Valjoux 72 stops running when crown is screwed down?

[slay]

I have a little issue with a Vj72 build: every time I screw down the crown, the movement stops sporadically. As if it doesn't like when there is just a little bit of pressure on the stem from the crown.

Any idea how I can fix this? The stem is already cut as short as possible, if I cut it even shorter, I won't be able to set the watch.

Even when I screw the crown in just half way, the movement stops sporadically. If I just screw it down about 1/3, it keeps running.

[Revere]

I have a little issue with a Vj72 build: every time I screw down the crown, the movement stops sporadically. As if it doesn't like when there is just a little bit of pressure on the stem from the crown.

 

Any idea how I can fix this? The stem is already cut as short as possible, if I cut it even shorter, I won't be able to set the watch.

 

Even when I screw the crown in just half way, the movement stops sporadically. If I just screw it down about 1/3, it keeps running.

Is the stem perfectly concentric with the crown tube? That is to say, is the slot in the movement for the stem perfectly in line with the middle of the crown tube? I'm not sure what the physical consequences were but I had a similar issue once when I was assembling a watch in which the stem was crooked because the crown tube was just a hair lower in the case than the hole for the stem.

 

Other than that, do you think it is the crown being screwed itself, or could it be something else that occurs as a result of the crown being screwed? Is the act of screwing in the crown moving the movement inside the case maybe touching the balance against the inner side of the case enough to stop it? (this seems unlikely because the v72 has the balance a fair bit inset into the movement)

 

 

Edited December 24, 2015 by Revere

[slay]

My suspicion is that it's the pressure exerted on the stem from the spring loaded Rolex crown. For some reason the movement doesn't like the pressure.

Another thing I observed is that there is some resistance ever other half turn, no idea why.

Movement is aligned perfectly and doesn't move at all.

Oh also: when there is no stem at all inside the movement, it also stops sometimes!!

[SSTEEL]

Stem too long?

[ceejay]

You seem to have problem that's not directly related to the stem as you say it sometimes stops without the stem.

There are numerous reasons for the intermittent running.

Cracked Jewel, bent pinion, damaged gear etc, it could just require a service. Unfortunately, until you get it looked at you are just guessing.

Good luck

Sent from my iBend 6

[slay]

I spent some time thinking about this and remembered that I cut the old dial feet pretty close to where the keyless works is. I cut the feet, but I recall that the little dial feet's base was still on the dial and I didn't want to damage the dial trying to pry it off.

Fast forward, my suspicion was that the dial feet base was pressing onto the keyless, because it's protruding a little bit from the dial.

I took a Dremel and sanded off various high points on the dial, assembled everything back together and it seems to be running. Not sure if that fixed it, but it's most definitely running a lot better than before!

[slay]

Stopped again but I figured it out and it's FIXED!!

Two issues interacted with one another cause this:

1) there were some high spots on the bottom of the dial causing it to sit slightly higher than normal

2) the running seconds @9 Subdial hand's tube was a bit too large, requiring the hand to be pressed too far into the pin to 'stick'. This created friction with the dial (that was sitting slightly higher than normal, just a tiny bit that makes no difference normally, but in combination with 2, the Subdial hand pressed against the dial.

This is what cause the movement to stop sporadically. I have no idea why this was made worse when there was pressure on the stem, but I suspect that pressure from the sprig losed crown caused the Subdial hand to be pressed even more against the dial.

Solution was to take tweezers and make the Subdial hands tube a bit tighter. That way, I didn't have to press the hand as far onto the pin as before and now there is sufficient clearance between running seconds and the dial