I am working on a 19J Vanguard. This watch was dead when I recieved and today it is running. There were several issues including a bent fork that are now corrected. I am trying to understand why it is loosing so much time. Last night at 10:00 I set it to an atomic clock. This morning it was nearly 30min slow. Loosing 3min per hour?? Who knows what was changed through out it's life. Should I start removing balance wheel screws? Any ideas or suggestions would be appreciated.

Regards

...Bob, am wondering whether or not you have a timing machine?...in this day and age it is almost imperative that you have one in order to time a watch..to begin removing balance screws or altering mean time screws is a 'needle-in-a-haystack' operation without one...then too, there is the issue of a 'loose' cannon pinion as a possible cause as well...I use the Model 3 Mumford Microset Clock/Watch Timer w/excellent results...Jim

Jim, thanks for the response. I do not have a machine at this time but it will be in the very near future. I use a friends when avaiable. I was told not to move the mean screws. I'll check the cannon tonight but as I remember it was tight. There were timing washers already on the screws. The darn thing looks like it has great motion and by ear it sounds good. May just be time to treat myself to a good machine!!

Bob, Did you put in a new mainspring? If not, a tired (set) mainspring can cause this to happen. THe weak mainspring causes the balance to have just enough less swing to cause the timing loss.

Tom

Tom, I did not change the mainspring. I'll do that tonight and advise. I does make sense once you know enough to think about it!!

Bob, I wouldn't recognise a Vanguard if it jumped off a table and bit me, so forgive me if my input turns out to be dumb!

The bent fork suggests to me, a major mainspring breakage at some point and possibly other train damage!
If the spring was replaced with the incorrect type, there's a danger of it being swapped 'like for like' for another incorrect spring which will replicate the same problem over!.
May be worth checking dimensions.

Tom, I always have problems getting my head around the effect of mainspring power on balance amplitude and hence timing.

If the spring is weak, the impulse imparted by the roller will be weak and the amplitude of the balance reduced accordingly (won't swing as far).
If the spring is strong, the impulse at the roller will be strong and therefore the balance amplitude greater (will swing further or have I got it totally wrong???)

My tired engineers brain tells me that if the balance amplitude is low, it won't swing as far in comparison to one having a greater balance amplitude, which in theory means the roller will trip the fork more frequently and hence cause the watch to gain in time, and conversely, a more powerful spring to cause a loss of time due to the balance moving in a bigger arc creating a longer period before the roller trips the fork?

I'm probably going to look a complete wart if I've got it totally wrong, but if anyone can impart some explanations of the effect of mainspring force on balance amplitude without hi-jacking Bob's thread, I for one would much appreciate it.

Regards to all

John

Bob Jim is right a timning machine is a must if you work on watches very much,,there is one thing you can do that won,t cost you much get a cheap quartz watch that will stop running when you pull the stem out or as it is called in the old watches a hack set,stop the second hand on the quartz watch at the 12 postion then when your pocket watch second hand gets to 12 start the quartz wacth and let both run for 5 minutes and see how much slow or fast your watch is then multiply by 12 and that will let you know how much off it is in 1 hour,,low tech i know but will give you a good idea how much slow or fast you vanguard is..

Changing screws or undercutting screw opens up a can of worms after doing so there is the problem of getting the balance back in poise belive me you can get into a worse problem than you now have..If you are only off a few minutes a day you can most of the time correct that with the timning screws..

Samie, I guess the same thing. I will go ahead and change the mainspring first. I want to see how much difference it will make. If I make any changes to the hairspring should I look for another or shorten this one? I am thinking that if it has fewer coils then it should pick up time? Make just another can of worms. The thought has crossed my mind to call this hobby "worm raising" !!! LOL

If nothing else this watch has been a good lesson. The pipe came off of the second hand when I first took it down. ( restaked "feelin good about that one ) next the fork was tweaked and got that back, hey, even with out breakage!!
Took balance screws off and now back on, with out loosing. The next thing will be to look for a hairspring. Thanks, Samie I appreciate the advise. Bidding on a timming machine right now!!

I'm probably mentioning something obvious, but have you demagnetized the movement prior to timing it?

Yes, I have learned this lesson sometime ago. Nine minutes to go on the timming machine!!
I also will double check to see that the saftey is clear of the table. After tweaking that for it may have moved less than a hair. I'll have to post some pics when I get it running right.

I guess I could send it to Ebay world and be like the ones I see "runs but not timed" LOL. I just like the challange of getting it RIGHT!

Bob how many timning washers are on the balance, your watch is running slow by removing the timning washers it should speed up...I guess you already know these are put on in pairs straight acroos from each other so your balance will stay in poise so they will have to be taken off the same.

It is hard to say for sure about the hairspring without seeing the watch but i can tell you this trying to change the lenght of a hairspring is quite a job and takes a lot of pratice ,,not a simple or easy thing to do,,,.

Good luck ain,t these watches fun,,when you are about ready to pull your hair out put the watch off to the side go drink a cup of coffee and come back later.

Bob: How in the world do you stake a pipe back onto a second hand? I need to know this. Thanks

Samie, that is exactly what I did. Later I will get back in it and dig deep.

Mark, first of all I learned a lesson. You can only do this on the second hands that are brass tubed. I tried to fit a steel one that took forever and nothing worked. On this watch when I pulled the second hand the pipe was on the pinion and the hand was on my puller. I carefully took the pipe off the pinion and set it on my staking bed. I was lucky to have the correct hole that just fit. Place the second hand back on and lightly swaged the metal with a center punch. Then to be sure took a screwdriver and nicked the top over on two places. It looks better than super glue!!