Theoretical questions about movement sizes in GPF homages

[Rotorua]

Here's an uninformed couple of noob questions for you guys. It might be absolute common knowledge to the pros, in that case, lecture me and then give me the dunce hat to sit in the corner for a while. But don't laugh, I'm trying to wrap my head around a potential fantasy build.

I know what the usual suspect movements for GPF homages are - Mollys, Corteberts, Unitas, Angelus,... I also know their sizes, which seem to run at or around 36mm (16 ligne). I've come across quite a few absolutely stunning movements in vintage american pocket watches though, that would be beautiful in a display CB. Waltham, Elgin, Keystone Howard, Rockford... Their sizes can go quite big with size 16 (19''' 1/4, or 43.4mm) being prevalent for the older pieces. That said, there are many size 12's and below (17''' 3/4 or 40mm and lower) that would theoretically fit into a 47mm case. At least that's how my beginner thinking goes - don't forget, I know just about the bare basics about movements, other than enjoying to look at them for hours.

Question 1: What is the maximum size movement fitting into a, say, 6152/1 case? Or a Bettarini, or a Fiddy 47mm case? Apart from the fact that I'd likely need a custom movement ring.

Question 2: Their setup is usually: crown at 12, second subdial at 6. Can I theoretically turn the movement 90 degrees clockwise for a potential build? Are there any implied problems doing that, seeing that the balance would now sit in a completely different position than it was originally made for?

Question 3: What are other possible implications/troubles here? I can think of a few - Movement being too thick, distance of second to hour not fitting a conventional dial, dial feet not in the correct position (duh), cannon pinion height and hand hole diameter, different diameter winding stem...

This would absolutely NOT be my first attempt at a build. You know, learn to crawl and walk before you run, etc. But would I like to attempt it in the future? Hell yes I would.

I appreciate your insight & information.

[djolemag]

Welcome aboard!

Short answers:
1. Depends on case, don't know exact dimensions. In most cases you would need custom made movement ring...
2. No impact on balance... Only oyu wil have potential trouble with distance between center and subseconds, dial feet etc..
3.
a) Dial feet usual problem.. can be solved by resoldering them or gluing dial with double sided adhesive tape/dots/stripes.
b) Height of CP/HW, can be short for some thick dial.
c) Hands fitting, finding proper hands or making them... Hole diameter and hand's length to fit the dial size/design
d) Stem height to fit the case could cause problems sometimes
e) Stem thread... Usually crowns are 1,2 mm threaded, old movements may vary, from 1.0 to 1.6 mm... So you must re-thread the stem or invent something
f) already mentioned, movement ring to hold it tightly in case, usually needs some tweaking...
g) sometimes movement is too big so no need for ring... Then you must find a way to hold it in case properly, without shaking or moving
h) sometimes you can find a movement which can "almost" fit into case... Then you have to slightly trip inside diameter of case.. Pain job without proper tools and skills. Be careful to always measure correctly...
i) dial... finally you end by making your own
j) time: get ready to spend a lot of time to finish one proper build. You should make perfect planning, measure everything 10 times, draw/sketch, check again, all that before you start...


This is compete list, at least what I can say at the moment.. I'm sure I missed something...

[EP.-]

In my understanding:

Question1. The usual 47mm case takes up to 39mm movements
Question2. No problem with turning the movement provided you will not use the dial of that movement.
Question3. All the problems that you enumerate plus the alignement of the hole for the stem in the case and in the movement. Fitting hands holes with the pins of the movements.

[kilowattore]

Yes, point 3 should read like all that you mention + all that EP mentions + something unforeseeable, at the same time

[Rotorua]

[mention]djolemag[/mention] hvala brate, I really appreciate your time to answer everything. I did think it will be hard, but where is a will, there is a way. I will need a few years to build my skill set and practice on a couple of builds first, as well as slowly get all the tools together that I need. Also to take the time and really understand what cases are available on the market, and what better way than to build things!

@E[mention]EP.-[/mention] thank you, that definitely means that the case will need some rework. I’ll need to find out who is out there to do that, as I certainly don’t have the tools (yet). That’s half the fun - chasing after every piece of information when you have found a new hobby and a new forum.

@E[mention]kilowattore[/mention] that’s what I figured as well, and I’m at the point where I don’t even know what I don’t know. So it’s going to be a fun few years!

[EP.-]

All the task is simplified by chossing compatible components.

For example, a 6498 or ST36 movement, a case for that movement (there are a lot), a dial for the case (they are a lot), and hands for this type of movement (you have a lot to chosse).

Once the 6497/8 build done, you can try a rolex type build with an assian 2824 or 2836 movement, and case, dial and hands compatibles.

Once you has build some watches with compatible items, you can add more dificulty by incorporating some non compatible item in your following builds.

[djolemag]

All the task is simplified by chossing compatible components.

For example, a 6498 or ST36 movement, a case for that movement (there are a lot), a dial for the case (they are a lot), and hands for this type of movement (you have a lot to chosse).

Once the 6497/8 build done, you can try a rolex type build with an assian 2824 or 2836 movement, and case, dial and hands compatibles.

Once you has build some watches with compatible items, you can add more dificulty by incorporating some non compatible item in your following builds.

Agree +1

[spade_lt]

Did I miss or did nobody mention, that most vintage american movements are negative set - and that's the biggest problem with them...

[Rotorua]

All the task is simplified by chossing compatible components.

For example, a 6498 or ST36 movement, a case for that movement (there are a lot), a dial for the case (they are a lot), and hands for this type of movement (you have a lot to chosse).

Once the 6497/8 build done, you can try a rolex type build with an assian 2824 or 2836 movement, and case, dial and hands compatibles.

Once you has build some watches with compatible items, you can add more dificulty by incorporating some non compatible item in your following builds.

Thanks mate, that was my thought process as well. Learn to crawl, then learn to walk, then learn to run.

[Rotorua]

Did I miss or did nobody mention, that most vintage american movements are negative set - and that's the biggest problem with them...

Interesting, until you mentioned negative set movements, I did not even know they existed. Thank you for the insight. Very interesting concept though, and it makes sense historically speaking - the movements could be cased in easier that way, and it would be easier to switch to another movement manufacturer. So I researched a little bit, and here's a very good explanantion I found if there are other newbies interested in it: http://www.vintagewatchstraps.com/watchmovement.php (scroll down to "Negative set or "American" keyless work")

It seems that the negative set movements were more often used in the 16s and bigger movements, and perhaps not so much in the 12s size.