I am beginning to think you need to tune your laser PSU (as if the PSU is set too low). To do this, you need to know the highest mA draw specification for the laser tube longevity. A guess for an 80w tube may be somewhere in the upper 26 - 28 mA range (but you need to check to be sure).
With this number in mind and with a mA meter on the machine (if you don’t already have an ammeter installled on the machine, they’re a pretty easy retro fit down stream of the laser tube) you can properly tune the laser PSU through the adjustment trim pot.
The cut off floor of your tube should be <= 10%. But this isn’t going to change your results of what you say is over burn (you’re just moving the scale down). You fix that over burn with faster movement, application tape, longer throw lens, air assist, de-focus technique, etc.
Ok so I purchased the tool suggested. Just a note although slightly irrelevant, but my new tube is 100 watts. Also on the power supply there is a screw with a hole, and you’re saying that this can be used to calibrate the PSU. One more question, how can you tell the max rating for Ma that a tube can withstand?
Yes, that screw you pictured looks to be the trim pot. Turning it should adjust the output (in response to the PWM signal sent to the laser PSU) up or down. To determine the suggested upper mA limit on the laser tube, you’d need find that through either the tube manufacturer or vendor. or example, a Reci W2 Series 90 - 100w laser tube is spec’d for 29mA working current (so if you had a Reci W2, you’d calibrate the PSU in this case so that when you send 100% power, the mA meter registered 29mA).
I’m not sure what you’re asking. Are you asking if it is possible by way of measuring the tube’s dimensions to determine the laser tube maximum suggested current allowance specified by the tube manufacturer? Do you not have a label on the tube indicating its maker?
