Laser tube problems

Hi,

Laser tube is SPT TR90. I have strange problem. When cuting starts everything is ok but then after few minutes less and less laser beam is coming out of tube. None at the end but then out from nowhere it starts to cut again for some seconds and goes off again and so on,..... Current coming to tube is all the time at 18mA. If I stop job with stop on ctrl. panel and start it after a sec then again cuting is ok for sometime. Water temp from chiller(cw-5000) is 20 C. Power supply running ok. Any idea what is going on. Thanx

Best
Mare

I've had an 80w RECI glass tube for 8 years now that's worked nicely so far - knock on my head - and, my chiller sits on the right-rear corner of the machine, which means I can't even open the back door to access the tube unless I move the chiller (which is easier said than done)--

I say that because, your problem may be the high-voltage wire to the tube may have an iffy-connection. I know they do this, but it's never happened to me, and I've never had to look at mine, so I can't tell you where to look :)

I do know the high-voltage wire is probably the smallest gauge wire, and they're infamous for not being connected all that well to the tube, and can start arcing and causing results like you're getting... Hopefully others with more experience with this problem will chime in --

What Kev said and a loose connection on the HV line may be that wire grounding or arcing but it could also be a water flow issue, or the water flow switch acting up.

Ok. Laser beam is not straight.
https://imgur.com/a/Atd8dyh
Attachment 459725

Quote:

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Originally Posted by Marc Pod

Ok. Laser beam is not straight.
https://imgur.com/a/Atd8dyh
Attachment 459725

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That's not the laser beam. That is the energized plasma in the tube that creates the laser beam. The laser beam itself is 100% invisible to the human eye. Your picture looks completely normal for what you will see in a good tube.

agreed, seems the tube's glass itself is bending the light you CAN see-