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Unsticking Armature Shaft (Sumter No. 12)

forney00c

Registered
I finally got the last piece of the puzzle for my 1916 Fairbanks headless, the magneto. It's all there except for a good base and brass band, but it is stuck. I've been putting a little bit of PB Blaster on the ends of the shaft, hoping it will creep in and help loosen it. Does anyone have some other tips to get the shaft unstuck?
 

Nick

Registered
Age
38
Last Subscription Date
04/18/2014
Could be rust between the armature and poles which is more likely to be the cause of your troubles rather than a steel shaft in bronze bushings. I'd pull the whole thing down and do a proper job of cleaning things up.
 

Tom Marshall Jr.

Subscriber
Age
76
Last Subscription Date
12/29/2019
I have seen tar oze out of the armature when stored where hot and get in between . warm it up with a hair dryer see if it will turn If so take it apart and clean it up .
 

mmcdonald

Sponsor
Last Subscription Date
04/13/2017
If you're afraid you're going to damage the magnets you could remove them but I don't know how much that will have to do with getting the armature free. It could be stuck in the bushings but more likely rust or tar from the coil has stuck it. You'll probably need to remove the end plates to get to the problem or at least where you can see it. If it's rust, rubbing alcohol/WD40/(trans fluid/ATF) or whatever your favorite is and gentle tapping may free you up. If it's tar from the coil, carburetor cleaner or some other solvent will have to be applied. There are things better than WD40 in many situations but in my own experience it's a great tool for a case like this. It will help with rust somewhat and it also softens tar type substances. If tar is the problem, don't worry about not getting the solvent on the coil itself as it's more than likely shot anyway.
 

newway1978

Registered
Place the mag in a pot of water and boil remove and try to turn it on the gear have tried it a few times worked good
 

forney00c

Registered
Okay, so hopefully in the next couple days, I can try to pull at least one of the side covers off and see what I'm working with. If the tar melted out of the armature, I'm guessing I'll probably have to send the armature in to have it rewound? Hoping it just a little rusty and the armature coil isn't shot.
 

Tom Marshall Jr.

Subscriber
Age
76
Last Subscription Date
12/29/2019
The one I had leaked a minimal amount and worked quite well after cleaning , think positive .
 

forney00c

Registered
I keep spraying this mag down with PB Blaster, but so far I can only get one screw loose on the front cover. The gear is also stuck on the shaft and I've tried tapping the edges of it to persuade it to move a little, but no such luck yet. Any tricks to getting these very stubborn screws out? I don't think I would want to try any form of heat and risk doing more harm to the mag than good.
 

forney00c

Registered
A little bit of progress has been made, as I finally got the drive gear off of the shaft. I'm still soaking everything down with PB Blaster whenever I walk by, hoping I can get a little to creep into the threads and loosen up some of these stubborn screws on the side plates. I guess the best route right now is PB Blaster and patience.
 

Tracy T

Subscriber
Last Subscription Date
07/16/2019
you may try tapping the head of those screws lightly with a small hammer to break the rust loose, not too hard though!
 

forney00c

Registered
Tracy, I do occasionally put my screwdriver in the slot and then tap on the handle of the screwdriver with my small ball peen. It does seem to help a little to get things moving once in a while.

Doug, I haven't taken the magnets off yet, but that will be next after I get the side cover screws out. Having those magnets in place gives me something to hold for a little extra leverage while working on getting these screws loose.
 
Last edited:

Tim B

Subscriber
Last Subscription Date
05/06/2019
I had an Edison on a Gravely D that locked up because the "tar stuff" melted off the windings around the armature. The mag is located right below the carburetor. Ive had 3 of these tractors that I thought the engines were locked up, but fortunately was only the mags.
 

cobbadog

Registered
Hi Tim, is it possible to put like a heat shield under the carby but above the magneto to stop that happening again?
 

Tracy T

Subscriber
Last Subscription Date
07/16/2019
Hi Tim, is it possible to put like a heat shield under the carby but above the magneto to stop that happening again?
also make me wonder if carb overfilled at some point if that didnt cause the "tar" to dissolve and get into places it shouldnt and then set back up like cement and cause the seziure?
 

Tracy T

Subscriber
Last Subscription Date
07/16/2019
Paul Spence brings up a very good point, my neighbor and i was working on a piece in the lathe. couldnt chuck it on the inside or the outside so we made a fixture to hold it .002" bigger than the inside of the piece we were working on. when it came time to remove the fixture it would not budge! we ended up machining the fixture to get it apart! so if you have any rust behind the magnets even enough to move them a few thou you basically dealing with a pressed fit now!
 
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