Powerdrop during cutting job

Hi everyone,

During the last 3 months me and my friends are trying to solve a really big issue.
We own a 100watt co2 laser from omtech.
We observed this behaviour when we were trying to cut MDF. Everythings fine when starting the job, the material gets cut but then the mA starts to drop and we are not able to cut it anymore. Let’s say we start at 20mA, after 15 minutes we are down to something like 14 mA.
We have changed the tube 2 time and the power supply once as suggested from the manufacturer.
Nothing worked…
Do you have any idea on what it could be? Anything we can measure? Some settings that just reduce power over time?

Thanks a lot in advance and hopefully we will be able to enjoy it more once this is fixed.

Have you checked tube cooling?

I bet is that… if the tube is not let’s say between 17-23° the power is affected

We monitored the water for about 30 minutes and the temperature was all the time between 16-20°. We use a cw5200 chiller

Start at the beginning…

Check the tube resonance by a target before m1. Don’t punch a hole through it, just a light burn so you can see the beam power areas.

Sorry can’t post the photo.

Ensure it’s running in TEM0 state.


All 3 tubes produce a good dot, full clean circle