Loss of Power?

[daniel coyle]

I have a 130-150 W Sinjoe Laser. It will not cut through 1/4 " cardboard at 60% power (not even after a second pass) and it will not cut through 1/4" wood, period. Not sure it would get through 1/8" wood actually.
It is about 3 years old but does not really have that much use. Maybe a dozen hours a month on average?
The lenses and mirrors seem clean and in decent shape and I am running it up to 30 mA. It used to cut OK, not amazing, but way better than this. The change does not seem particularly gradual. The water cooler has always worked and is tied into the on switch so I can't forget it.
Any ideas, necessary information I am leaving out or recommendations? I searched the forum for a bit but didn't get to anything similar (thought there must be lots of this)

[Jerome Stanek]

30 ma is high for that watt tube my 130 watt recommends no higher then 25 ma for the longest life. you may have killed it running it that high

[daniel coyle]

Is there a way to diagnose this and know the tube is actually the problem before buying a new one?

[Bill George]

I am not here to tell you to order a new tube, but if your power supply is outputting 30 ma I think that would perhaps rule out that. The rest is up to you. You might do some searching for a way to test your power supply.

[daniel coyle]

Bill, thanks. Just to be clear you're saying that being able to output 30 milliamps is a sign that the power supply is probably not the problem, correct?

[Kev Williams]

Have you checked the beam alignment? If not, you should-
But as a quick check before going to that trouble, does the lens have a nose cone?
If yes, remove it and see if you gain any cutting power--
If yes, you're beam is hitting the cone-- and could be hitting other things it shouldn't as well

[daniel coyle]

Thanks Kev. I know what you are saying and I will check it again.

[Bill George]

Thanks Kev. I know what you are saying and I will check it again.

I am assuming you checked the mirror alignment and lens as you said you did in your first post? Masking tape over the mirrors one by one to make sure they are correctly aligned?

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[daniel coyle]

I had not been that thorough, just had checked the nose cone (as Kev had suggested) and the cleanliness of the lens and mirrors. I checked the nose cone situation again and, alas, the laser seems perfectly focused through the nozzle and when I remove the cone the ability of the laser, even when I turn it up to 25mA, to penetrate is just almost negligible. It could cut paper but it can only etch cork or wood. I will check the mirrors with tape nonetheless and make sure nothing weird is going on there. They came adjusted and I have never moved them or the machine so I am certainly expecting that, given the perfect focus at the nozzle, the mirrors will tell me the beam is aligned still. But I have said that sort of thing before of course.

[Bill George]

Its a standard Chinese laser import is it not? Expect anything when your troubleshooting, the worst thing you can do is assume.

[daniel coyle]

20180915_125211.jpg
so i did the tape test. left most is from tube to mirror 1, mirror 1 to 2 and then mirror 2 ro 3. I cleaned the mirrors with alcohol swabs before testing by pulsing at 2mA. all the burns were roughly centered and they created an end beam that exits the nozzle cleanly. new tube?

[daniel coyle]

FYI, one month later. I DID end up purchasing a new tube, not 100% sure that this was the problem but having attempted as much diagnostics as I had in me. The new RECI tube cost me $1300 with shipping from Lightobjects in California and, now installed, seems to show that the tube was the problem. Cutting is much improved at 20mA.

Having a little bit of trouble getting the new tube focused through the laser head. Considering drilling out the end of the head to make the aperture just a little larger as I just can't seem to reliably get the same cutting with the head on as I do with the head off (pretty close but still probably only 85%?)