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Crown wheel.


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I have a Unitas 235 pocket watch that, until recently, was in fine working order.

Then, all of a sudden, things changed.

It wouldn't wind up, just a grating sound.

Inspection revealed that the crown wheel was lifting slightly when winding was attempted.

The (Left thread) screw holding the crown wheel down just turned and turned, never reaching 'tork.'

The screw thread is ok, (Very, very short, though. About 1.2mm) but the top of the (Brass) hole has a 'whisker.'

The rest of the hole thread looks fine.

Measuring the depth of the hole, reveals about 3mm of depth.

The screw (Before it zinged off out of the tweezers and into the great unknown for eternity!) measured a thread diameter of 0.98mm thick and the top of it measures 2.94mm.

It seems that a slightly longer thread would do the job, but where to get it from is the problem.

Cousins have Crown screws, but at just under £30 for a box of 100 plus post etc; that seems a little 'over the top.'

If I live to be 200 years old, I wouldn't need the other 99 Crown screws! 

Well, ok..................maybe one or two, then!

Any suggestions would be gratefully appreciated.

Thanks.

 

 

 

 

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Left hand screw? And the head of the screw 2,94? or 3 mm. Can take a look if i by any change have one? 

Hello, Rogart63,

Yes, those dimensions are correct.

If you have one that you can part with, that would be great.

Thanks.

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Hi, Rogart63,

From the dimensions that you provide, it seems that your Crown Screw would be a little too short to grab the thread a little further down.

However, I “Thank you“ for your kind offer of help.

Regards.

Len.

 

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Hi, Rogart63,

From the dimensions that you provide, it seems that your Crown Screw would be a little too short to grab the thread a little further down.

However, I “Thank you“ for your kind offer of help.

Regards.

Len.

 

http://www.ebay.com/itm/POCKETWATCH-CROWN-WHEEL-SCREWS-ASSORTMENT-x20-pocket-watch-parts-spares-repairs-/321721228406?hash=item4ae8145c76:g:AQAAAOSwpDdVJ9Rd

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