Hamilton 940- staff

[randy]

I have one with a double roller, motor barrel. Can’t tell if the hub is blue or grey.
These weren’t friction fit staffs were they ??

[david pierce]

Randy,
The Hamilton Friction Staff should have a groove cut into the shaft on the roller end to identify it.
david

[chris mabbott]

Morgen herr Randolf

What is the s/n model and year bud?
On my 940s, they are DB & SB types, none have a friction staff, they all have the staked in type.

Randy can you clarify blue or grey please? If you mean a finished factory replacement staff as grey type, it should be that one.

My pc has been down since November so I don’t have access to my files but I found an old email for my 940 DB staff replacement. It showed in the swigart book as a #126 DB staff but that was for my model. It may give you a hopping off point and you could check over at dashto.

Come on back to me big fella..

[randy]

Thanks David and Chris,
it’s a 1910 watch Chris, and the hefty hub on it almost looks like a “worn” blue which made me this of those on Walthams.
I’ll pull the roller off and look for the groove and/ or a rivet.

And Viel Danke for the listing Chris…I think I saw that also.
Looks like Tom has a few of these,..I’lll check the dimensions and order as needed.

Thanks again guys,

Randy

[chris mabbott]

Just a couple of thoughts Randy….

My 940’s range from model 1 – 1900 – 1917. They all have the staked, riveted type staffs. They were all factory finished nice shiny ones but saying that, I’ve seen a few ( None Hamilton) with a touch of blue color, that I THINK, or surmise, was a result of someone replacing a roller jewel while the roller was still mounted on the balance. So the heat travelled to the hub, and In all those cases, the roller jewel had an unsightly blob of pigeon poop in shellac form 😆

The other thing could be that someone fabricated a new staff?

100% of the factory Hammy staffs I’ve had we’re all nicely finished, no blue.. Possibly a shadow of rust.

[randy]

Thanks Chris
I just got it apart..it’s riveted.
I think you’re right about the coloring…..

Off to Dashto to order now that I have all the staff dimensions.
It’s short by .2mm. Should be 5.82 , but reads 5.80.just enough for it to hit the jewel in the dial up position…dropped the amplitude to probably 120.
Reads 250+ face down !!!!!

On another note. the JA201 mainspring that’s supposed to work for these ( as the JA203 isn’t available in anything other than an old blue spring ), doesn’t have a long enough “T” to extend enough to engage the upper slot on the barrel cover. It fits otherwise, but makes me nervous as it’s not supported on both ends.

The JA201 is 2.85 x 210 x 21.25
I have a JA701 ( for a Waltham 18s ) that is 2.90 x 225 x 21.0 that has a wider “T” that would fit much better.
The width will sit in the barrel with no interference.
I’m not sure that the strength would be that much out of bed to give it a try.

Have you had a similar experience ??
R

[chris mabbott]

I can’t remember if it was with the 940’s or not but it seems that I always have to fiddle with the odd one, even with the factory cross referenced number. And like you, I’ve found Waltham springs can get you out of a bind. Even if they’re a bit thicker, it shouldn’t matter too much.

There’s a guy on the bay who sells the new alloy springs made to spec of originals, but I’ve always had to mod his springs.
One that comes to mind were the three Elgin convertibles that I did recently, they have the ….. Little round tab on the barrel wall, can’t think of the technical term, anyway, his springs, crossed to the Elgin number, but they don’t have round holes, rather D shaped, so I had to round them out to fit.. A small detail but still, his springs seem to work well.

Anyway, glad you got her sorted old chap

[randy]

I’ll look again on Ebay for the guy you are talking about.
I thought I remembered someone selling the new alloyed versions, but I couldn’t find him during my search.
If I can’t I’m going to load the Waltham version and see how it runs.

Yea,..I think that more and more we might be facing this dilemma.

Thanks Chris…be well !

Randy

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