As in many other fields, data is a very important matter. We have to find our spare parts, adjust the timegrapher to the correct lift angle, etc., so it’s very important to have the right data at hand.
So far, Generale Ressorts published a printed catalogue a very long time ago, and that’s still the only source of data when it comes to matching mainsprings with movements. There are some suppliers that have entered some of this data (Cousins, Ofrei, Boley) into their own systems, but a generally available list of mainsprings and where they fit wasn’t available anywhere.
As I’m a bit of a computer geek myself, I thought it was time to change that.
My first data project was to find a list of all winding stems and balance staffs, and to digitise that. The result is a searchable database for balance staffs and winding stems, also listing suppliers, and letting you search buy size. It’s at https://watchparts.org.uk/cgi-bin/watchparts.
My next project was a list of lift angles, which I compiled from various sources, which can be found at https://watchguy.co.uk/cgi-bin/lift_angles.
Last but not least, I attacked the mainsprings. GR gave me a PDF with all their products (8,800), and I put those into a database. Then came the larger problem of scanning and extracting the data from the printed catalogue, which gave me 14,624 different calibres and their mainspring, which I also loaded into the database.
The result is at https://watchguy.co.uk/cgi-bin/mainsprings, and this should be the ultimate mainspring list that is freely available.
If anyone wants the raw data for their own project, please let me know and I will let you have it if you publish the source.
Enjoy!
I think there is an error in this listing
Certina 25-661 RA1S05644 2937-X 1.20 0.10500 340 10.0 aut n2 GR Scan/WatchGuy
I believe it is a manual movement.
I had an occasion to search for this. The specs may be 1.2 x 0.12 xLength(?)
Thanks for pointing that out – I have removed the listing.
Thank you so much for your information kind regards
Hi Christian,
Thank you for sharing your data. Do you happen to know of a source of lift angles for Smiths (Cheltenham made) watches please?
Best regards
David
I am afraid I don’t.
This is awesome Christian! Thanks for uploading this 🙂
Hi Christian,
You may be interested in this link…http://www.vintagewatchstraps.com/mainsprings.php where you will find a reverse engineering calculator to help when the catalogue doesn’t have an exact reference. David here has entered the GR data into a spreadsheet and analysed it to create this.
Very generous of you to compile and publish this! I’d love to incorporate the lift angle database into Watch-O-Scope. BTW, I’ve never been able to find lift angles for Sea-Gull movements anywhere, and I see you haven’t either. 🙁
Nice to hear from you again! I hope all is well.
Give me a shout, and I’ll send you a CSV.