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Sicura D500 Jump Watch Release mechanism

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Hi, I'm new on here. Have just won a Sicura D500 Jump Watch on ebay. It looks battered from the pictures (yet to arrive) but it is working. I still have my 1973 Sicura, from when I was 11. The hands had fallen off and the mechanism stuck and so I left it for years. My original plan is to use the best case and crystal, take the face from my original and attach it to the working mechanism, and use the new red and white hands. But then I realised that I had never taken the back of the original watch off, so the hands must be inside the case, maybe jamming the mechanism.

So I gave it to a friend who's really looking forward to getting his hands on the watch and learning what makes it tick (apologies for the unintentional pun) but when he unscrewed the back he wasn't sure how to remove the mechanism from the case. He said to me something along the lines that he was looking for a release plate, but couldn't find it, so wondered if it was a block and something, and he didn't want to pull at it, in case it was the wrong thing to do!

Does anyone have any ideas on how to release the mechanism from the case? Many thanks.

Also I'd be grateful for any other tips on polishing out the glass and case. Enclosed is a photo of my original watch.20170408_204519.thumb.jpg.7566a4c1d0d15e

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Hmm, I am worried for the health and safety of your Sicura !!

Has your friend removed the winding stem? That needs to come off first. Has he got proper precision screwdrivers? To remove the stem he will need to loosen (not too much or he will disengage totally) the tiny screw highlighted in the picture below :


Then prise out the movement holder (tabs round the edge) and the movement will then be free to come out.

You can then play hunt the second hand (there is of course only one 'hand' on this model.). However I would be surprised if it has managed to make it's way somewhere to foul the mechanism.

To remove the face, there should be a couple of again very small screws on on the outer edge of the movement that hold in place posts on the back of the dial. Loosen these then gently prise off the face.

Good luck. It can so easily go horribly wrong in inexperienced hands.

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Many thanks for the message. Didn't get a notification that you had. He opened the back, had a look, couldn't see what he was looking for and decided not to force anything and do research :-) I decided to do likewise, joining this forum and watchrepairtalk. I bought a 2nd watch from ebay for a great price, as it's in better condition than the photos suggested. The movement works and keeps time. The only problem seems to be the date changes between 15:00 and 16:00! Suggestions are the mechanism is BFG 866 and I have found a couple of really great videos to show him the insides.

Regards the missing "hand", I can't ever remember taking the back of the watch off when it stopped working back around 1973 or 1974. Being aged 11 & 12 things got rough at Break time at school, and I wonder if it got knocked off, along with the crack in the crystal? We'll find out one way or another. I'd like to put the original face onto a working mechanism, into the cleanest case and cleanest crystal, so we'll see how that goes.

Thank you for the reply, and if anyone has tips on cleaning or polishing the glass or case, they'd be much appreciated. I'll keep people posted on this thread on how things proceed.

Below is a photo of the 2nd watch, and I still have the original case the watch came in. I'm sure I can reproduce an insert similar to the one that has deteriorated. I only wish I can remember what strap it had. I'm sure I selected the watch from the 1973 Spring/Summer Empire Stores catalogue, or possibly Grattons. Any suggestions as to what it might have been appreciated as always. PS apologies as I cannot seem to get images embedded in the post.






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Not much can be done to the case without appropriate equipment, probably would need replating, not financially worthwhile..

However scratches (not cracks) in the acrylic crystal can be easily removed by polishing with Brasso, ideally with the movement removed in case of ingress of polish.


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