New Haven mainspring question

[Richard S]

This is in a small New Haven upright mantle clock, although the movement is not marked in any way. I assume it is original, but I am beginning to question that. My question is about the mainsprings-they are quite different sizes (strike vs time). The time side is .012x7/16x84 inches (about), and the strike side is 0.019 x 7/16 x 84 inches (about).

I have never seen a clock with two mainsprings so different--one seems too weak, the other too strong. I hope someone is familiar enough with this movement to know more about what was original. I might just put it back the way it was, except I am working on it for my mother in law, and I would kind of like to put it right. Thanks in advance.
Richard

[Willie X]

Richard,

Yep it's a N-H. I have one of these on my mantle. Mine has equal strength springs closer to the .019". New Haven made quite a few of these 'smaller' Kitchen clock type mvts. Many have wrecked great wheels or worn out great wheel teeth, from the strong springs I surmise. They are good runners but all the spare parts mvts are long gone, or at least picked clean of the parts I need.

Good luck, Willie X

[Veritas]

Willie i know this is not a purist thought, but couldn,t someone put in a weaker spring, if these springs are so powerful?
I have a new haven that i need new springs for.

[shutterbug]

All American clocks were purposely over powered to provide 'longevity'. Most clocksmiths were aware of this, and probably substituted weaker springs whenever they were replacing a broken spring. That could account for the differences in your movement. As a rule, both springs were equal from the factory. The "habit" of replacing the originals with smaller springs is well founded in principle, and will decrease wear on the pivots and bushings.

[Richard S]

Thanks a bunch folks. I am aware that there was a tendency to overpower the clocks so that they would run longer. Looks like the heavier spring was the original one. This little guy has had a rugged life-the rear pivot for strike arbor #2 was completely out of its bushing, jammed on the outside of the plate (you can see it is at a different angle in the picture) so it didn't strike at all. The plates are about as warped as you will ever see (thin plates--1.5 mm). Bushings fell out when I opened up the movement.

It seems to me that since the time side was running OK before dismantling, I will just order a new one that is more like it for the strike side, and throw the original away. That, and some TLC and it should be fine. Thanks again.
Richard

[itbme1987]

if thats true then my aunts beehive must have the originals in hers....i snapped the winds off the key winding it

[Willie X]

Ver,

I think that a slightly weaker spring would be a very good idea. Especially with problems that these mvts are prone to.

On the other hand I do really like the loud ticking and wide pendulum swing.

BTW, the one I have it is only in average condition and will still run for about 12 days, if I forget the wind it.

Willie X

[Veritas]

I replaced a mainspring in a new haven school house clock a few years back. At the time i just thought replace with what it had in it. If i remember right it was .017 ins thick. I am now thinking i should have used a weaker spring. As it is this clock wont be running on a daily basis so less wear will incur.
I do like the loud ticking of clocks.