Internet Horology Club 185
Late 19th Century Elgin Fusee
March 15, 2008, 19:19David Abbe
Late 19th Century Elgin Fusee
This is a humdinger! The Elgin geniuses who created their manufacturing machinery also designed and built a Fusee-Based Dial Indicator complete with stand!
March 15, 2008, 19:25David Abbe
So I get it apart, and it uses a 4-1/4" long Fusee Chain, that is wound around a shaft with the pointer on the dial. The same shaft also has an extra-long 12 size mainspring wound the other way to give some tension to the Fusee which is strung up and over a pulley on the moving gauge point and back down to a fixed "hooking bar" that has a very clever vertical adjust so that the operator may "zero" the dial on a reference part for measuring manufacturing tolerances. All done in the 19th century, albeit late 19th, but certainly a long time before some other gauge companies made a business oput of precision QC products!
March 15, 2008, 19:28David Abbe
So I have in pieces a 0.001" graduated dial indicator with 3 moving parts and about 1/4 inch of travel! Overall accuracy would be pretty good, but most important this is clearly a comparator gauge, and would be well within the "10% rule" when used to measure tolerances rather than absolute size! Tha simplicity is fantastic. Had the old imperial Japanese figured this kind of thinking, they might have been knocking on our doors sooner than late 1941!.
March 15, 2008, 19:30David Abbe
So do I oil the chain with watch oil while reassembling this? The Fusee chain has "micro-hooks attached to both ends, is there a "trick" to re-hooking the Fusee chain?
March 15, 2008, 19:51Tom Brown
The way I clean the chain is I put a piece of pegwood in a vice, you wrap the chain around once & you apply a little oil where the chain goes around the pegwood. You then work the chain back & forth until is moves freely.
Next I rinse the chain in hairspring cleaner & then let it dry. Then to make sure there is nothing sticking to any link in the chain you run the chain quickly over a flame to burn off any hairs etc. that might be attached.
To attach the chain you will notice there are two different hooks, the hook with the extra barb hooks on the barrel & the other (plain hook) in a watch would attach to the fusee.
As to how to attach this all together since it isn't on a watch I am not sure how it is hooked up or wound.
Hope any of this helps.
March 15, 2008, 21:58David Abbe
Tom, I got it allmost to the final point with the mainspring preloaded, and the hook in the mainshaft, over the pulley and into the anchor, and noticed there was one link that was odd. . . Poof, it broke.
The rest of the chain looks fine, but now its in 2 pieces. Know anybody who can fix these?
March 15, 2008, 22:23Tom Brown
One time talking to Chris Abell he mentioned he had just finished repairing one for some one. Was the chain total length 4 1/4? I can see if I have one that size.
May 03, 2008, 14:25David Abbe
Hi Tom, Yes the Chain is 4 - 1/4 inches long, although that is not too critical as this is a winch application and it is less limited by chain length deviations.