Wristwatch Part Dimensions

[aphocks]

Hello all, I am a mechanical engineering student, I was hoping I could ask some questions here about your art for a project I am pursuing. I would like to start off by saying that I mean no disrespect by coming into this forum and asking questions that should be earned with experience and research. This is a journey for me and I think that while I am not as knowledgeable, we certainly share common ground in our passion for mechanisms. With that being said I have some technical questions that I have had a really hard time finding definitive answers to.

I am working on potentially presenting a wristwatch I have been designing as a senior project. I have spent three months so far learning all that I can in the horological field and I think I can start making some more technically specific drawings in CAD. I would be more than happy to share any details about my design process, as I don't have any illusions that I possess some grand idea on this topic. The questions I have are as follows:


1) What are common gear wheel thicknesses for going trains in wristwatches?
2) What are common K values (Spring constants) for mainsprings?
3) What are common shaft diameters for gear axles?
4) Is there a universal standard for jewel diameters and thicknesses or does it vary depending on which gear they support (I have jewel dimensions but I don't know what sizes to use where)?
5) Which jewels need to be in shock absorbing cages vs just press fit into the frame?
6) What is a common number of turns to fully wind a mainspring barrel?
7) Are there any good books or websites where I can view schematics that include dimensions of wristwatch parts?

Some dimensioned prints of common movements would be very helpful as well.

[is that my watch]

would say normal you have posted in the right place but think maybe a mod could bump you to central with this thread so more may see it and add post as not much traffic in here

and not my sort area of knowledge

[rodia77]

I don't know the answer to any of your questions, but .

Perhaps a good place to start would be compiling a list of popular/common movements and simply Googling images for '<movt_name> schematic'? When I did that with ETA 2824-2, quite a few technical drawings do pop up. Movement manufacturer sites is another idea, but I'm not sure if they provide detailed schematics to the public.

[is that my watch]

but saying that

this is my bible on vintage movements

http://www.ranfft.de/cgi-bin/bidfun-...ranfft&2&2uswk

[is that my watch]

I don't know the answer to any of your questions, but .

Perhaps a good place to start would be compiling a list of popular/common movements and simply Googling images for '<movt_name> schematic'? When I did that with ETA 2824-2, quite a few technical drawings do pop up. Movement manufacturer sites is another idea, but I'm not sure if they provide detailed schematics to the public.

bidfun sorta does that

Fig. 1 Fig. 2

AHS 56 Features manual wind sweep second date Data 10.5''', Dm= 23.7mm, Do= 24.35mm H= 5.65mm F= 1.15mm T= 2.7mm 2/3 jewels f = 18000 A/h power-reserve 37h Balance staff U1428 / U2607 (staff with slot D= 0,6mm / 0,55mm) U2512 (single roller) U3118 (double roller) Stem W2238 Mainspring / battery Zf1391, 1.70 x 9.0 x 0.12 x 240mm Hands 1.42 x 0.80 x 0.21mm

Remarks pin-lever escapement ratchet on dial side, crown mechanism with rocker bar balance versions: staff with slot, single roller, double roller The distance between balance bearings is adjusted either by the common screwed point bearing on the dial side (cf. AHS 40), or more sensitive and service-friendly by a screw bending the balance cock or -bridge (Fig.1). Late samples have a balance bridge instead of a cock, and are signed on the dial side as AHS 42. It is not yet known, which variants were made with this layout. Often a wrong or no calibre signature is present. family: 40: sub second, pointed staff 41: sub second, pivoted staff 42: sweep second, pointed staff 42(CLD): sweep second, date, pointed staff 43: sweep second, pivoted staff 43(CLD): sweep second, date, pivoted staff 44: no second, pointed staff 45: sub second, jewelled pointed staff 46: sweep second, jewelled pointed staff 47: no second, jewelled pointed staff 54: no second, date, pointed staff 56: sweep second, date, jewelled pointed staff Example, year: signature; shock device ca. 1975: - AHS, 42 (AHS 54, without second)

[aphocks]

I don't know the answer to any of your questions, but .

Perhaps a good place to start would be compiling a list of popular/common movements and simply Googling images for '<movt_name> schematic'? When I did that with ETA 2824-2, quite a few technical drawings do pop up. Movement manufacturer sites is another idea, but I'm not sure if they provide detailed schematics to the public.

This actually does get you some helpful results, I suppose this, and the other resources mentioned will have to get me close enough and I could fill in the gaps myself. Thank you for the suggestion!