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Posted

I got hold of a trench watch from eBay with the aim of getting it running.  Seems a pretty standard movement, but in dismantling I broke the screw off the barrel arbor.  Not sure if it was reverse threaded - I tried both ways with no joy before applying to much brute force and the head came off.

I'm left with a broken screw in the arbor which I cant see how to shift.  I don't think those broken screw tools will work because the other end of the arbor is closed.  There's no shaft that I can grab with pliers.  I don't see that I can drill it out - I tried but it's too small and I couldn't get a start on it.  I don't have a lathe.

I have no idea what the movement is - there are no numbers on it.  I was thinking the best way forwards is to get a replacement barrel and arbor of the same size.  I've measured it all up.  Any ideas how I can find a matching movement as a donor?

Posted

Well, don't be shy and show a picture of hte movement - somebody may recognize it.

You can cut a slot in the remain of the screw thru the arbor. You can cut to where the square part of the arbor ends and bearing pivot begins, this will not make harm to the arbor. Now that the head is broken, the screw is not tightened any more and should unscrew with ease.

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Posted
16 minutes ago, Bonefixer said:

That’s a great idea. I’ll drill a hole into a bit of scrap wood to wedge the arbor in, and then cut a slot with a Dremel. 
 

I’ll report back. 

What will you use in the dremmel to cut the slot ?

Posted

You're quite right. Don't have anything suitable with my Dremel. I'll look into Jewelers saw blades. 

Here's the movement (well a bit of it) in case anyone recognises. I've stuck the arbor in the barrel for display purposes. 

IMG_9668.jpeg

Posted

These carborundum separating disc are extremely delicate and break at the slightest sideway pressure. You'll need a high precision handpiece with minimal chatter and high torque at low speeds. I don't think a Dremel will fit the bill.

A diamond disc would be a better option. 

New Dental Ultramicro Double Sided Diamond Cutting Disc for separating polishing ceramic crown plaster or jade
https://a.aliexpress.com/_mqMNFea

 

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