Top 2 reasons why your laser tube dies

Top 2 reasons why your laser tube dies

Most of us experience this sooner or later, but if you experience it really close to where your machine was delivered, here is the two top reasons why your laser tube died.

1: Overpowering the tube

While the tubes are called 40w, they cannot really handle 40w and has a effective output of about 30-35 watts depending on tube quality.
This mostly happens on the digital versions of the K40, where the milliamp. output isnt visible, only a percentage of the power.
Theese machines cannot handle 100%, they cannot handle 90%, you will overpower your tube at 90%, thus lowering the life span drastically.
If you have a digital version, i suggest installing a 30mA amp meter.
Keep your tube below 18mA at all times to be safe. You can go up to 20-25 but the gain is very little and you are strangling your tube for every second doing it.

2: Overheating the tube

This is pretty common, not having a clue about the water temperature in your tank and just running the machine.
The laser tube works the best at 15-20c water temp, anything above will degrade your tube.
If you run at 23c your tube will not die tomorrow, but you may lower the expected life time by a couple of weeks or month. So for some its ok to run at 23c as they know they need a tube change later on.
There is also a link between using wrong coolant to unexpected tube malfunctions.
Read more about that in the watercooling article.

But if you want to use your tube the most, keep temperature around 20c.
Whats happening when the temperature is too high is the regenerative gases has harder to regenerate inside the tube wich lowers the power output with time.
There is a deeper scientific explanation, but i keep it simple and understandable for now 😉

Quick info: Never go beyond 18mA and keep water att 20c or lower 🙂

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Comments (10)

  • Andrew Reply

    When you say the best temp is between 15 and 20 degrees , does that mean there is a loss of power when running the tube under 15 degrees? Was just wondering why this would be the case… cheers

    2018-08-28 at 17:03
    • HP Persson Reply

      Lower temp will introduce condensation on the tube (dew point), that might cause arcing in a bad situation. You do not gain anything with having the coolant colder than 15 either, just bigger risk of cracking the tube if you get a hot-spot or a flush of hotter water.

      2018-08-28 at 18:56
      • Andrew Reply

        Ok Thanks, I see your point. Will definitely keep that in mind.

        2018-08-29 at 06:59
  • Christian Forasté Reply

    Bonjour HP Persson

    Pour Un Bon fonctionnement Laser CO2 100w

    Quelle Température ?? °c

    Quelle Puissance Max ?? mA

    Merci De Votre réponse

    2019-02-06 at 16:18
    • HP Persson Reply

      It may be different between manufacturers, but above 20Celsius is not recommended. Some tubes, like RECI is made for 20-25C max. Max mA depends on the manufacturer, most 100W machines has 24KV output, max mA is then 28mA. If the output is 16KV, max output is 35-38mA – check with the seller for exact data.

      2019-02-06 at 16:48
      • Christian Forasté Reply

        Un GRAND MERCI
        pour la réponse
        HP Pression
        Super

        2019-02-12 at 10:22
  • Vitalie Reply

    What is the recommended % of laser power for quality of clean rubber engraving for making a personal seal with complicated logo without causing damage to the CO2 laser tube?

    2019-07-17 at 21:52
    • HP Persson Reply

      This is very different between machines, it depends on optical qualities, how good the machine is aligned and so on how much power you need. The best approach is to test it bit by bit, start at 20% and 150mm/s and see what you get – if its too light, lower the speed or increase power. But i would suggest installing a mA-meter, the %-meters are not very accurate, you are over-powering and damaging you tube already at 50-70%. A mA-meter will tell you the real power.

      2019-07-18 at 08:10
      • Vitalie Reply

        So, 1 px/mm and 1 pass is enough or the best is 2 px/mm and 3 passes at the 25% power and 200 mm/s for the Kehui KH-3020 Laser Engraver to engrave a 40mm personal rubber stamp?

        2019-07-18 at 08:24
        • HP Persson Reply

          Impossible to confirm or deny, even if you put two identical machines you have side-by-side, they will need different settings. You need to test it on the material you have. The machines are different and rubber stamp materials are different from different manufacturers, so the only way is to test it. I would go 1px/mm for everything.

          2019-07-18 at 08:27

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