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Thread: Picked up a couple more CO2s, one was a bit toasty

  1. #1
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    Default Picked up a couple more CO2s, one was a bit toasty

    I picked up a couple more CO2s, a Rofin SC x30 (9.27um @225w) and a Coherent E150 (150W at 10.6um). The E150 works, the rofin... well, not so much. The 48v, 150A power was roasted. Best I can tell is the output inductor core cracked which ended up shorting out the output and frying itself. Luckily there was a second inductor of the same size in the power supply and I was able to measure it and determine the permeability of the core and wind a new one. After replacing a bunch of other components that were damaged from the heat and smoke the power supply works again. When this happened I found it also killed the dc/dc converters in the head and the RF power supply so I got to repair those as well. But it finally works after 2 months of working on it.

    Burning some wood here, measured output at 225w like its supposed to be, the laser has a much higher peak power at lower rep rates.

    Pics of the internals and repairs here: https://flic.kr/s/aHsmVebSR9

    Thread over on HSM where I logged the repair: https://bbs.homeshopmachinist.net/fo...little-crunchy

  2. #2
    mixedgas's Avatar
    mixedgas is offline Creaky Old Award Winning Bastard Technologist
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    I'd call that an heroic save. Nice job, from flamed trash to flame thrower… Nice.

    Steve
    Qui habet Christos, habet Vitam!
    I should have rented the space under my name for advertising.
    When I still could have...

  3. #3
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    Im still a bit shocked I got it working. Luckily a few tips to look for why it fried and just got very lucky the damage to the head and rf power supply was limited to what it was.

  4. #4
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    I have 2 SC x30 also..
    Nominal power i think is 300w not 225w.
    Mine DC PSU and RF PSU are separate not combined.
    Do you have some info for gas mixture percentage for refilling ?

  5. #5
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    225w is at 9.27um which has lower gain than 10.6um so less power.

    DC power supply and RF power supply are separate modules in a single box.

    Nothing on the gas mix, Photovac says they can refill them.

  6. #6
    Join Date
    Feb 2019
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    photovac is in US so you must pay customs and a lot of shipping-return costs + repair cost.
    To get 3 cylinders of 99.999% pure He/N2/CO2 + 2 stage vacuum pump(used) costs less than send it to photovac.
    So in house refill is reasonable option

  7. #7
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    Three bottles of gas, mass flow controllers, barotrons, and you are really going to want to pump down with a turbo pump to keep oil vapor out and get a better starting vacuum. Plus the catalyst may need to be replaced and optics should be inspected. There also may be other trace gasses too. You could pump down with a mass spec connected and see what's in there.

    Found this on the web

    "Rofin-Sinar use 6 component mixture Xe/O2/CO2/CO/N2/He for their multikilowatt DC series lasers, typical composition is 3/3/6/4/19/65.
    Mixture H2/Xe/CO2/N2/He = 1/5/18/18/58 was also reported in literature.
    Optimal pressure is generally around 70-100 mbar."


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