it affects lasers…
I have targets I cut out and use for alignment. A target between the tube and mirror 1 (m1) works fine…
Don’t burn a hole in it. You want to see the Gaussian power distribution across the beam, so it should be dark in the center getting lighter as it reaches the outer edge. If you don’t have TEM00 then it tube replacement time.
If the tube sits on a shelf, it’s gasses are decomposing, it doesn’t have to be in use to get fail.
Thats quite a bit of good reading on wiki, I have checked the alignment on the mirrors, If I have the small burn mark in middle at the third mirror before it directs the beam to the lens, could the TEMS factor still be out of alignment ?
I re-aligned it multiple times as I had a tube on order. It went from a perfect center to this.
The result was so bad that I had to use a nozzle with a larger exit hole to prevent the beam from being blocked. Just by a resonance change… If it’s not TEM00 it will never align properly and won’t ever work like it’s supposed to.
Doesn’t tell me anything about what is really there…
This is a previous alignment target at m2, so it was two burns, short distance and far…
This forum and its moderators/diagnostic guru’s have helped me on more than one occasion so I like to report back and advise the forum viewers who have had similar issues.
My thoughts:
I thought my 80 watt CO2 laser tube was failing since I could no longer cut 1/8" ply.
I think the purchase of the AmericanPhotonics reverse alignment tool is a waste of money
the best way to align your CO2 laser mirrors is with the conventional method with min power 15%
watch the video from bearded builds CO2 laser alignments, its principles and then the actual alignment video.
I have my alignment done and it works better than before, I can cut 1/8 ply with less power. amazing
Tom
