Ideal Water Temperature to Maintain For a Water Cooled Laser Tube?

[Doug Fisher]

Does anyone know this temperature number? I can't find one in my poorly written manual.

Thanks,
Doug

[John Noell]

Dave Sheldrake (who is extremely knowledgeable on the subject) has said, "Beam profiles change in DC tubes when they get hot, the window to operate a DC tube efficiently with a stable beam is only +/- 1.2 - 2 degrees. On a narrow body tube it should be kept between 20 to 24 degree's (on a wide body, 17 - 21 degree's). Hit 24 on a narrow body and you will start losing tube life exponentially as it goes above that. Temperature stability is absolutely essential in DC tubes."

[Jeff Body]

What's the difference between narrow and wide body?

[Doug Fisher]

x2 on that question!

Thanks.

[Dave Sheldrake]

Narrow = 50mm , 55mm and 60mm diameter tubes,
Widebody = 80mm and 90mm diameter tubes,

The single most important word in DC laser cooling is "stability" keep the temperature nice and stable (+/- 1 degree if possible) and you will get premium life and beam profiles from DC glass tubes. All my chillers are set 17 - 19 degrees C (all widebody tubes)

Low temperature can have benefits but at the cost of other issues like condensation so it pays to stay above 16 degrees if you don't want to run your chiller to an early death.

Avoid thermal shocking by turning on a chiller after the machine is running. Turn on and leave a couple of minutes to get the entire water reservoir volume to a stable even temperature before firing up the laser to work.

Mine run 16 to 18 hour days and an EFR ZX/ZS tube will on average last 5 years (I just changed out a ZX1850 that was Jan 2012 manufacture date when it got down to 130 watts output) the CL1200 60 watt is usually good for 3 to 4 years if you cut a lot but engraving due to the higher stresses involved (lots of on and off cycles per day) will take quite a bit of time off of that.

[Doug Fisher]

Thanks for the great information.