It's a hacking movement

[GPrideaux]

I've made a mistake that makes me feel very foolish. I'm sharing it here so other beginners might learn from my mistake.

A couple of months ago I started working on a Seiko 6105 from 1975, the movement from a classic "Captain Willard" watch belonging to a colleague. The watch had its challenges and there were lots of things I was getting help with from more experienced people in these forums. I was at the point of reassembling the movement for the first time. The movement was running when I turned it dial up in the movement holder to fit the calendar works. All ok, check that the date advances as expected, then turn it over again to find the watch had stopped. Not only that, but the balance would now not swing at all. Not usually a pessimist, I nevertheless assumed the worst: I've caught the balance with the movement holder and broken the balance staff. I felt sick: this is no practice movement, it's a colleague's watch, and a classic, too. Mentally beating myself up, I immediately checked on eBay for NOS replacement balance complete, found one, and bought it. Later, I think it was the next day, or possibly a couple of days later I psyched myself up to go back to the watch, took the balance out and was surprised to find it apparently intact. Did I damage a bearing? Inspection follows: all looks ok. Reinstall the balance, it now swings freely! Much work followed addressing a few different issues with the watch but nothing that would explain why the balance went from swinging freely to not swinging at all. It remained a puzzle. Until a week or so ago when I was finally happy with the watch and reassembled it for the last time. I gave it a wind, dial and hands on, into the lightly restored case, set the time and date to the second, using what Seiko calls the seconds setting lever but is commonly called the hack, and strapped it to my wrist to give it a test run for a couple of days. Even then I didn't twig straight away.

Yes, the Seiko 6105 is a hacking movement, the first one I've worked on. When you pull the crown out to position 3, a "seconds setting lever" in the movement moves in response to rest against the fourth wheel, acting as a brake and stopping the movement until the crown is pushed in. When I had set the calendar works I had, naturally, pulled the crown to position 3 to check that the date wheel advanced as it should ... then wondered why the movement had stopped.

In the end it worked out for the best. I think I had been about to accept the watch as it was, not realising that the balance was actually touching the pallet bridge for part of its movement, and I also needed to polish out a divot in a jewel and adjust the side and end shake on the barrel arbor, none of which would have got the attention they needed if I hadn't been trying to track down what ended up being not a bug, but a feature.

Now, can I interest anyone in a NOS balance for a Seiko 6105? (Just kidding: we don't do the buying and selling thing here.)

[oldhippy]

I'm sorry to say you have learned the hard way my friend. When it comes to working on the dial side always remove the movement from its holder/vice. Another tip when you have removed the balance complete keep it out of the way and cover it. 

[Neverenoughwatches]

3 hours ago, GPrideaux said:

I've made a mistake that makes me feel very foolish. I'm sharing it here so other beginners might learn from my mistake.

A couple of months ago I started working on a Seiko 6105 from 1975, the movement from a classic "Captain Willard" watch belonging to a colleague. The watch had its challenges and there were lots of things I was getting help with from more experienced people in these forums. I was at the point of reassembling the movement for the first time. The movement was running when I turned it dial up in the movement holder to fit the calendar works. All ok, check that the date advances as expected, then turn it over again to find the watch had stopped. Not only that, but the balance would now not swing at all. Not usually a pessimist, I nevertheless assumed the worst: I've caught the balance with the movement holder and broken the balance staff. I felt sick: this is no practice movement, it's a colleague's watch, and a classic, too. Mentally beating myself up, I immediately checked on eBay for NOS replacement balance complete, found one, and bought it. Later, I think it was the next day, or possibly a couple of days later I psyched myself up to go back to the watch, took the balance out and was surprised to find it apparently intact. Did I damage a bearing? Inspection follows: all looks ok. Reinstall the balance, it now swings freely! Much work followed addressing a few different issues with the watch but nothing that would explain why the balance went from swinging freely to not swinging at all. It remained a puzzle. Until a week or so ago when I was finally happy with the watch and reassembled it for the last time. I gave it a wind, dial and hands on, into the lightly restored case, set the time and date to the second, using what Seiko calls the seconds setting lever but is commonly called the hack, and strapped it to my wrist to give it a test run for a couple of days. Even then I didn't twig straight away.

Yes, the Seiko 6105 is a hacking movement, the first one I've worked on. When you pull the crown out to position 3, a "seconds setting lever" in the movement moves in response to rest against the fourth wheel, acting as a brake and stopping the movement until the crown is pushed in. When I had set the calendar works I had, naturally, pulled the crown to position 3 to check that the date wheel advanced as it should ... then wondered why the movement had stopped.

In the end it worked out for the best. I think I had been about to accept the watch as it was, not realising that the balance was actually touching the pallet bridge for part of its movement, and I also needed to polish out a divot in a jewel and adjust the side and end shake on the barrel arbor, none of which would have got the attention they needed if I hadn't been trying to track down what ended up being not a bug, but a feature.

Now, can I interest anyone in a NOS balance for a Seiko 6105? (Just kidding: we don't do the buying and selling thing here.)

Been there lol, happy to say not for a long time

[GPrideaux]

I have to say that I nearly didn't post this: I felt embarrassed to have made such a blunder. But this forum is so supportive it felt safe to share, and it might save someone else from making the same dumb mistake. And if others have a chuckle at my expense ... I'll survive.

[mikepilk]

We have all made silly mistakes (and still do ). It's how we learn.