Waltham Equity pocket watch question

Danh · February 29, 2020

Hi Guys

for some reason buying a mainspring that is the correct one for an “Equity” seems quite difficult as the world of Waltham mainsprings appears to be a minefield

movement looks like the one pictured, I thought I had the correct one with a hole in the end, but I am sure it is slipping after a few winds

thank you

MrRoundel · March 1, 2020

Serial number shows it as a 3/0 size Waltham Equity. My Waltham parts book from shows the 1907 "O" size, which I believe shares parts with the 1907 3/0, as having a mainspring number of 2230. The 2228 is for the model 1900 "O" size, and is narrower/shorter and thicker. The serial number shows as a 1907 model 3/0 in my serial number book. Good luck.

Danh · March 1, 2020

2 hours ago, MrRoundel said:

Serial number shows it as a 3/0 size Waltham Equity. My Waltham parts book from shows the 1907 "O" size, which I believe shares parts with the 1907 3/0, as having a mainspring number of 2230. The 2228 is for the model 1900 "O" size, and is narrower/shorter and thicker. The serial number shows as a 1907 model 3/0 in my serial number book. Good luck.

Thank you - most appreciated

MrRoundel · March 2, 2020

You're welcome. I hope it helps. Cheers.

JohnR725 · March 2, 2020

When working on American pocket watches there are helpful procedures. There is the pocket watch database found at the link below which will give you all sorts of helpful information. Except I noticed a minor problem with your watch? Usually other people have pictures as examples of their watch and no pictures this time? Although that may be because people are not grasping who actually made this watch. Then normally on this site especially with Elgin you can get parts listings but I notice there is no parts for your watch? At least listed on the website.

Then I'm going to overload you with technical information and pictures before we get to the classic problem of waltham steel mainspring barrels and why the spring will never hold out of the package. Okay it will hold if it's an original spring. Then yes this discussion has occurred somewhere in this group before.

So in my procedure of always measuring the mainspring and comparing to the new has another purpose. One of the images I attached shows a minor problem at one time. Usually or a lot of times a single mainspring part number will refer to several mainsprings where the strength is different. Unfortunately or fortunately today that problem is solved. The modern white spring is always stronger for the same thickness then the blued steel original spring. Then the modern mainsprings typically don't have all these different thicknesses plus sometimes getting modern springs to replace original is just hard because they don't exist anymore.

So the classic problem is the shape of the end of the spring is incorrect and that means it's never going to catch unless you buy an original spring. Sometimes you can buy original springs and strangely enough there still good even though they are very old. I've attached a couple more images one am slightly exaggerated but if you look at the end of the spring it has a bend. look at the spring that came out and see what the end looks like? So the modern spring is just a hole punched in that is never going to catch. Trying to bend end of the spring can be problematic because sometimes it has a habit of breaking. A compromise is to file the shape that I have in the other picture basically a taper that can catch on the hook if you're lucky. Otherwise you can do what I do is give up and go to eBay and see if can find an original spring.

https://pocketwatchdatabase.com/search/result/waltham/21699347