What does "Adjusted' mean on a Hamilton 912?

[Poincon]

When a Hamilton movement, in this situation a 17 jewel Grade 912, says "adjusted", how may positions and/or temperatures did they adjust for. The only reference I found seems to say two (2) positions without any consideration for temperature. Thank you.

[Robert Sweet]

Poincon,
"Adjusted" on Hamilton movements indicate they are adjusted to temperature (hot and cold) only.

"Adjusted to Three Positons" would include temperature (hot and cold), isochronism, and the three positons.

Robert

[Poincon]

thank you

[Tom McIntyre]

Poincon,
"Adjusted" on Hamilton movements indicate they are adjusted to temperature (hot and cold) only.

"Adjusted to Three Positons" would include temperature (hot and cold), isochronism, and the three positons.

Robert
Without digging one out to look, I thought that all 10 and 12 size Hamiltons had a Breguet overcoil and were therefore adjusted to isochronism. My presumption was that they were also adjusted to 3 positions (dial up, dial down, pendant up). Of course, they may not have been fully rated to those positional adjustments. At the time these watches were made it would have taken an extra effort to make them not keep time to the 1890 railroad standards. i.e. the balances and hairsprings were matched during assembly to give at least 1 minute a week accuracy.

The markings meant the watch had been tested to the specifications, not that an unmarked watch did not meet them.

[Robert Sweet]

Tom,
My answer was based on the movement descriptions of the 974 and other movements such as the 924 which only list adjusted to "Temperature" and are marked "adjusted", of course some Hamilton momements don't even mention "adjusted".

If "isochronism" is assumed by Hamilton in their description and not mentioned, I stand corrected.

Robert

[Kent]

...
At the time these watches were made it would have taken an extra effort to make them not keep time to the 1890 railroad standards. i.e. the balances and hairsprings were matched during assembly to give at least 1 minute a week accuracy.
...

Tom: Since 1890s railroad standards were +/- 30 secs/week, I'm not clear what you are saying here, although I understand that the design and the manufacturing process for the No. 912 reseulted in a fairly tight rate.

[terry hall]

The 1927 catalog does not mention adjustments... but does provide features... This scan courtesy of Don Dahlberg and the NAWCC Library

http://www.eliznc.com/personal/Terry/Hamilton%20Cat%20scans/ham1927/page11and12.jpg

[terry hall]

The 28-29 seems to be the only catalog page to mention 'adjusted' and provides no details... I checked up thru about 1937....

http://www.eliznc.com/personal/Terry/Hamilton%20Cat%20scans/ham1928and29/page10.jpg

[Robert Sweet]

Below is a catalog page of the 912 from a 1924, Timekeeper.

Robert

[Poincon]

wonderful information, thank you all

[Tom McIntyre]

Tom: Since 1890s railroad standards were +/- 30 secs/week, I'm not clear what you are saying here, although I understand that the design and the manufacturing process for the No. 912 reseulted in a fairly tight rate.
That was really all I was saying Kent. By 1920 with preformed overcoils and modern materials, the watches were about as good as anything had been 30 years earlier.

There was no particular reason to mark the adjustment details on these smaller watches since they were not subject to railroad rules.

I suspect the 10 size 921 and 923 were close to, if not the equal in timekeeping of the 992b and 950b at the same time of production. Surely this information is in the Hamilton archives somewhere.

[Don Dahlberg]

The idea of adjusting standards is very complex. It is not only a question of the number of positions, but also the standards for the differences between positions, which changed with time.

I have not seen any standards for the older models, except for the 992. We do have some 1958 documents with the standards at that time.

The 992B was a 6 position watch. Before it was cased it had to be regulated between 0 and +5 seconds. The difference between dial up and down had to be less than 6 seconds. The difference between DU-DD and 12 up had to be less than 10 seconds. The difference between DU-DD, and pendant left, right and up had to be less than 15 seconds. Including the 6th position had to be within 20 seconds. So you see the standards changed over the positions. Then the watch was cased and tested for five days pendant up. The maximum variation had to be within 5 seconds and the regulator had to be within half a division from center.

The 921 was a five position watch. The standards were +/- 5 seconds, and the differences between positions were DU-DD 6 seconds, DU-DD-12up 12 seconds, DU-DD-12-3-9 up 15 seconds. So you see the total rate was relaxed a bit and the three position difference could be 12 seconds instead of 10. The two and five position standards were the same as the 992B. They did not check the 6th position.

The 917 was a three position watch. The standards were +/- 5 seconds. The differences were dial up and down 6 seconds, but dial up, down and 12 up was now up to 15 seconds.

It lists 12 sizes 17-19 jewel as one position, whatever that means. There were no positional differences listed. Just that the rate had to be within 6 seconds. So it appears in 1958 12 size watches were regulated pendant up only.

This 1958 document even listed 18 size. It gives "std" movements as one position, but says that dial up and dial down should have a difference less than 6 seconds and dial up-down and 12 up less than 15 seconds (?). Then it lists "Pos" movements, but only gives dial up and down with a difference less than 6 seconds. I am confused!

I think someone is submitting the question to the NAWCC library and I shall try to find standards for some of the older movements. I don't know if I shall find them.

In summary, not all three position standards are the same. All watches adjusted to three or more positions may not be to the same number of seconds.

Don

[Tom McIntyre]

Don, is there any documentation on what adjusting they did to correct watches that were out of specification. i.e. did they only manipulate the HS or did they flatten the end(s) of the balance staff?

They might also have adjusted the banking although I have never been able to understand what good that might do.

[Don Dahlberg]

Tom,

Gordon Mennick, who worked in the hairspringing section from 1949 to the 1970 when Hamilton stopped production, talked about one of the fellows who corrected hairsprings on watches that were defective. That person was the best of the hairspring group, because he had to identify and correct distorted hairsprings and do it quickly. Unfortunately, we lost Gordon last year and I cannot ask him your question. I have not read anything on who determined what was wrong with a defective watch. I can only assume that the watch had to be examined by someone to see were the defect occured. I know that the hairspring was often the problem, because Gordon talked about getting grief when an unusual number of the hairsprings that he had formed, had to be corrected later. Other defects would have been rare at that time. The balances were solid by then and more difficult to deform through handling. There were instruments that helped with the poising. So the hairspring was usually the problem in later years, but I do not know about the earlier years.

Don