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Question about Waltham PW center wheel

Charlie Ryan

NAWCC Member
Dec 10, 2017
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Hi All

I'm trying to get a Waltham 1883 PW working. I'm just a wristwatch repair hobbyist with no PW experience. I was surprised to find threads holding the pinion onto the center wheel. Is it for ease of manufacturing or does it serve an operational purpose? I also notice that the threads are closer to one end of the pinion. Should that end sit on the wheel? I didn't notice which end was up when disassembling.

Thank you
Charlie

IMG_6635.JPG
 

Jim Haney

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Sep 21, 2002
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Charlie,

That is called a Safety Pinion, designed to unthread when you have a Mainspring failure. It saves the gear train from damage if the power let loose all at one time.

Look at this youtube on it.

 
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bruce linde

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Nov 13, 2011
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thx for posting the video explanation... not sure why it took five minutes to say 'the pinion is screwed on so it can unscrew in case of emergency to prevent damage' :)
 

Jim Haney

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Sep 21, 2002
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Bruce,

Yes, It was produced on a elementary grade school level, but it finally told us` what the meaning was........

With Youtube you have to use what is available :whistle: :eek: but I did learn how to adjust the valves on my Ferris zero turn mower.:clap:
 

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