French movement help

rfh11

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Dec 13, 2008
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I disassemble a french movement by Vincenti. The works were cleaned and inspected to the best of my ability. No problems found. The movement was working prior to taking it apart. After assembling the works and oiling I noticed that when I move the minute hand forward I am meeting higher resistance at several points around the dial. The sound level of the beat increases at the lower resistance areas and becomes lower at the higher resistance areas. What should I look for? The pendulum has very little swing. If it makes any difference this is a open escapement with jeweled pallets. Also, one last question. Why is the plate stamped VINCENT and not Vincenti.

Thanks,
Randy
 

shutterbug

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Oct 19, 2005
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Sounds like a bind in the motion works. Maybe a pressure washer or heaven forbid, something bent. Could be the hour wheel too. I'd pull the hands and hour wheel off, and the snail if it has one and see if it runs. That would narrow down what to look at.
 

Scottie-TX

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Apr 6, 2004
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As SHUT advises - inspect the motion works - the wheels that drive the hour hand - for binding. I believe the minute cannon is friction fitted to the centershaft and it is very common with this type fit to have varying resistance as the hand is turned. It will not affect operation of movement.
Loudness of beat increases when turning hand because you are adding power to the movement from the centershaft. Changes in beat loudness while turning hands again will not affect reliability.
These short pendulum roulants typically do not have a wide pendulum arc.
What is important, that teeth land on top of pallet radius. If they fall short of the top, then lock is not complete, recoil will be present, and impulse will be small, resulting in poor operation..
A CLOSEUP picture of open escapement will help us to diagnose the escapement.
 

Mike Phelan

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Dec 17, 2003
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Bent minute wheel pivot? Careful - they are glass hard! The cutout on the cannon pinion sleeve can be adjusted to give more or less friction for hand setting.
 

Dave B

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Jun 7, 2008
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Check to make certain the hour hand is on far enough so that the minute hand is not binding on it at the post.
 

Dave B

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It is surprising how often I run into this on the clocks I overhaul. I put the whole thing together on the test stand, without the dial, and everybody is happy. I then put the movement in the case, and discover that when I press the hour hand far enough onto the pipe to relieve the back of the minute hand, there is dial interference. Examination on a granite surface block nearly always shows that that either the minute hand is dished at the bushing, or that the hour hand is not truly perpendicuar to the pipe; or both.

My granite surface block is a 6"X6" square of countertop granite, sold as a sample. It isn't as perfect as a machinist's surface block, but it is close enough for most work, and was a heck of a sight cheaper than buying a surface block from one of the machine shop supply houses.

Maybe I should have posted this under "tools". ;)
 
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