Hair Springs

Cuckoo348

Registered User
Jun 13, 2004
175
0
16
90
Boardman, OH
Country
Region
I have two clocks in my shop that have hair springs on the balance wheel. Both have one coil over laping a coil. This causes the clock to run fast and can not be adjusted to run slower.
Can any one give me a procedure to straighten the springs?:confused:

"Doc Clock"
 

bangster

Moderator
Staff member
NAWCC Member
Jan 1, 2005
19,988
513
113
utah
Country
Region
Fixing hairsprings is no easy matter. Show us pictures. There might be a simpler solution.

bangster
 

Willie X

Registered User
Feb 9, 2008
14,357
1,602
113
Bang,

Two pair of good AA tweezers and a lot of practice. Be sure to do the 'practice' on junk parts. Out of plane coils are the most difficult to restore.

Willie X
 

Smudgy

Registered User
May 20, 2003
2,874
25
38
Country
Region
The hairsprings you have may be Breguet hairsprings (overcoil hairsprings). If they are Breguet you definitely do not want to flatten the overcoil. A breguet hairspring looks like the ones in the following links
http://en.wikipedia.org/wiki/Balance_spring
http://www.onlineclockbuilding.com/HAIRSPRING/carpenter.html
http://www.bhi.co.uk/aHints/watch.html
As a note, I am using the term Breguet hairspring generically. Breguet developed the first overcoil spring in an attempt to improve isochronism. The term Breguet is commonly applied to all overcoil hairsprings even though a Breguet spring has a very definite mathmatical formulation to the shape of the overcoil. Not all overcoil hairsprings use the same shape as defined by Breguet.

If your clock has a coil out of plane due to unintentional bending and is not overcoiled intentionally then ignore this post and feel free to flatten your spring.
 

bangster

Moderator
Staff member
NAWCC Member
Jan 1, 2005
19,988
513
113
utah
Country
Region
Until we see some pics, we can't know what to recommend. I've had some success straightening bent hairsprings. If they're beyond me, I've shipped them off to Dave LaBounty.

Brief procedure: Remove the balance, hairspring and all, from the clock. Remove the hairspring from the balance (its collet is friction-fit on the staff).
Affix it to a flat surface somehow. Go at it with two pairs of pointy tweezers and a lot of magnification.

But sometimes, an over-coil will correct itself when the balance & spring are removed from the clock.

Best (& only) source I know for info on hairspring repair is Henry Fried's Bench Practices For Watch and Clock Makers.

Pictures would help.

bangster
 

shutterbug

Moderator
Staff member
NAWCC Member
Oct 19, 2005
46,968
1,997
113
North Carolina
Country
Region
The hairsprings you have may be Breguet hairsprings (overcoil hairsprings). If they are Breguet you definitely do not want to flatten the overcoil. A breguet hairspring looks like the ones in the following links
http://en.wikipedia.org/wiki/Balance_spring
http://www.onlineclockbuilding.com/HAIRSPRING/carpenter.html
http://www.bhi.co.uk/aHints/watch.html
As a note, I am using the term Breguet hairspring generically. Breguet developed the first overcoil spring in an attempt to improve isochronism. The term Breguet is commonly applied to all overcoil hairsprings even though a Breguet spring has a very definite mathmatical formulation to the shape of the overcoil. Not all overcoil hairsprings use the same shape as defined by Breguet.

If your clock has a coil out of plane due to unintentional bending and is not overcoiled intentionally then ignore this post and feel free to flatten your spring.
Hey Smudgy - in the second example, the overlap was intentionally applied by the author so he could demonstrate how to correct it. Was that what you wanted to use? :)
 

RJSoftware

Registered User
Apr 15, 2005
8,516
138
63
Loxahatchee, Florida
Country
Region
My guess is that the hairspring is not a breguet as this is not same as a watch type arrangement, but it was the first thing I thought of too.

But, some quick warnings.

Whatever you do, do not cut the hairspring. The old hairsprings are very hard to replace.

Thing is the new replacement hairsprings do not have the same springing quality. This makes using the newer springs difficult as more coils required to regulate well (softer bounce) dont fit in limitted regulator loop space.

Keep in mind that most any bent hairspring (short of rediculous) can be repaired.

A 10x loupe. A fine pair of hairspring tweezers and a needle.

But, there are other issues such as forming part of the coil for the regulation loop. Pinning the hairspring. Adjusting the beat. Cone/bushing and pivot care.

RJ
 

Smudgy

Registered User
May 20, 2003
2,874
25
38
Country
Region
Hey Shutterbug. No, I didn't intend the tangled hairspring as the overcoil model. The overcoil picture is at the end of the article (last picture).
 

Forum statistics

Threads
167,167
Messages
1,456,681
Members
87,344
Latest member
Jeffbloz
Encyclopedia Pages
1,057
Total wiki contributions
2,914
Last edit
E. Howard & Co. by Clint Geller