Hi All,
Just wanted talk a bit about my waltham project I started this past Friday. Got watch in mail and for some reason I figured it had mainspring issue. It has a PUW 1560 movement and a completely different way to make hour jump. Now to the funny stuff. I have worked on several automatics but all up to now have had an automatic unit that came off in one piece. This one didn't and had to take off top plate slowly hoping for no surprises even though I could see a spring under there. Did that with no problems. Got to main plate underneath and it was one piece, no seperate barrel plate. Could not find a way to let down mainspring. No click or ratchet or even a screw to take off top winding gear. Well I've never been one let a minor problem like that slow me down. Decided to go ahead and just hold back barrel with my thumb. I had forgotten that I thought there was something wrong with mainspring in the first place. Anyway has anyone seen a watch explode? I was picking up pieces all over the room. Found them all and nothing was broken. Think what happened was that barrel had seperated a bit which was causing movement to not run and when the pressure from the plate was released k-blam. I had already looked up and found a similar movement because I was sure I needed parts. It arrived today and within the hour I had the mainspring and barrel out if it and into original movement. I already had old parts cleaned and inspected from when they blew up and I wanted to see if I could get automatic part back together properly. It was the easiest rebuild I have ever done. Wheels just seemed to jump into place. Have it all back in case and it is keeping perfect time for the past three hours. It went back together so quickly I didn't get any pictures except for some on my phone of the jump hour mechanism.
This jump hour is different from the Vulcain by how the hour disc is controlled. This hour disc is much like a date ring with a spring loaded lever keeping it held in place. On the hour wheel itself is a long spring bar that is attached to the hour disc. As the hour wheel moves this spring bar flexes and after an hour it has no choice but to move the hour disc. When you are putting the discs back you have to make the hour jump then put on the minute wheel set to 0 next to the proper hour. Might have to fine tune a bit but it's pretty easy. Just rotate dials around and see when hour moves and then readjust minute wheel if needed. One thing you have to be aware of is minute disc holds hour disc in place so if minute wheel isn't down far enough hour wheel will rise up, disengage and stop moving. Yes it happened to me. I was patiently waiting for hour disc to makes its first jump on its own and minute wheel kept on going past the hour and nothing happened. Took off second and minute discs and saw hour wheel has raised up to the point it was no longer being driven. Put it back in place and put minute wheel on a bit lower on pinion and so far so good.
This one was almost too easy. Now I have to think up another project.
Charles