Page 1 of 2 12 LastLast
Results 1 to 10 of 20

Thread: HELP ... Old Sparky is sick and needs diagnosis and treatment

  1. #1
    Join Date
    Aug 2016
    Location
    Appalachian Ohio
    Posts
    858

    Default HELP ... Old Sparky is sick and needs diagnosis and treatment

    Some of you might remember Old Sparky, the 1930's (or earlier) motor that runs the Battle Shaper. Well, old Sparky has lost the get up and go.

    Sparky was running fine last fall, and then I didn't use the shop much when the shop temperatures fell below freezing. Then the long spring happened, when the temperatures are cold at night and the warm humid air caresses everything with it's damp dew generating breath. SWMBO finally listened to me complain about that one time to many and told me to pay to have the shop insulated and sheathed and new lights and stuff... WHEEE...

    But now old Sparky won't turn over. It turns over easily by hand. There is also a HUMM when I turn on the power (very briefly). I even tried spinning it once while the humming was happening. Nothing. I'm so sad.

    So, how do I diagnose one of these motors? Assume I have DMM and basic electronic stuff. I just don't know much about motors.


    Old Sparky before cleanup and repainting:


    Old Sparky nameplate before cleanup:


    Old Sparky after cleanup and repainting:
    Last edited by Dan_the_Chemist; 09-12-2019 at 01:15 AM.

  2. #2
    Join Date
    Jul 2017
    Location
    Buffalo NY USA
    Posts
    534

    Default

    Unfortunately I can't help much but I just wanted to say, Damn that's a beautiful motor. If it just sits there and hums, I would think that whatever starting mechanism it has, is having a problem. I would start by cleaning out all corrosion, everywhere.

  3. #3
    Join Date
    Jan 2013
    Location
    Michigan
    Posts
    1,961

    Default

    I'm not much of a motor guy, but I'd guess checking resistance, to identify compromised insulation and other shorts, would be on the, uh, short list.

    Somewhat on topic, how do you protect an open frame machine motor like that, while in less than ideal storage conditions? Outside of a machine, I suppose you should crate it in wood. But in a machine? I suppose wrapping it in a blanket would help quite a bit, for cases where it is not in use. Anything else?

  4. #4
    Join Date
    Jul 2005
    Posts
    145

    Default

    Check and clean brushes and commutator. Check voltage across line while trying to start.

  5. #5
    Join Date
    Jun 2017
    Location
    Central Arkansas
    Posts
    2

    Default

    Mud dauber maybe?
    I loathe them.

    Seedtick

  6. #6
    Join Date
    Feb 2012
    Location
    Metcalfe, Ontario, Canada
    Posts
    1,376

    Default

    It was never clear to me in the previous thread on Old Sparky whether or not, in his case, "repulsion induction" meant "repulsion start, induction run", which is the case with the motor on my 1940's era Delta Unisaw.

    If so, you may find there are copper "fingers" around the commutator which short out the commutator when the motor has come up to speed. At least I think that's what they do, it's been a while since I last worked on the motor. The fingers have somewhat of an L shape, and there is a garter spring around them which IIRC holds them away from the commutator until centrifugal force acting on the other leg of the L overcomes the spring and pushes the fingers into contact with the com. ( Yes, I myself am entirely unable to visualize this at this point in time.)

    Anyhow, the motor buzzed and refused to start when the temp was -20C or so, and then when it wasn't, so attention was required. The spring was stretched, possibly from overheating. I tried a couple of garter springs from oil seals, found one that worked , but it gave up after a while. Tried a few likely sizes of O-rings, found one that worked, and the motor has been starting and running fine for years now, other than needing the brushes replaced.

    Of course, if Old Sparky is not a repulsion start motor, this is just useless verbiage. And if he is, he may use an entirely different system, so ditto.

  7. #7
    Join Date
    Apr 2010
    Location
    Canada
    Posts
    2,799

    Default

    A bit of old 'technology' Repulsion induction, one thing to check is if the comm holders have moved, as the brush holder set is used for a rotated setting for either FWD or REV.
    Old, but pretty reliable, may be just needs a little TLC in the form of a strip down and clean?.
    Max.

  8. #8
    Join Date
    Aug 2010
    Location
    Victoria BC
    Posts
    896

    Default

    I once had one like this that called itself a "repulsion induction". You could rotate the brush holder around the axis to alter the relationship of the brushes to the field windings. It made a huge difference in speed, maybe direction - don't recall after all these years. I expect there was a position in which it would not turn at all, but just hum. (But maybe it's just humming like many of us do, because it doesn't know the words..)
    "A machinist's (WHAP!) best friend (WHAP! WHAP!) is his hammer. (WHAP!)" - Fred Tanner, foreman, Lunenburg Foundry and Engineering machine shop, circa 1979

  9. #9
    Join Date
    Aug 2016
    Location
    Appalachian Ohio
    Posts
    858

    Default

    Quote Originally Posted by Seedtick View Post
    Mud dauber maybe?
    I loathe them.

    Seedtick
    *BING BING BING*
    Give that man a seeegar !!!

    I traced the 220 V from the wall to Old Sparky, through the antique lever switch with real FUSES, the 1950s (?) contactor, and the off/on switch and I found volts all along the way (and didn't kill myself!). While looking at the business end of the motor, in amongst the brushes and stuff, I noticed a bit of mud. Carefull prodding with a bent wire (and the power off at the breakers), revealed that some dauber had built a nest in the midst of all the close-together parts. Some time with the wire, a lot of curse words, some time with a damp cloth, some iso-propanol, a little time to dry, and

    Old Sparky is ALIVE !

    Thanks to everybody who answered. It gave me the confidence to start digging into this priceless artifact from last century. The Battle Shaper makes chips again !!!

    Last edited by Dan_the_Chemist; 09-12-2019 at 09:02 PM.

  10. #10
    Join Date
    Jul 2017
    Location
    Buffalo NY USA
    Posts
    534

    Default

    Glad you found it, and thanks for getting back to us! Where exactly was it, was it jamming the brushes or something?

Posting Permissions

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