Jump to content

Stem extension help


Chopin

Recommended Posts

I have to use a stem extension on a Seiko Diver's with a screw down crown and I have some questions as I've never done this before.

First of all, how do you tighten the stem to the stem extension ? I know that I'll probably have to use a bit of glue but what do people do to tighten it ? Do you use a small vice ?

Second of all, I know that I'll have to cut it to length but how does one do it ? Trial and error ? Measure an approximate length and then just shorten it bit by bit until you get it right ?

Edited by Chopin
Link to comment
Share on other sites

I"ve used these before to good effect. I just put a crown on the extension and a drop of glue on the original stem. Now holding the original stem in a pair of pliers twist the extender on using the crown to screw it on. You don't need to use a lot of force. 

In terms of then shortening your new extended stem then approach this no differently than you would a normal stem situation. This is a great posting:

It''s sometimes necessary to shorten the original stem so that when the extender is fitted and shortened there's appropriate thread on the extender to fit the crown. Trial fit everything before the drop of glue!

  • Like 1
Link to comment
Share on other sites

That is one method that I was thinking of... Thanks!

At first I'm going to try and just trim the extension and see if it works, if not then I guess I'll have to trim the stem as well.

Another question which I forgot. How and what do you use to cut the stems and extensions ?

I don't have any special such tools but I do have the tools that you'll find in a normal household... Hope I have a pair of cutters with good blades...

Link to comment
Share on other sites

That is one method that I was thinking of... Thanks!
At first I'm going to try and just trim the extension and see if it works, if not then I guess I'll have to trim the stem as well.
Another question which I forgot. How and what do you use to cut the stems and extensions ?
I don't have any special such tools but I do have the tools that you'll find in a normal household... Hope I have a pair of cutters with good blades...
You may get away with just trimming the extension. As mentioned by "Watchmaker" Geo's article is just about the definitive work on this subject.
Wirecutters for the stem but the type you cut straight onto rather than to the side of the stem are best.
Try Cousin's or Esslinger, as they stock replacement stems suitable for Seiko that are threaded their hole length and makes life a lot easier

Sent from my SM-T585 using Tapatalk

  • Like 1
Link to comment
Share on other sites

I have a pair of straight cutters ... nothing special e.g. item P36103 from https://www.cousinsuk.com/product/end-or-top-straight-cutters# . You could use normal cutters just above the desired cutting mark and then gently file down any 'peak' caused by a non-straight cut to your mark. Because extenders are so cheap (around a pound for five) you can always practice on an extender itself i.e. cut and file on an extender and then check another extender will easily screw on. This may be a better option for you than buying special cutters if this is a one off job.

 

  • Like 1
Link to comment
Share on other sites

I do have extra extensions and an extra stem, just in case, but I'll try not to mess it up. [emoji3] Wonder if I have any good files... Could sand paper work ?
Sand paper [emoji16][emoji16]. You'll need a decent fine cut file. Remember when sized, to bevel the tip. This prevents stripping the thread on the crown when screwing on.

Sent from my SM-G920F using Tapatalk

  • Like 1
Link to comment
Share on other sites

Well, the good news is that I've managed to do anything required. The bad news is that with the extension (even trimmed out) the crown is now too long and I also broke the stem inside the crown.

Now I have to buy a new crown and stem as the old one didn't seem to actually fit, length wise, especially since I tried a brand new stem and it was a bit too short.

Oh well...

Link to comment
Share on other sites



  • Recently Browsing

    • No registered users viewing this page.
  • Topics

  • Posts

    • That's the right technique Mal 👍 If you are ok with a loupe ( which I'm not ) then pick up the dial in your left hand and make a tripod holder out of 3 fingers and then exactly how Mal and me described with your right hand, press and flick out the stem at the same time. You need three fingers to do this, i use my ring ring finger , sounds like mal uses his little finger, just whatever you feel comfortable with. The key point and dangerous side to this is the tweezers or driver slipping off the release screw. Stablise your left arm by resting your elbow on your bench, so that you can hold the movement horizontally flat, use a x5 loupe to view  and good light so you can see well and have a good tight fitting screwdriver to push the release down. Or as suggested a pusher mounted solid upside-down somewhere then all you need to do is push your movement up to it. I'll rig something up in a bit to show you what i mean.
    • Thanks Michael, shes a real soldier, it would take a tank to knock her off her feet.  Shes surprised even me and i knew she was a tough cookie.  Good for you Michael, you keep at it. I've been reading your posts re. your watchroom they're inspiring and it doesn't matter how long it takes you to get there its about the journey. Rome wasn't built in a day, our watchcaves are our solitudes, our own little empires where we can shut ourselves away from the crap that goes on around us in the world. I look forward to seeing you progress, I have my own ideas how i like to do things. But in answer to your questions on that thread, just let your workspace evolve around you and how you work. You wont figure it out straight away but you will know when to change it and when to leave it alone. But most of all just enjoy it.
    • That can be tricky. Sometimes I hold the movement from the edges in left hand and with right hand I push the release with tweezers and simultaneously pull the stem out with right hand pinky or something. 
    • I see what you mean. I must admit I’m not entirely comfortable with that but I can’t see a better method than what you suggest. I’d like to see something like this mirror with a short spike: https://www.cousinsuk.com/product/mirror-for-observing-movements Place it on, push the spike on the post with one hand and release the stem with the other hand. Minor problem, it doesn’t exist.
    • Hope you mum keeps on mending. I was adamant that I was going to get myself going after my stroke. I was only 52. I still have a lot of life left to live. Some people give up. Some people don't let it beat them. Your mum sounds like one of the winners. 👍
×
×
  • Create New...