Following a couple of months hiatus from clock making, while I made a sundial and small table for my house, I am thinking about the design of my next clock. My idea is to challenge myself to see how small a clock I can make with my current equipment.
The diameter of the main wheel in my last clock has a diameter of approximately 21 inches. My initial calculations show that, with my current equipment, I could make a similar clock at about a quarter the size, so that the main wheel will have a diameter of just over 5 inches.
The first challenge is going to be to find the right size spring for the torsional pendulum. I am exploring using a torsional pendulum suspension spring from a Holovar 400 Day Clock (also known as an Anniversary Clock). I purchased several different size suspension springs and built a crude escapement and main wheel test rig with plywood wheels to determine the combination of spring and torsional pendulum size / weight that will give the required beat (the time between clock ticks) of about 5.3 seconds.
My initial test indicates that a Holovar spring with a length of 7 3/8” and 0.004” thickness will give me the desired beat.
I am really happy with the electric powered remontoire (winding mechanism) that I have used on my last two clocks and would like to use a similar winding system on this clock. I have found a source of tiny geared electric motors that could be suitable for this clock. I have one on order to see if it will be suitable.
Unlike my last clock that was designed to be mounted on the wall this clock will be a table or mantel clock with a height of about 12 inches although I still need to complete the detail design.