[II-DALTON-II]

Hi guys, newbie to the forum but not new to laser engraving.

I have had my current machine for almost 2 years now and until this past month things have been fine. Now though the machine seems it is unable to cut straight through laminate sheet without the sheet catching on fire. To be clear, I have not changed materials supplier at all so I doubt it is a change in density or such in the material.

First it started with me having to up the cut power on my 40W machine from 28% to 40% to cut through the material. Now 40% does not cut anymore and instead leaves thick black lines and I get flames bursting up when it cuts. I tried to solve this by dropping the power back down to 30% and then 28% but I still get flames and it is still not cutting straight through. The laminate I use is 1.5mm and I estimate that on all three of these settings it is only cutting 0.5mm deep. I changed power settings again and dropped it until I stopped getting the flames (20%) but now that cut is even worse, looks more like an engraving.

So since this started happening I have stripped the machine down to realign the mirrors and clean it from head to toe. I then lubricated all the moving parts and sadly the problem persists and it is getting worse.

This leaves me with the idea that either the CO2 tube needs to be replaced or the air compressor is not working properly anymore (it sounds louder than it used to).

Any input would be greatly appreciated. This engraver is now my main source of income and this is making my job very difficult.

[buddydog]

Wide beam makes me think the lens is missing or broken, out of focus, upside down etc.?
edit: Also possibly "45* down mirror (top of head) alignment causing beam to hit edge of lens?

edit again: Just reread your post. Missing lens or cracked lens would allow more air out of head.

[Nolan Yang]

Hello, this is Nolan from Thunder Laser. you have had your current machine for almost 2 years and never change the laser tube? can you tell me how long the machine will work everyday?
if everything is fine, and the machine seems it is unable to cut straight through laminate sheet one day, I think the problem is your laser tube, it's time to replace it.
and how to replace it? you can visit our website. hope my suggestion is useful to you.
Have a nice day.
download - Thunderlaser

[II-DALTON-II]

Thanks for the replies guys. To clarify the useage of the machine, when i first got it it was just a hobby of mine, it would only see 4 - 5 hours of use each week. After 6 months I started getting requests however and at that point it became my business. From then until now it has been running about 20 hours per week so it has seen some fair use, in the area of 1700 - 1800 hours of use total.

I tried another test today, I placed masking tape on each mirror on the machine starting witht the one closest to the tube. I noticed that the burn hole that the laser made on the tape was larger and more distorted the further away each mirror was. So this means that the beam is getting wider as it travels correct? I also timed how long it took to mark the tape, the closest took approx 3 seconds and the furthest took approx 5 seconds before the laser marked it. The tape closest had an almost circular mark on it and the furthest resembled more like an island type shape. I cleaned the mirrors and tried this test 3 times, each time getting the exact same result.

[Nolan Yang]

Hello, this is Nolan from Thunder Laser, hope my suggestion can help you solve the problem.
below is a video about how to align the laser beam, even though your don't use our machine, I think the principle is the same.
https://www.youtube.com/watch?v=pw8Ro2vEEzY

and you also can contact with your supplier, ask them how to do. :cheers:

[buddydog]

Well that's a lot of hours on that tube so maybe it's the tube. You might swap it out as preventive maintenance (you should probably just get a whole spare machine if your running a business). You might swap mirrors around first to see if the problem changes somehow. You could have a strange shape burned into one. Also check the ends of the tube. The back end tube glue (by the high voltage connection) may be giving way and that mirror may be aiming off a little. The front one may have something burned onto it? It does sound like your troubleshooting tests are leading you in the correct direction. Good luck!

[buddydog]

That's a good video Nolan. I would suggest adding a line: "After confirming the beam is in the center of the mirror hole put that mirror back in before moving to the next step" or something like that although perhaps someone who couldn't figure that out has no business with their fingers anywhere near a laser machine:-) Yours is the first video I have seen specifying to check the lens center. Good job! Our little K40's really need all the alignment help they can get.

PS just reread your post "and you also can contact with your supplier, ask them how to do." I hope that was "tongue in cheek" ( a little American slang there). I'm not sure who the K40 suppliers are? I think they may all be manufactured on Mars! Nope when you buy a K40 it's "all yours". No one else is responsible. Maybe UPS or Fedex makes them since that's the only contact you will ever have :-)
BUT all that aside,I love mine!

[Nolan Yang]

Hello Buddydog, thank you for your suggestion, I will let our team team know this, if we have time, we will update the video.

and about the last problems, many manufacturers can't provide support to their customers, I really know that. but our Thunder Laser will try our best to solve the problems when our customers meet it, sometimes we can't solve it very soon and perfectly, and our customers' suggestion can help us improve the service. It is why our price is also expensive than others in China.
I don't know other manufacturers will how to do if their customers ask them for help. we just insist our principle.
Thank you again.

That's a good video Nolan. I would suggest adding a line: "After confirming the beam is in the center of the mirror hole put that mirror back in before moving to the next step" or something like that although perhaps someone who couldn't figure that out has no business with their fingers anywhere near a laser machine:-) Yours is the first video I have seen specifying to check the lens center. Good job! Our little K40's really need all the alignment help they can get.

PS just reread your post "and you also can contact with your supplier, ask them how to do." I hope that was "tongue in cheek" ( a little American slang there). I'm not sure who the K40 suppliers are? I think they may all be manufactured on Mars! Nope when you buy a K40 it's "all yours". No one else is responsible. Maybe UPS or Fedex makes them since that's the only contact you will ever have :-)
BUT all that aside,I love mine!

[rayscott]

With two years of service on the laser machine... I would recommend a new set of mirrors and possibly a new lens. The mirrors can start to distort the reflected beam ..due to heat stress and oxidation of the mirror surface. That is most likely what is causing the beam to diverge.

You should also check the laser tube's output coupler lens. Most people forget to ever clean it. The lens should be cleaned very delicately... but the result should be a lens that looks like orange cool-aide... in a clean and clear glass.

You should definitely check the laser beam alignment. That is the next ... top reason people start to lose laser power. I know of plenty of laser users that get 4+ years usage out of their laser tubes. It all depends on how you use and abuse the laser power settings.

As for if you really need to get a new laser tube.. You just don't know unless you test the laser output power with a calibrated laser power meter. The problem could actually be a weakened laser power supply, oxidized mirror, fogged lens, poor beam alignment,,,, etc.