cal. 321 dials/movements and cal. 861 dials/movements swap question…

Posts
7,123
Likes
23,118
Are Speedmaster cal. 321 dials/hands/movements as an intact unit swappable with a cal. 861 Speedmaster case, and vice versa? Assuming the stems stay with the movements?
 
Posts
1,134
Likes
1,690
Generally yes, but there are slight variations from case to case, so sometimes slight adjustments are necessary.
 
Posts
7,123
Likes
23,118
Generally yes, but there are slight variations from case to case, so sometimes slight adjustments are necessary.

Thanks. Do you have a sense of where those adjustments tend to need tweaking when they occur - the case, dial, movement, etc.?
 
Posts
1,134
Likes
1,690
Thanks. Do you have a sense of where those adjustments tend to need tweaking when they occur - the case, dial, movement, etc.?

It depends- what's the situation you're in?
Usually it's the case that has the most issues (case includes pushers, dust cover, caseback). Then the hands, then dial no issues aside from caliber feet differences, then the movement (movement ring sometimes has issues)
 
Posts
7,123
Likes
23,118
I’m thinking of retrofitting a cal 863 or 861 into a 105.003 case.
 
Posts
1,134
Likes
1,690
That works, I've done it for a friend. If you recall, I was able to fit the 105.003 case to a Speedy tuesday 1 before, so there's that.
 
Posts
7,123
Likes
23,118
That works, I've done it for a friend. If you recall, I was able to fit the 105.003 case to a Speedy tuesday 1 before, so there's that.

Excellent. Do you recall if it fit right in without much adjusting, and did the stem need tweaking to accommodate any case dimension differences?
 
Posts
1,134
Likes
1,690
No, the stem was fine but a 861 crown couldn't be used because it didn't fit the crown tube of the 321 case.
 
Posts
7,123
Likes
23,118
No, the stem was fine but a 861 crown couldn't be used because it didn't fit the crown tube of the 321 case.

Thanks again. Might be getting above my pay grade, but here goes: so the existing stem from the 861 needed no length adjustments, and the crown for the 321 mated without issue to the external threads on the 861 stem?
 
Posts
1,134
Likes
1,690
I simply reused the crown and stem assembly, so I am not sure about combining the 321 crown to 861 stem. But I think the stem issue is really trivial compared to the other things you might run into, like pushers being too long for the movement to fit, or dust cover too high for caseback to fit. (I ran into these issues recently)
 
Posts
7,123
Likes
23,118
I simply reused the crown and stem assembly, so I am not sure about combining the 321 crown to 861 stem. But I think the stem issue is really trivial compared to the other things you might run into, like pushers being too long for the movement to fit, or dust cover too high for caseback to fit. (I ran into these issues recently)

Thanks, this has been really helpful.
 
Posts
522
Likes
679
Reviving this thread to ask a similar question: I'm thinking about putting a vintage 321 movement into my Speedmaster '57 Trilogy (I have my reasons), so I'm wondering if anyone has tried something similar (or into a FOIS) and might have an educated guess as to which components of the Speedmaster 57 trilogy might need to be substituted out upon putting the 321 movement into the '57 case?

I'm particularly curious about the crown/tube/stem or pushers, since based on my preliminary research and tinkering (the 321 measures 27mm x 6.74mm, and the 1861 measures 27mm x 6.87mm), I'm pretty sure the 321 will fit the '57 movement holder ring and dust cover/caseback). (I would be keeping the dial and hands of the '57). Cheers,
 
Posts
1,384
Likes
6,121
Sounds like a rather bold project to me!

I would be keeping the dial and hands of the '57

Whilst I cannot answer your initial question, I suspect marrying the ‘57 dial to a 321 movement won’t work without rather mayor intervention. The dial feet positions of a 321 differ from those of the 861 / 1861.
 
Posts
522
Likes
679
Sounds like a rather bold project to me!
Whilst I cannot answer your initial question, I suspect marrying the ‘57 dial to a 321 movement won’t work without rather mayor intervention. The dial feet positions of a 321 differ from those of the 861 / 1861.
Oh if that's the case then that might present a problem! But weren't 145.012 dials used in 145.022-68s (the former of which were of course married to 321s, whereas the latter, to 861s)?
 
Posts
5,575
Likes
9,386
Dial feet position should be fine. But the thickness of the 861 dial feet is different to the 321 dial feet. Needs adapting ...
 
Posts
522
Likes
679
Dial feet position should be fine. But the thickness of the 861 dial feet is different to the 321 dial feet. Needs adapting ...
So does that mean that Omega had to adapt the existing dials before using them on 145.022-68s? And will they be thicker or thinner on the '57 dial (1861)?
 
Posts
1,647
Likes
5,217
Dial feet position should be fine. But the thickness of the 861 dial feet is different to the 321 dial feet. Needs adapting ...
The thickness and the length.
The dial feet of the 321 are longer and slightly thicker than the 861.
While it is easier to shorten the dial feet from a 321 dial to fit the 861 movement, i would think twice before doing so.
 
Posts
522
Likes
679
The thickness and the length.
The dial feet of the 321 are longer and slightly thicker than the 861.
While it is easier to shorten the dial feet from a 321 dial to fit the 861 movement, i would think twice before doing so.
Are dial dots a reasonable option for mating an 861 dial to a 321? Or would you recommend finding a watchmaker with the necessary skills to solder new feet?