Wood Works Pinion Replacement

Harv

NAWCC Brass Member
May 12, 2010
14
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3
Benton, PA
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Good morning - I am relatively new to clock repair; a few years ago I attended the week-long hobbyist course at the NAWCC school. Since then, I have supplemented with weekend courses, including the wood works clock class. I truly enjoy working on wood works clocks, and have worked on a half dozen or so with great success. I have a 30-hr Terry type movement ready to re-assemble, and ran into a small glitch that perhaps someone will have a repair tip to proceed.

I need to replace two pivots - one on the Time 2 wheel and one on the govenor. It appears someone replaced the T2 pinion somewhere along the way, but it is badly grooved - too grooved to polish out. The govenor's pivot is badly bend. The problem is that I do not have an exact replacement size in my pivot wire assortment packets sold by the various supply houses. It appears I will need to use a smaller diameter pivot, but I am not sure how to firmly secure the replacement in the arbors for a solid fit. This should be an easy repair, but I am just not sure on the best approach. I will appreciate any thoughts from fellow repairs. Thanks. Harv.
 
Last edited:

John Teeter

NAWCC Fellow
NAWCC Member
Golden Circle
Jan 31, 2001
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Hi Harv,
There are couple of things that you may do. First, you do not need to replace the pivots with pivot wire. The originals are just soft wire. They are just driven in to end of the shaft. You might try pulling them out and reversing them. You may have to file the end to smooth it. If that doesn't work you can just replace them with soft steel wire and then the polish the actual pivot portion. The original wire diameter is usually 0.065 and a few thousands either way should not be an issue as these pivots run with much more clearance than in a brass movement. This is done to account for the out of roundness of the wheels. Because the original pivots are realatively soft, they can usually be straightened but becareful not to split the shaft.
John
 

Harv

NAWCC Brass Member
May 12, 2010
14
1
3
Benton, PA
Country
Region
Hi John - Thanks. I am a fan of this site and almost did not post this question as it seems rather trivial.

One of the pivots in question was previously replaced with a piece of 0.085 piece of wire that has grooves down one side. It also shakes right out as the pivot hole opening on the end of the arbor is 0.092 mm. I have a piece of wire 0.079 that I thought I could use if there was way to be sure it would stay secure after tapping in the arbor. I wasn't sure if something could be used to secure, such as hide glue or some other type of reversable fastener, to fill in the opening or use when tapping into the arbor. Plus, the 0.079 just fits in the pivot hole opening in the top plate - wire with a greater diameter will require opening the pivot hole in the plate. Again, I was just hoping to find an acceptable way to proceed. Thanks again. Hary
 

John Teeter

NAWCC Fellow
NAWCC Member
Golden Circle
Jan 31, 2001
56
1
0
Harv,

Youi might try making a stepped pivot wire, one with end the size you need to fit into the wood shaft, .085 Dia., and the other .065 Dia. for the pivot end. Its not too hard to turn soft wire.
John
 

Jim DuBois

Gibbs Literary Award
NAWCC Member
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Jun 14, 2008
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Magnolia, TX
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I have used coat hanger material directly from the cleaners for a long time. The wire originally used for pivots is dead soft, no better no worse than coat hangers. Shirt hanger wire diameter is smaller than that used for coats and the like, so a small size and a larger size is readily available for our purposes. One of the problems in replacing the wire is the holes in the arbors are not always drilled straight in, so it is necessary to reinsert the wire then bend it between centers until the arbor runs true. If the wire is not a tight fit then epoxy may be necessary. A small amount of epoxy pushed into the hole then insert the wire, this usually works well and never shows.
 

Harv

NAWCC Brass Member
May 12, 2010
14
1
3
Benton, PA
Country
Region
Thanks Jim & John for both comments. I was wondering if alittle epoxy would help if I can't get a tight fit. I will explore both options. Thanks again!
 

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