Results 1 to 17 of 17
  1. #1
    Knguyen is offline Cast Iron
    Join Date
    Jun 2003
    Location
    Bergen, NJ.
    Posts
    444

    Default Doall blade welder stops working

    Dear gentlemen,
    My doall band saw blade welder (DBW 1) was doing fine until today when I tried to weld a 3/4 " blade for my Horizontal band saw. Mounted the blade on the holders and pushed down the levers and nothing happened. I wonder if there is a fuse that was blown or it was a commonly encountered issue that can be resolved with simple maneuvers. Any input would be greatly appreciated . Thanks in advance.
    Khanh

  2. #2
    gary350 is offline Hot Rolled
    Join Date
    Aug 2008
    Location
    Murfreesboro, TN. USA
    Posts
    640

    Default

    DoAll guarantees just about every thing they sell. Get a replacement. The one we had at work quit working because the ground had a bad connection. I cleaned it and it worked fine.
    Last edited by gary350; 01-01-2013 at 03:35 PM.

  3. #3
    HuFlungDung is online now Diamond
    Join Date
    Jan 2005
    Location
    Canada
    Posts
    6,521

    Default

    I don't know how it is built, but there is a possibility that there could be a bad microswitch inside, so when you push the weld lever, its simply not closing the main relay anymore?

  4. #4
    GregSY is offline Diamond
    Join Date
    Jan 2005
    Location
    Houston
    Posts
    4,247

    Default

    Yes, I would recommend you call DoAll and tell them you have a 40 year old device that has stopped working. They will be sure to just send you a new one.

  5. #5
    Knguyen is offline Cast Iron
    Join Date
    Jun 2003
    Location
    Bergen, NJ.
    Posts
    444

    Default

    Thanks, I did open the panel and looked behind the unit . Not sure if it has a fuse but a micro switch is possible. Nothing on no welding on trouble shoot section of doall. The thing is well built . Wonder if you can check for presence of electric current using a meter.

  6. #6
    metalmagpie is online now Hot Rolled
    Join Date
    May 2006
    Location
    Seattle
    Posts
    955

    Default

    With the box open and the grinder powered up, get out your voltmeter and start tracing power from where it comes to the box all the way to the transformer. Probably you didn't blow the transformer. If a fuse blew then do NOT just jump it and try it again, that's how you really F something up.

    When it goes from having power to no power you have isolated the problem.

    Hopefully it is something simple like a switch's contacts needing cleaning.

    metalmagpie

  7. #7
    Mike72's Avatar
    Mike72 is offline Hot Rolled
    Join Date
    Aug 2004
    Location
    Illinois USA
    Posts
    585

    Default

    When was the last time you lubricated the moving blade mechanism? I've had mine stop working after 50 years and some oil was all it needed.

  8. #8
    gregoryd's Avatar
    gregoryd is offline Cast Iron
    Join Date
    Jun 2007
    Location
    Mass
    Posts
    377

    Default

    Quote Originally Posted by Mike72 View Post
    When was the last time you lubricated the moving blade mechanism? I've had mine stop working after 50 years and some oil was all it needed.
    Mine also needed similar attention. It is a spring balanced mechanism that if parts get sluggish due to dried oil the slides hang up and do not make contact.

  9. #9
    surplusjohn is offline Diamond
    Join Date
    Apr 2002
    Location
    Syracuse, NY USA
    Posts
    9,167

    Default

    i have worked on many of these. I have seen WWII era welders with broken wires, but most of the time they just need a really good cleaning and TLC. the voltage is very low so any dirt will stop the current. Look at the face where they clamp the blade, it should be flat and clean, of not dress it up on a belt sander. this often is all that is needed to make it work like new.

  10. #10
    tnmgcarbide's Avatar
    tnmgcarbide is offline Titanium
    Join Date
    Jul 2004
    Location
    N. GA- 33.992N , -83.72W usa
    Posts
    2,455

    Default

    i had an old stryco that acted the same way . oxidation/corrosion was the problem - i polished EVERYTHING that had electrical contact and it worked like new .

  11. #11
    johnoder's Avatar
    johnoder is online now Diamond
    Join Date
    Jul 2004
    Location
    Houston, TX USA
    Posts
    21,115

    Default

    The JAWS also have to be scraped clean. Ever look at the manual?

  12. #12
    Knguyen is offline Cast Iron
    Join Date
    Jun 2003
    Location
    Bergen, NJ.
    Posts
    444

    Default

    Thanks gentlemen, I'll give it a good cleaning and see what happens

  13. #13
    Join Date
    Dec 2003
    Location
    suburbs of Ann Arbor, MI, USA
    Posts
    12,260

    Default

    Its already been said but its a resistance welder. Good electrical connections are a must. Even if the outside of a bolted connection looks good it can have pitting and arcing underneath. If you had thermal imaging you may be able to find the problem if its barely welding as a bad connection would have enough differential to be detected.

    A bad connection can sometimes be improved in a pinch with some copper based anti-seize.

  14. #14
    Knguyen is offline Cast Iron
    Join Date
    Jun 2003
    Location
    Bergen, NJ.
    Posts
    444

    Default

    After a thorough cleaning, I checked also voltage across the transformer secondary output and there was none. There was voltage input from the primary. Conclusion: the transformer is fried. I am thinking of replacing the transformer or even rewiring it. Has any one any experience doing this? Thank

  15. #15
    surplusjohn is offline Diamond
    Join Date
    Apr 2002
    Location
    Syracuse, NY USA
    Posts
    9,167

    Default

    does it smell burnt? if not, then maybe you just have a broken wire.

  16. #16
    Knguyen is offline Cast Iron
    Join Date
    Jun 2003
    Location
    Bergen, NJ.
    Posts
    444

    Default

    No, not at all. Would you suggest rewiring to replace the broken wire? which I think the way to go but my electrical skill is quite limited. Perhaps getting a replacement. The one from Doall quoted $1700!!!

  17. #17
    surplusjohn is offline Diamond
    Join Date
    Apr 2002
    Location
    Syracuse, NY USA
    Posts
    9,167

    Default

    I was going to guess $1700.oo but I did not want to sound negative, You might have luck taking it to a motor re-wind shop. I never had a transformer re-wound. The old wires get pretty brittle so if you are lucky maybe one broke out side the coil. clean it up and look at it carefully. DoAll 's re-placement parts are crazy expensive. About 20 years ago I got a quote on a ML table trunion , $1700.00. for a 5 pound iron casting. I had one made for about $250.00.

Bookmarks

Posting Permissions

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