Of course you're quite right about that Wayne. Its the challenge. I have had "drives" to improve my own collection of 400 day models. It worked for a while but only for months rather than a year. I'm talking about timekeeping primarily. They have it in them to be very good. As you say - brass is not near to being ideal. However towering over all else is the challenge of flutter. Unless that is quelled other things aren't worth too much effort. Of course timekeeping is not the only thing these clocks offer. They are a fascinating ornament. An intriguing piece of mechanical machinery. How well do I remember the very first one where I would have happily settled for it to just maintain! That very same clock has just come back into my ownership and after a clean-up etc it runs very well indeed. Fascinating stuff. Thanks for your reply. Best rgds, Berry.Berry, if it was too easy it would not be fun.
Flutter can be defeated, but temperature changes are the weakness of most 400 day clocks. The horolovar suspension springs are supposed to have a flat modulus of elasticity so ambient temperature changes don't affect spring rate. I've tried freeze spray on one horolovar suspension spring before and the rate did not change, so it seems to be true. Now the pendulums are another story, just brass which is highly affected by temperature.
The Atmos is a different beast, its kept fully wound for constant power and from what I have read there suspension springs are specifically processed to have a negative modulus of elasticity which compensates for the pendulum thermal expansion coefficient. Almost makes me want a little heat treat oven.
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