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This 16mm Eastman Color film was produced by the Bureau of Audio Visual Instruction and the Office Of Career Education of the Board of Education, City of New York in 1974 and features a tutorial on various methods of correcting damaged hair springs in watches and clocks, as demonstrated by horologist Henry B. Fried. This reel was transferred from my own 16mm archive print using my Eiki Telecine. The Eiki projects a 24fps print at 30 frames per second for a flickerless NTSC transfer. A special diffusion plate eliminates the 'hot spot' of the projector, and the sound is pulled right from the optical track.
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By Fran

17 thoughts on “Hair spring straightening 1974”
  1. Avataaar/Circle Created with python_avatars Patrick Lozito says:

    3 years after this film was made, I was an apprentice at a world famous gunsmith shop right in New York City. People
    of the same wonderful character as Mr. Fried were the essence of New York City industry. It was and is an honor to be taught by
    and learn from people such as this. I will never forget those that taught me. Thanks Fran for this wonderful episode.

  2. Avataaar/Circle Created with python_avatars Gherghinescu George says:

    Thank you so much Fran! This stuff is gold! I've been a watchmaker for over a decade now and hairspring work is some of the toughest to get right. Modern swiss hairsprings are harder to bend accidentally than ones in older watches. The modern alloys have better elastic propreties and take more bending forces before they deform plastically. Also they are usually thicker as modern watches tic faster so usually need stiffer springs than older ones. They also get heat treated differently along the lenght of the ribbon like wire, more elasticity in some parts and more rigidity in other as it is needed.. sometimes you can see that as a yellower colour at the very exterior last part. The Hairspring has a major role in the precision of the watch because it is part of the mechanical oscillator assembly that determins timing. That assembly (Balance wheel and hairspring) is carefully balanced in it's static (rest position sort of) and sometimes dynamically too so if the hairspring gets bent it changes the center of mass of the entire assembly. Then all the work that goes in a quality watch is negated and the watch will have worse performance in different positions. For example a high grade watch of excelent precision like a chronometer if during a routine servicing has it's hairspring even slightly mistreated will no longer pass the chronometer certification tests and it will take a top watchmaker hours to get it back close to original spec. Latest technology in hairsprings tho makes adjusting them not possible and not needed anymore, they are made from silicium through a fotolitography technology not too different from chip manufacturing. They make perfect mathematical shapes every single time, varyable thickness to control elasticity locally and spiral geometry. They provide performance theoretically not possible with steel alloys, close to an ideal hairspring. Magnetization is not a problem anymore, bending is completely elastic until it brakes so goodbye deformation and chronometers meet specs after a watchmaker gets inside.. usually hehe. Longest post ever :)))

  3. Avataaar/Circle Created with python_avatars Ken Hukushi says:

    it's 1974, Quartz watches are hitting the market, Hair Spring Straightening would be completely useless very soon.

  4. Avataaar/Circle Created with python_avatars musicmakelightning says:

    In all my years of amateur pocket watch and clock repair, I have never successfully fixed a bent hairspring. Thanks so much for posting this.

  5. Avataaar/Circle Created with python_avatars Benjamin Maggi says:

    I've been watching this random series of videos with quite the enthusiasm, first of all o love the intro, amazing job Fran, second and more importantly I love the content you've picked for us, it's random but it has that nostalgia around it that I cannot resist! thank you !

  6. Avataaar/Circle Created with python_avatars Slightly Nasty says:

    I've had to manually manipulate a wristwatch hairspring once, there's nothing quite like feeling a sneeze coming on and trying to rapidly extricate your tweezers before the apocalypse hits.

  7. Avataaar/Circle Created with python_avatars Donald Rivers says:

    I got into a watch repair rabbit hole last year, on youtube and watching people doing watch repairs on twitch. I never saw this information though. I saw that there can be a problem if the hair spring becomes magnetized (it will run fast because it sticks to itself) and you have to demagnetize it.

  8. Avataaar/Circle Created with python_avatars rene0 says:

    Anyone else has Pink Floyd flashing in their brain at the intro, getting mildly disturbed that some dude starts talking instead of song playing, deciding to queue this for later and searching youtube for the Floyd song?

  9. Avataaar/Circle Created with python_avatars Johannes de Sloper says:

    Cool..recently I had one jumping out of a starter of a 2 stroken generator… woah..gaven me serious trouble and grease all over to get it back.

  10. Avataaar/Circle Created with python_avatars Cliff Hartle says:

    Wow I never thought it was hair spring unentrangling. I would have thought the main practical problem would have been escapement adjustment.

    The more you know. 😉

  11. Avataaar/Circle Created with python_avatars Jeffrey Shier says:

    If YouTube would have been around when I was growing up, in the 60s and 70s, I would have been a lot smarter today.😉

  12. Avataaar/Circle Created with python_avatars circuit blog says:

    One of the best video ever this take me back when i repair spring loaded clocks
    I did the same thing in fixing springs
    Thanks fran for posting

  13. Avataaar/Circle Created with python_avatars Sean Batiz says:

    Fran, as myself being a lifelong tinkerer of a great many mechanical, electrical, hydraulic items, ranging from the most minute of parts within an antique pocket or wrist watches movements/complications, up too having replaced countless rivets of an antique steam traction engine, I can assuredly state that I could’ve very much used such valuable skill knowledge some 3 decades ago! Great film! On the topic of transferring these vintage films, I have slowly collected over the course of 2 decades, a very extensive “library” of ‘original’ literature for my two 1955 Buick Super’s, including a set of original 35mm “Slidefilm” spools with their adjoining ‘vinyl’ audio tracks for each which were instructional aids for salesmen, technicians &, general info for potential “prospects” (customers). I’ve acquired an original mid-1950’s “DuKane” Slidefilm Projector w/builtin Turntable that I restored fully for sampling these. Ten of the 30 of these use the somewhat rare 16 inch diameter “transcription” vinyl records that are just MASSIVE by comparison; that DuKane Projector plays this size with zero problems… anyways, have you any pointers of the best “simple” method I can employ for digitizing these film strips, for archival posterity, before they’re fully destroyed from the acetate breakdown process? These date from 1952 thru 1955 & several of which are already gassing off strong vinegar odors when metal canisters are opened, especially those which are in color. Any advice will be greatly appreciated & TAKE CARE! You’re a true YouTuber GEM!

  14. Avataaar/Circle Created with python_avatars 1978ajax says:

    Thanks Fran; have one which few repairers will even touch these days – so now willing to try it myself. You may have saved my watch!

  15. Avataaar/Circle Created with python_avatars Alan Canon says:

    Been loving the audio quality of these transfers, reminds me of the old Bell and Howell 16mm school projectors booming away in the classrooms of my childhood, except no projector noise! [edit: googling it, looks like those soundtracks could do 100 Hz up to 5-6 kHz., flat within 6 dB with 30-50dB SNR (limited by maximum contrast of the photographic film, for variable density process). So better than telephony/AM's 300-3000 Hz straightjacket, to be sure.]

  16. Avataaar/Circle Created with python_avatars Electrons Needed says:

    this has been very useful i have a travel clock with a damaged hairspring might be able to fix it now 🙂 ( i also no im an imposter but your playlist showed the unlisted video )

  17. Avataaar/Circle Created with python_avatars Matt Wietlispach says:

    Wow! I didn't know those springs were called "hair springs." I've fought those for years. This same type of coiled spring is used in meter movements in all kinds of aircraft instruments. The "hair spring" holds the needle down and coils around the core and the outer magnet around it. Introducing a small voltage moves the needle against the pull of the "hair spring" to the desired position. This meter movement is extremely effective and works with light weight needles, pointers or warning flags. Naturally, moving something larger and heavier, like a compass card attitude sphere in a large indicator, have to rely on servo loops where gear trains and motor drivers nulled by synchro or potentiometer feedback are required. This "hair spring" is easy to see on most analog consumer electronics meters, like VU meters. Just look at the where the needle is attached and you can see the core coil and "hair spring". It is very uncommon to salvage these springs since they are much thinner than the clock spring examples the clocksmith demonstrated. Sometimes using a fine-tip dental pick can untangle a spring, but the meter movement is not made to take apart and is normally exchanged with a replacement. Sometimes the meter movement has to move a larger pointer that has a super-fragile shaft leading to the pointer. In these cases, they actually have counterweights on the rear of the movement to balance the weight on the front. Since I can't really salvage most meter movements in avionics, I simply have several of the same model indicator to cannibalize to fix another. In the "real world" of aircraft instrument repair, they would use a brand new meter movement that no doubt would have a lead-time of months and an astronomical cost for the part and the repair. But at least I finally know what that coiled spring was called. I WISH the ones I have to deal with were as big as his. Thanks Fran, I learned what a "hair spring" is called after fighting them for years.

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