Page 1 of 7 12345 ... LastLast
Results 1 to 10 of 70

Thread: 80 watt YAG - I broke it - Do'h

  1. #1
    Join Date
    Mar 2009
    Location
    Wesbury, Wilts,, England
    Posts
    125

    Unhappy 80 watt YAG - I broke it - Do'h

    After buying this rare, beautiful beast ---> ORIGINAL SALE THREAD HERE

    I am afraid to say I have managed to break it !

    I spent about 2 weeks solid reverse engineering the electronic internals and successfully managed to hotwire it for lasershow use.
    However, after about 10 minutes continuous use at a low power output whilst fitting/aligning some galvo's, the laser stopped emitting a beam.
    Please note, during this procedure, the Q switch was physically removed to prevent high power output and I was wearing suitable eye protection.

    Unusually, the pump source flash lamp was still lit and consuming the correct amount of current so I assumed it was an alignment issue as these lasers have a few extra mirrors in the main cavity.
    I checked the alignment best I could but could not get any green light at all.
    Next, I suspected the KTP crystal had died so removed the entire oven assembly out of the cavity expecting the 1064nm level to return but nothing !

    The only thing left to check was the YAG Rod itself which is deep in the lamp housing and probably the most fragile part of the laser.

    30 minutes later, I had it all in pieces but the fault may be very hard to see...lol





    For those who couldnt see... the YAG Rod is a bit cracked. !
    At least the lamp survived and looks brand new which is a bonus in my opinion !
    After a bit of head scratching, I have discovered the problem...

    These lasers have 2 water cooling circuits of which the internal is a De-ionised closed loop which only has temperature and pressure monitoring.
    I did incorporate these interlocks into the system hotwire mods but it would appear you can still get good pressure and temperature when the internal tiny reservoir (0.5 Litre) is low level.
    There is no way of visibly checking this without adding external pipes nor is there any electrical interlock -- poor design by the manufacturer !
    When low, the pump cavitates silently and pumps tiny air bubbles around the circuit which can lead to hot spots... BANG !!

    Needless to say, I shall incorporate my own level detection in the interlocks to prevent this happening again.

    Lucky for me, on ebay, I have managed to locate a replacement YAG rod for less than 120 USD.

    I have been asked to include some pictures with measurements as there is interest in how this tiny machine produces so much output !

    YAG ROD....


    LAMP....


    I was hoping to take this to the UKLEM but the parts wont be here on time...
    Last edited by Simon; 03-27-2014 at 04:50.
    Official "vag burner and big ass ION laser" fan club member

  2. #2
    Join Date
    Jan 2007
    Location
    Florida
    Posts
    4,382

    Default

    Wow, bummer man .. at least there's hope for a repair ..

  3. #3
    Join Date
    Oct 2010
    Location
    Wiltshire, UK
    Posts
    579

    Default

    Shit dude,

    Sad one, I did read somewhere that you are no longer coming to the Lem, there's still room to jump in with me, if you have nothing planed and there will be plenty of photons floating around.
    Squat that bug,

    One day I'll finish my build.
    https://www.facebook.com/Azteclasers?fref=ts

  4. #4
    Join Date
    Mar 2009
    Location
    Wesbury, Wilts,, England
    Posts
    125

    Default

    Hi Tony, I will let you know soon... thanks
    Official "vag burner and big ass ION laser" fan club member

  5. #5
    Join Date
    Oct 2010
    Location
    Wiltshire, UK
    Posts
    579

    Default

    Cool, be good if you can, its a great weekend..
    Squat that bug,

    One day I'll finish my build.
    https://www.facebook.com/Azteclasers?fref=ts

  6. #6
    Join Date
    Jan 2007
    Posts
    248

    Default

    ah, seems you will spend your another two weeks on it soon.
    http://www.viasho.com
    wzc@viasho.com
    Whatsapp: +8613911142669

  7. #7
    Join Date
    Nov 2007
    Location
    Bend Oregon USA
    Posts
    3,348

    Default

    I remember when you said this


    "Perhaps it is time for you to retire and leave the fun to us "not so old" people ...

    My plan is to get the 80 watter up and running for the UK LEM but I do not possess a power meter that big ! lol"


    Im sorry for your loss...but generally speaking...you should have heard the lamp electrodes "boiling" LOOOOOOONNNNGGGG time before breaking a rod...just saying'...

    I think I also said in that same thread...be sure you have lots of extra parts Good luck getting her back running..

    .OBTW...I hope the coatings on that $120.00 replacement rod are up to snuff

    just saying'

    I had to edit when thinking of spare parts.... I use to make my wife very nice dangling earrings with broken rods and nice stud earrings out of frapped KTP's
    Last edited by Laserman532; 03-28-2014 at 08:53.
    Pat B on alt.lasers


    Visit My Site

    laserman532 on ebay
    laserman532 on LPF

    Been there, done that, got the t-shirt & selling it in a garage sale.

  8. #8
    Join Date
    Jan 2007
    Location
    Florida
    Posts
    4,382

    Default

    Quote Originally Posted by Laserman532 View Post
    .. I use to make my wife very nice dangling earrings with broken rods and nice stud earrings out of frapped KTP's
    Damn .. that's some enginuity to keep the wifey happy and the happy hobby too

  9. #9
    Join Date
    Apr 2007
    Location
    Costa Rica
    Posts
    517

    Default

    When I bought my first old 20W "vag burner" in the '90's for $5000 it seemed like a real bargain. Now I'm seeing used 80W Greenlight "prostate burners" on eBay for around $2000 and replacement cavities with rod and lamp for a few hundred dollars. I used to pay over a grand for a replacement rod or ktp. These things are so friggin' dangerous with the high q-switched peak powers it's scary to think of inexperienced kids someday getting their hands on them. Hopefully the modifications are complicated enough to keep most people from trying it. Please be careful!
    ".... I use to make my wife very nice dangling earrings with broken rods and nice stud earrings out of frapped KTP's".. Pat you really have a way with the women! Just kidding - I have made gift earrings from tiny white ceramic and gold microchips.

  10. #10
    Join Date
    Feb 2011
    Location
    New Hampshire
    Posts
    3,513

    Default

    Simon,

    I agree that what you describe sounds like an engineering flaw. This unit for all its power is still a lamp driven YAG and so it seems that the perfectly adequate single closed loop DI cooling scheme used for the 40 watt'ers should work for this as well. Allowing you to eliminate the hook up to tap water would make this a lot more portable too. If really good water quality is needed then increasing the volume and more frequent flushes should help.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •