Cutting is charring on leather when it has never done so

We’ve been running our co2 60w for 3 years and put it through thousands of hours of work, plus our other lasers. So our knowledge is pretty deep on these lasers after doing probably 5000 to 7000 of laser work (only throw that out there for context). But we’ve had an issue lately where our 60w laser when cutting leather is cutting too hot. I checked our water levels and water pressure going through the laser and all is good. I did test different laser settings but it’s still cutting way hotter than normal, yet focus is good and fill is still good. Absolutely puzzled on this one. Anyone experience this?

Does the mA reading from the ammeter match the setting from LightBurn/the machine?
A “normal” power test will perhaps shed some light on the problem. If the tube is not on its way out, after all the hours you mention and you cannot control your power settings, it indicates a problem with the high-voltage power supply.

The either the laser tube is failing after pretty much its expected lifetime or the HV power supply is failing because that’s apparently what they do. In this case, I’d bet on a tube failure.

Although the focus may seem fine, the beam may no longer be a round spot. To check this, measure the beam shape at the entry to the first mirror; the discussion in this thread gives some details:

If the beam shape looks good, then suspicion falls on the power supply.

Power supplies tend to be cheaper and easier to replace than the tube, so that may be a reasonable starting point. Bonus: if the new supply doesn’t solve the problem, you know what’s next and you have a spare supply on the shelf.

Thank you Ed and bernd for your comments.
The machine power meter readout is still showing levels consistent with the settings, typically 24mA at 60%.

I got the new 130w machine installed just before the weekend to help me catch up on orders and I’d say the cut quality on day 1 was better than I’ve ever achieved with problem machine. I’ve also spent a few hours with Russ Sadler’s videos which are excellent, and so I’ll go through the alignment and recheck all my settings one more time before I contact the vendor.

I’m a believer in having critical replacement parts on the shelf - a tube would be on that list but my understanding is that it will deteriorate even when idle ?

Perhaps somewhat less rapidly, but tubes do go bad on the shelf.

Given your fleet and heavy usage, replacing tubes based on usage, rather than waiting for them to go bad and wreck production while you figure out the problem, might be sensible. If you have a couple of similar machines, keeping one common tube as a spare for maybe half a year seems sensible.

Thanks much! I’ll check the mA reading as that could be it. Sounds like it might not be a bad idea to replace the power supply and the tube anyway!

Thanks much! I’ll order both a new tube and power supply as we’ve got our fair bit of work out of this one anyway. Appreciate it!

I didn’t notice this wasn’t my topic when I posted earlier. My apologies.

All good, hope it helped!

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