OK OK so straightening is the wrong term.
And I am sure most of you will say don't!!!!
But I am commited to try to correctly form a mangled hairspring. I can not make it any worse (???)
It is a Brequet I have started on.
Besides trial and MUCH error can anybody make a few SIMPLE suggestions.
Mel

Mel, a picture is worth discussing. i.e. the spring below is essentially non-workable. (for me at least!) I had to find a replacement. (not easy!)

The best advice is to be very patient and have a definite plan of action before attempting work on the hairspring.Bench Practices for Watch and Clockmakers by Henry B. Fried has an excellent section on straightening hairsprings of course finding someone close by you who has the skills than can be taught to you is the best way to learn as an apprentice would have. Straightening hairsprings is one of my favorite pastimes good luck to you.......

Regards, John

I live in Plymouuth MA., and would love a pro. whose's shoulder I could look over.
Found this on the net. I was thinking of scaling down to my size and putting my spring over it and using as a template. I have to know if this is the correct shape for a 16s elgin.
Where does (should) the overcoil leave the plane of the main spring.

Melvin, that pic looks like it may have come the textbook John mentioned. You can probably find it Online.

Hi Gary and John,
Yes it did come from the internet TM 9-1575.
I have found it quite instructive. But I am not sure the shape that comes accross the coils is correct. Also I thought that the S/F pins are in the wrong place.
Where does the hsprg change level to become Brequet?
All help is accepted.

Mel, I have two good sources of Hairspring straightening. The first, from the Bulova watchmaking school presumed you had about 1,000 springs to practice on. A good idea, but less practical today. The second is from the Chicago school of watchmaking who in this lesson spent a lot of time explaining how Hairsprings were made, and how they replaced gravity for creating the "pendulum effect", then they showed how to straighten coil errors;

and bent Hairsprings (below). The idea of fixing the three dimensional Breguet hairspring bends is honorable indeed, maybe Chris can pipe in with a primer on that . . . .

Here are a couple pages from the Fried book that John mentions that may answer your question. I would highly recommend this book if you are going to work on hairsprings.

Fried's book is a trusted resource at my bench. DeCarle takes a close second. anything other than minor hairspring adjustment is out of my league.

I do suggest you practice on something you don't care about first

Hi Dave,
I have been keeping quiet, as I cant saying anything really helpful, hairsprings are one the most difficult areas and its all about practice many many hours, the theory in the book make is look simple putting into practice is a different matter some people can figure them out others will never, the hairspring has to be perfect or the watch wont time out, therein lies the problem there is no close enough it has to be right. The only useful thing I can say is not to even start to correct an error until you are 100% sure where the correction needs to be people take a guess where the bend should be then loose the point to reverse the put another erroneous bend in to compensate for the first two, then add another and so on, you need to sit and with a good strong loupe really study where you think the error is, maybe gently tease the coil to see the effects without committing to a correction, often its just one tiny adjustment needed a couple of seconds to do five minutes to spot. Making overcoils is quite easy and fun, that is area you constantly have to repair as people tear the balance cock out and stretch the coils, bounce the balance around on soft hairsprings or stab at the regulator pin to release a tight springs.

Great, I know what I will be doing over the next weeks, pulling the few hairs out of my head!
A grateful Mel

Hi All,
Got it close using tweezers and pin technique. Better than two tweezers.
Then tried for more, kink!!
Need a break for a while.
Maybe a day....
Mel

I noticed that when Dave replaced the balance in my Rail Road King, he kept the original hair spring rather than the hair spring that was on the donor balance wheel.

I understand the gratification that comes from saving a compromised spring, but at some point, might a fellow be farther ahead using a spring from a donor watch?

I am all ears on this topic. I'm on the fence about tooling up and coming in whole hog.

Nice work Mel, quite impressive to even attempt a hair spring repair from my fledgling perspective.

Mel, using Davids posted (2) photo, I have repaired a few springs such as pictured by freeing the collet and stud so you have just the collet, stud and HS in your hand. Then I stick a round toothpick in my bench anvil and lightly press the collet onto the toothpick. This works better than the sharpened, pointed rod made for holding balance bridges. The wood gives a little more friction in the collet and a little Rodico can help hold it. You are going to try to turn the spring inside out as long as it is not kinked anywhere. Place the collet over the tooth pick and push the large coil (Stud end) down over the collet to the bottom of the tooth pick. If it bottoms out to soon (Before it stretches) then use a longer piece of sharpened peg wood. You'll need three hands at times and a lot of luck and patience. I have had some success with this but not always. It's kind of a last resort. I have also used it on Mainsprings with a lot of luck. The HS will never be right again but may work well enough to get decent time out of the unit for showcasing . If you intend to sell it I would let the buyer know the HS should be replaced, I'm on a gray line here as I have a policy of If you can't do it right, don't do it at all.

This information is the main reason I subscribe to this site. There is SO MUCH good, no great ,information you guys share with (us) neophytes. Thanks again.
Mel

Hi All,
I have been back to hairspring straighting. I tried just untangling some hairsprings. And had modest success. Looking for more candidates. So if anybody has old mangled hairsprings they would ordinaryly throww out, because they r too short because of breakage (or some other calamity). I am willing to accept and am willing to pay a small fee. (0-$)
Please DO NOT EXPECT THEM BACK..
Thanks to all Mel

Mel, I won't expect them back and I think I can find a few basket cases for you. No charge. I'll look in the AM to see what I have.