50W CO2 laser. Cut power seem to continue declining after a job with no cooling

I have a generic Ruida laser. It has worked very consistently, but a few weeks back, my water cooling ‘bucket’ got a small leak I didn’t detect. After sending a job and it not doing any of the cuts, I realized the water had completely drained and the laser ran the job with no cooling. I replaced the container and it seemed to work fine. However, after a few more jobs, I am noticing the cut power is much less than pre-incident. I am guessing the laser was damaged. I have had to drastically reduce cut speed to continue cutting wood patterns. What I used to cut at 15mm/s, I now can barely cut at 5mm/s. I have confirmed the laser is aligned and the mirrors and lens are clean. Any other thoughts why the power might drop? Would losing the cooling do this to a laser? Appreciate any advice.

Is this a diy project?

No ‘water protect’? This is why there’s an input for it to the Ruida … lower cost than a new tube…

Check the tubes beam at m1. It should be TEM0 resonance. If not, new tube time…


Temperature does damage tubes, the hotter they get the less power they output.

This is one of the reasons my laser has an aquarium water heater in line with the cooling loop. I bring the whole system up to temperature (20C) before I start any engraving job, the consistent temp means I don’t start the etch super hot then have the power drop off as the tube gets to temperature. Sorry about your tube, but its probably toast.

It is what seems to make sense. Do you know if there is any way I can confirm? Not really sure how to know, but it definitely does seem to have less power than in the past. Appreciate the response.

I have no idea how to do what you just described, but I will do some searching and see if I can figure it out.

Is this a diy? Does it not have a water protection circuit?

It’s like aligning a mirror. Put a ‘target’ in/on mirror 1 (m1) and pulse the laser enough to make a brown mark. M1 is the first mirror the beam strikes.

The ‘burn’ should look like this:


Less power the better to see…

Good luck


I can do a pulse and get a similar mark, I do get etching and cutting, but the power is vastly reduced from traditional operation

Is this a diy?

Can you post a photo of it.