My favorite Illinois - Bunn 17j

[Fred Hansen]

The Bunn and Bunn Special typically have 6 position markings from the low 1.7 million serial numbers on.

Sometimes less commonly the 6 position markings show up on Bunn Special movements at lower serial numbers and I've seen these as low as marked movements in the 1.2 millions. But I believe these low serial number marked
movements were likely finished later than others from their same serial ranges.

Fred

p.s. Great watch Larry!

[Robert Sweet]

Originally Posted by Fred Hansen

The Bunn and Bunn Special typically have 6 position markings from the low 1.7 million serial numbers on.

Sometimes less commonly the 6 position markings show up on Bunn Special movements at lower serial numbers and I've seen these as low as marked movements in the 1.2 millions. But I believe these low serial number marked
movements were likely finished later than others from their same serial ranges.

Fred

p.s. Great watch Larry!

Fred,

Thank you.

Robert

[John Cote]

Originally Posted by Fred Hansen

The Bunn and Bunn Special typically have 6 position markings from the low 1.7 million serial numbers on.

Freddy,

I am going to have to argue with you a bit here. Concerning the 17j Bunns, although I am sure some suggestions exist, I think the company made a decision around the end of 1904 to begin to mark these Bunns as "Adjusted to 6" instead of "5 Positions". I think that near the end of 1905 or early 1906 they quit doing this and went back to marking them "5 Positions".



Here is a pretty late one that is marked 5. I have other photos of movements after 1905 that are marked 5. I have always thought that the movements were probably really adjusted to 6 but that for marketing purposes they went back to the 5 marking to differentiate them from the Bunn Specials.

[Larry Treiman]

Why would Illinois have bothered adjusting the Bunn grade watches to the sixth position (6-up) if all they were claiming was five positions? It has always been my understanding that adjusting to the sixth position required some compromises in tolerances. Has anyone turned up any Illinois factory documentation on actual adjustment tolerances?

A Hamilton comparison might serve to illustrate this point. Adjustment standards for the grade 950 (which was adjusted to five positions), in notes taken from a 1926 Hamilton factory letter, show that the 950 was allowed a maximum variation in all five positions of 10 seconds. By comparison, for the 950B (adjusted to six positions), Hamilton allowed a maximum variation of 10 seconds per day between dial-up, dial-down, and 12-up. Add in 9-up and 3-up (for the same basic five positions as the 950) and the tolerance became 13 seconds. Throw the sixth position (6-up) into the mix, and the maximum variation permitted between all six positions for the 950B jumped to 20 seconds/day! Draw your own conclusions.

Larry Treiman