Repost From Watchmaking Subforum

[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.

It was recommended that I repost this question here for more visibility:

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]

yeah will see the mods can combine the two here for now

their was a lad thinking on it was it @Dimman ..who had a lot of this stuff as he was making and building one of his own worth checking his threads not sure if they was in central or could be in the mod /res./diy sub forum ..might try to locate some of them if I get chance


this was the lad

Adventures in case-making.

did other threads but off the top of my head can't think which sub they was in but search might gain you some efforts as sure their was a dozen or so threads done on various points from cases, movements , dials etc etc ....

[tribe125]

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.

You’re very welcome, but those are pretty advanced questions, and most of us are consumers rather than technicians.

A good resource for watch movements is www.ranfft.de, but I don’t think that can answer your questions.

The classic tome on watchmaking is ‘Watchmaking’ by George Daniels, which generally costs around £50 on Amazon.

All the best.

[is that my watch]

You’re very welcome, but those are pretty advanced questions, and most of us are consumers rather than technicians.

A good resource for watch movements is www.ranfft.de, but I don’t think that can answer your questions.

The classic tome on watchmaking is ‘Watchmaking’ by George Daniels, which generally costs around £50 on Amazon.

All the best.

yeah that was my call in the other thread well ranfft any way

hmmm would matt have any info maybe ?

[skywatch]

Indeed, most of us here don't know the answers to your questions. However, may I recommend that you purchase an affordable un-cased movement and study it yourself, break it down and measure the parts in question with a good pair of digital calipers? You might start with a Sea-Gull ST3600 for example, which is basically a copy of an old pocket-watch movement (similar an ETA 6497), therefor a bit larger and easier to work with.

Back when I thought I wanted to learn how to clean and service movements, I went online and bought several very cheap Chinese watches, usually around $10-20 on eBay and surprisingly functional. They were cheap enough to allow me to take them apart and learn how they go back together. I decided I didn't want to pursue it further though, and gave those watches away, but the exercise helped me to understand the workings a bit better. It would be easy enough to measure the innards of such watches and learn some standard practice.

Enjoy your project!

[is that my watch]

Indeed, most of us here don't know the answers to your questions. However, may I recommend that you purchase an affordable un-cased movement and study it yourself, break it down and measure the parts in question with a good pair of digital calipers? You might start with a Sea-Gull ST3600 for example, which is basically a copy of an old pocket-watch movement (similar an ETA 6497), therefor a bit larger and easier to work with.

Back when I thought I wanted to learn how to clean and service movements, I went online and bought several very cheap Chinese watches, usually around $10-20 on eBay and surprisingly functional. They were cheap enough to allow me to take them apart and learn how they go back together. I decided I didn't want to pursue it further though, and gave those watches away, but the exercise helped me to understand the workings a bit better. It would be easy enough to measure the innards of such watches and learn some standard practice.

Enjoy your project!

well you can buy running st36 Chinese version of the asian 6497/8 version of a eta for like £30 quid new to work on just as much for the same sorta price in away

their is something at the back of my head saying THEIR IS A THREAD with a lot of list and such like of type size hand sizes pinion sizing etc etc some where on here

just dammed if I remember where or the title of it

[Strela167]

Had a quick google

https://www.google.com/search?client...ering+drawings

some info around , if this helps.

[is that my watch]

thinking about it @Chicolabronse may have answers as he work with watches he now designs so may have a idea of these when looking for movements for his watches maybe

[aphocks]

Thank you everyone for your generous and kind responses, I have never been welcomed so well into a forum before! I have purchased George Daniel's book and I am waiting for the delivery now, as far as online drawings I found quite a few random drawings with dimensions through some creative web searches, however none of them are consistent with each other. I'll just have to use my best judgement for now I suppose. I am also currently poking around to purchase a few movements, seems like going straight to the horse mouth is going to be the most efficient method.

[is that my watch]

Thank you everyone for your generous and kind responses, I have never been welcomed so well into a forum before! I have purchased George Daniel's book and I am waiting for the delivery now, as far as online drawings I found quite a few random drawings with dimensions through some creative web searches, however none of them are consistent with each other. I'll just have to use my best judgement for now I suppose. I am also currently poking around to purchase a few movements, seems like going straight to the horse mouth is going to be the most efficient method.

yes depends how you go about it mean even some of the small business use off the peg movement sets normal when we did our own forum watch we had certain ideas in mind

of size and shape so that would limit choice

as it turn out we use the case and movement from a airforce chrono so just left the design of the dial but in chats turns out this is much the norm really

so yes think it's get the idea sorted first.

then see what matches would say chat to hk but he ant been on in forever but he dealt a lot with movements as he was in the trade and put it all together and made them for us