Jump to content

Recommended Posts

Hello all,

I am working on a Tissot pocket watch (model 501, calibre 43) which dates to 1952. It was missing the crown and stem. I was able to source a new stem for the movement and confirm it fits correctly. However, I am having a devil of a time trying to find a crown that fits. The stem has a diameter of 1.45mm and all the parts houses I have checked seem to primarily have crowns to fit 0.90mm and 1.20 mm stems and a small number to fit 1.40mm stems. Would the 1.40mm crowns work or am I missing something here? Other relevant dimensions my application are case tube OD of 3.60mm and I think an overall crown diameter of ~ 8mm would be in good proportion for the watch case. Any advice would be appreciated. Thanks.

Link to comment
Share on other sites

This may be a shot in the dark, but would you happen to have a die plate (for threading screws) that you could use to measure the tap size of the stem?  It will give us a number we can use.  I could dig through my store of old crowns.  Yours will be trapezoidal ("pumpkin" as opposed to "onion").

I got to thinking, if you had the tap and die set, then you would probably know to locate a large enough crown to tap to size.  Oh well.

Either way, it can be done.  If a crown can be found that is a good fit for the pendant and its sleeve, it can be tapped to the correct thread size if need be.  I have done it before.

  • Like 1
Link to comment
Share on other sites

That looks like a good match and I think he 7.82 diameter would be in proportion to the rest of the case. One question… Could you measure the overall height of the crown, including the threaded part  that sticks out on the bottom? I just want to make sure it won’t interfere with the bow vertically. If the dimensions are in order, is this something you would be willing to sell? Thanks

Link to comment
Share on other sites

51 minutes ago, KellyZ said:

That looks like a good match and I think he 7.82 diameter would be in proportion to the rest of the case. One question… Could you measure the overall height of the crown, including the threaded part  that sticks out on the bottom? I just want to make sure it won’t interfere with the bow vertically. If the dimensions are in order, is this something you would be willing to sell? Thanks

Sure

2022-11-21 14_20_50-20221121_141207.jpg ‎- Photos.png

2022-11-21 14_20_36-20221121_141251.jpg ‎- Photos.png

Link to comment
Share on other sites

Thanks for all the replies.

LittleWatchShop, I took some measurements and I dont think there would be any issues with vertical clearance. After thinking about it, my concern with that crown would sit on top of the case tube and even if I cut the stem length carefully, there would still be a gap which would allow dust and water ingress. I am thinking I need a crown with no post and an opening slightly greater than 3.60mm so that it can fit over the case tube to minimize that. Please let me know if you disagree.

JohnR725, thanks for the links. I did come across those while doing my research but they (and other pages I found) only go in .1mm increments, 1.1, 1.2, 1.3, 1.4, 1.5 etc. My stem has a diameter of 1.45mm, checked with both digital calipers and micrometer. Is there a standard to step up or step down to calculate the tap needed?

KarlvonKoln, the largest tap in my set is 1.2mm so I dont have one big enough. I did look around and individual taps can be had without spending a great deal of money. I would not be opposed to investing in one and trying your suggestion. The learning experience would be good if nothing else. The same question applies though... what size would I need. I do have a couple of crowns in an assorted box I have that would be good candidates.

 

Link to comment
Share on other sites

5 hours ago, KellyZ said:

would allow dust and water ingress

You obviously haven't seen a vintage pocket watch. It's amazing what will get past the crown and as far as I know pocketwatch crowns are never waterproof although usually pocket watches don't get in water even though you will find Rusty pocket watches because the entire case is not water resistant at all

5 hours ago, KellyZ said:

My stem has a diameter of 1.45mm, checked with both digital calipers and micrometer.

The funny thing about the screw thread diameters are they actually the diameter you measure? For instance is a website below like this one

https://www.windingstems.com/tissot.php

So we go there and we can look up your stem and then we get specifications. They have a different dimension than you have. Then just because I was curious I took the time to look up the bestfit stem It's specifications, and it has the same thing 1.5 mm is the diameter of the threaded part.

Then I'm being hunted by an image of pocket watch crown styles just can't remember where I saw that. But did find you this link may be a find something there.

http://www.julesborel.com/products/watch-case-parts-crowns-crowns-pocket-watches

 

tis 43 stem.JPG

Link to comment
Share on other sites

Definitely no expectations of waterproof, but I think an open gap (as opposed to a “S” shaped gap with a flush crown) would be just a little worse. I think with a straight gap, just the lint in your pocket would gum up the watch in short order. Thanks very much for that windingstems.com link… what a great resource, duly bookmarked for future reference. Taking a quick look, 1.5mm crowns don’t seem to be available from the big parts houses but I will spend some time searching on smaller suppliers. If I don’t find something suitable, I will invest in a 1.5mm tap and see what I can transform. Either way, I will report the result here.

Edited by KellyZ
Mistaken word
Link to comment
Share on other sites

7 hours ago, KellyZ said:

Taking a quick look, 1.5mm crowns don’t seem to be available from the big parts houses but I will spend some time searching on smaller suppliers.

Just a reminder about material houses.  Today 99% of everyone on this group the material houses an online business that you go you search the either have it or they don't order it and it shows up in the mail. But is that the way all material houses operate?

One of the problems is that not every single material house has converted to online. Then even some of the big material houses are not 100% online because it's hard to be 100% online especially if you have older stuff in limited quantity or you've acquired other material houses it's hard to integrate it all together. This means that there is a lot of watch material out there that isn't online.

 

Simplistically this means your crown exists it's out there somewhere but you're probably not going to find it online. Though have to inquire and in your profile no idea where you're located at all. In the US there are still physical material houses that do business with walk-in trade for instance or email trade. Even some of the online material houses if you read the fine print they will say email. But just as a reminder it depends on the particular material house as to how eager they will be to help you and some him get really cranky about wasting their time.

Link to comment
Share on other sites

Understood. I am in the US (Maryland) but am still new to this game so I will be learning which companies are less "cranky" as you put it when engaging in non-online business. Before I started going down that road though, I wanted to determine exactly what was needed (which I now have). I figure most of them would be impatient if I didnt. In fairness, they are there to make money, not to help me learn.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Restore formatting

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.



  • Recently Browsing

    • No registered users viewing this page.
  • Topics

  • Posts

    • Post some pictures , some good close ones of the parts you've described. 
    • Ive never used epilame H only information i have read and mentally stored about it mostly from Nicklesilver here and elsewhere ( the fork horns thing ), maybe the residue powder that is removed has some grinding effect ? So probably a good idea to limit its application areas to only the absolute necessary. Yes as far as i know epilame rubs off relatively easy, the technique of running the watch to make a groove through it first in the pallet stones where the lubrication is then placed. This i understand creates the barrier for the lube to sit up to. If i can find a good balance of pros and cons of its use then thats one process i can avoid by using a thixotropic lube on the stones. The epilame i would say allows for a more fluid lubrication to be used that would increase amplitude on low beat movements. The stearic acid powder is extremely cheap, the problem is the fuming process to coat parts, is not selective , the whole part has to treated in this method. If epilame residue can cause wear then thats not good, if I remember the conclusion was not proved entirely just a general assumption between watchmakers. The thread is out there somewhere, the same discussion is also old on a facebook group. Ive never used epilame H only information i have read and mentally stored about it mostly from Nicklesilver here and elsewhere ( the fork horns thing ), maybe the residue powder that is removed has some grinding effect ? So probably a good idea to limit its application areas to only the absolute necessary. Yes as far as i know epilame rubs off relatively easy, the technique of running the watch to make a groove through it first in the pallet stones where the lubrication is then placed. This i understand creates the barrier for the lube to sit up to. If i can find a good balance of pros and cons of its use then thats one process i can avoid by using a thixotropic lube on the stones. The epilame i would say allows for a more fluid lubrication to be used that would increase amplitude on low beat movements. The stearic acid powder is extremely cheap, the problem is the fuming process to coat parts, is not selective , the whole part has to treated in this method. If epilame residue can cause wear then thats not good, if I remember the conclusion was not proved entirely just a general assumption between watchmakers. The thread is out there somewhere, the same discussion is also old on a facebook group. If its a potential problem for amateurs to use then i would prefer not to take the risk .
    • Following on from my question about identifying screws in the AS2063 movement that basically fell out of the case in bits, I’m pleased to report that I’ve got it all back together, and the movement is running pretty well.    But… There’s something wrong with the keyless works and hand setting. It’s fine in winding and quickset date position - these work - but in hand setting position winding the crown turns the whole gear train.  I don’t really understand how it’s meant to work. It doesn’t have a traditional friction fit cannon pinion.  The second wheel is unusual with a pair of smaller pinions on it, which seem to interact with the barrel and the motion works.    Could this be the problem? I must admit I just cleaned it and popped it in place when reassembling the gear train. I’ve lubricated the pivots but didn’t do anything to the extra bits on the second wheel.    Does this make sense and is anyone able to figure out what I’m doing wrong? Thanks in advance, as always.    ETA - the parts list calls it the Great Wheel, not second wheel. 
    • You're thinking metal to jewel in general I guess. Maybe it would be a good idea to peg the pallet staff jewel hole on the main plate after the epilame treatment. I think that could work as it is my impression that the epilame doesn't sit very hard, but I could be wrong about that so feel free to educate me. I didn't remember that 9501 was thixotropic (thanks for the link). That would mean it's even runnier during impact (lower viscosity) so perhaps it's time I get some fresh grease as mine seems a bit too runny. What I have seen is a whitish surface after washing but it goes away if I scrub the surface with a brush in a degreaser (Horosolv). I don't think it embeds itself in the metal but sticks very hard to the metal. I don't worry too much about the cleaning solution. I just want perfectly clean parts and my solution can be replaced for little money (ELMA RED 1:9). Anyway, I quite often need "to strip back and rebuild" and scrubbing parts by hand isn't exactly the most stimulating part of a service. Just got confirmation that Moebius 9501 has a lower viscosity (68 cSt at 20° C) than 9504 (305 cSt at 20°). The viscosity of Molykote DX is 285-315 cSt at -25° to +125° C. I was surprised to see that the viscosity of Moebius 9010 (thin oil!) is higher (150 cSt at 20°) than my 9501 grease!
    • I’ve had a couple movements where it is clear the previous watchmaker was diligent with lubrication but the old epilam had turned to a fine white powder covering the pallet fork and keyless parts, which can’t be good for parts. I’m spare with epi since I don’t know how long it takes to degrade to that state…
×
×
  • Create New...