I have quite a few incomplete movements that I've built up over the few years in the hobby that I use for spare parts. Many of them have a complete balance on them as well as some stray hairsprings. I've checked some of the loose springs for thickness and width and although from different movements, some of them have the exact same measurements. My question is if I remove a hairspring from a 18k beat movement, can it be used in a movement with the same 18k beat if the thickness, length and width are identical?
Very unlikely...probably better odds of winning the lottery. Balance springs will need to be vibrated to the balance. Not really a DIY job.
I used to do that with pocket watches back in the 1990s. I was mostly interested that they ran, not that they kept time. This reminds me of one of my Grail objects. One of my friends offered to teach me watchmaking, when I was between Apple Contracts. (I wanted to go to the Swiss school, there was also a program in San Francisco, but it was winding down.) He had one of these balance timing tools. On one of the horological trips, a member found one at a flea market, and he wanted to flip it, and would not sell it to me as I knew what he paid for it. I wanted it to use and not look pretty on the shelf. (which Ironically it has done for the last 18 years or so.) Took a while but one showed up at the NAWCC mart. Back in the day a watchmaker was expected to be able to turn a staff or vibrate a hairspring. This can also be done on a reference watch. The tip of the staff clicks against the glass. One has to have super powers of observation to count and do math in the head. I am not too good at the later. George Daniels or even Henry Freid would encourage one to learn how to such things themselves. The latter wrote books on the subject for the New York school district. George's book is a bit more unorthodox as he was emulating Breguet. Both thought they were preserving skills that were in danger of becoming lost and forgotten. George would ask me when I was going to make a watch, and Henry when I was going to make a model of a turbilion. Ol John Harrison could make a hairspring in his fireplace, so it can not be too difficult. This was in the 18th century. He was a bit of an metallurgist, and did a lot by trial and error. His nemesis Maskelene did take down note, as did King George III (some said this was part of his madness.) Maskelene was a theorist and valued education over experience. Anyway the iron is drawn through a draw plate. This is a common jewlers tool and was known to the Egyptians. Three springs are wound together, which is how the spacing is done. Then the whole thing needs to be heat treated in an air tight box. (The You Tuber click spring shows this in the Antikeythera re-construction using an Altoids tin) Bits of leather are scorched to make a sort of coke. Sometimes clay is used. Tempering is done over an alcohol (sootless) flame. Personally I think it would be easier for future hobbyist to make a hairspring, than it would be for them to make an engine turned case. Or even match a bezel on a hunter case. On the other hand I have been looking through my old issues of d'Horologerie et de Bijouterie. (Some are the English edition.) The watches collected use a special alloy called Nirvoloex[sp] which is anti magnetic stainless steel. So without access to the sort of ovens found in a chip foundry, It is probably not a kitchen stove project. The real answer to the question, is that one will not really know till one gives it a try and see what happens. -j