ML Lister Magneto questions

Discussion in 'Help Wanted' started by campingstoveman, Feb 1, 2009.

  1. campingstoveman

    campingstoveman Active Member

    Gentlemen,

    What does the team think, I have stripped down a ML Lister MK1-4 mag today as it was seized, the rotor and body had a coating of rust stopping the rotor from turning.
    I was unable to remove a hex head screw with a point at the thread end, this screw is at the sprocket end, because the head sheared off so need to drill it out. Does anybody know what the thread is and what does the bolt do anyway.
    Can I use general purpose grease for the bearings which I have cleaned.
    I also have to make a Carbon brush pickup body as the old one disintigrated, are there drawings of this part.


    I await your thoughts.

    Martin P
     
  2. highrange

    highrange Member

    Can't help regarding the thread size, but I suspect the pointy screw is a safety device used by some mag manufacturers to earth the spark ( from slipring to pointy screw) if the HT lead is disconnected... could avoid damage to the HT winding..... at least this was the case in some motorcycle magnetos.
     
  3. ArthurG

    ArthurG New Member

    Martin,

    can you post a picture of the mag, I think I've got a rough one if you want some bits.

    Regards,
    Arthur G
     
  4. boblester

    boblester Member

    Martin...
    Martin i suspect you are refering to the saftey gap screw, as pointed out should the lead fall off the plug whilst running the screw gives a set air gap to enable a spark to discharge any dangerous high voltage and stop any damge to the windings, also if you dont remove it you will have a chunk missing from the slipring insualtor when the armature comes out :( .

    Rgds
    bob
     
  5. petternut

    petternut Administrator

    I'm with Bob. Please also bear in mind that the slip ring insulator is an early and fragile form of thermo-plastic. If you have to remove it (unlikely) a hot air gun will make it pliable enough to remove.

    regards
    Roland
     
  6. campingstoveman

    campingstoveman Active Member

    Gentlemen,

    The head sheared off of the Gap screw so pointy bit still in place and yes it did remove lump from insulator ring, fortunately it broke in one piece so Loctited it back and you can nearly not see the join. Will drill out broken bit but does anybody know the thread so I can drill the correct size hole. Forgot to ask Bob what connections do I use to determine state of coil to make sure no faults and I assume general purpose LM grease for bearings.
    Thanks so far for info.

    Martin P
     
  7. boblester

    boblester Member

    Martin...
    resistance check from the comm to the body of the armature, LM grease is fine .

    rgds
    bob
     
  8. campingstoveman

    campingstoveman Active Member

    Bob,

    Ta, now all I need is thread size.

    Martin P
     
  9. Or another magneto, but this time a good one!!! :lol: :lol:

    Regards

    Andy
     
  10. campingstoveman

    campingstoveman Active Member

    Andy,

    Apart from a line of rust between the stator and the magnet its actually in good order and I dont expect problems when reassembled.

    Martin P
     
  11. TangyeDan

    TangyeDan Active Member

    Has your ' key stopped working?

    :lol:
    Dan
     
  12. campingstoveman

    campingstoveman Active Member

    Dan,

    ??????????????????
     
  13. TangyeDan

    TangyeDan Active Member

    Nope - wrong key again. You need to use the ' key, below the @ between ; and # in both "its" and "dont" (sic) in your original post.

    :lol:

    Dan
     
  14. campingstoveman

    campingstoveman Active Member

    Dan,

    You are starting to get a tad annoying, the sooner you get a job and get home to knackered to spot these things' the better. :lol:

    Martin P
     
  15. miley_bob

    miley_bob Member

    What do you mean starting to get annoying? He's been that way for years. :lol: :lol:
     
  16. ploughman

    ploughman New Member

    Hi,
    as you have drilled out the old screw, make up the new one in any handy thread and tap mag to suit.
    Regards,
    Harry
     
  17. lambe

    lambe Member

    Martin, re the thread of the screw (returning to the point ) :roll: checking one of mine is 3/32 or1/8 whit
     
  18. RichardJ

    RichardJ New Member

    It's close to, but not quite 38 tpi, not Whit or BSF.
    It could be 4BA

    Cheers
    Richard
     
  19. campingstoveman

    campingstoveman Active Member

    Gentlemen,

    The thread is 8-36UNF. Now all I need is a tap :lol:


    Martin P
     
  20. TangyeDan

    TangyeDan Active Member

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