After running reliably for a few weeks my latest clock – “Horus” – is keeping good time and is now available for sale ($1600).
Horus – The Smallest Clock from Cedar Clocks
The clock is available with a choice of hand colors. Light natural lacewood hands or black dyed walnut hands. Once can also have a combination of the two colors that like.
Choice of Clock Hand Colors
The clock is powered by a small electric motor in the remontoire re-winding mechanism. The power for the electric motor can be provided by either four AA batteries in a walnut wood battery pack or from a small plug-in transformer.
Battery Box
Plug-in Transformer
Additional information about this clock and my other clocks can be found at the purchase tab of the Cedar Clock website.
After a long gestation, the smallest clock I have made so far (approximately 16 inches high, 6 inches wide and 5 inches deep) is complete and running well.
I have named the clock “Horus” after the Egyptian god of the sky as its shape is reminiscent of the sign for the eye of Horus.
The clock is powered by an electric powered remontoire (winding mechanism) that rotated around the winding wheel approximately every 15 minutes. Because the clock is so small the 9-volt battery that powers the remontoire motor is located in a separate battery box that is connected by a cable from the back of the clock. I plan offer an option to power the clock from an electric outlet using a small transformer.
I was concerned that achieving the tight tolerances required to construct a clock this small would be a challenge. This did not prove to be a problem, but I struggled finding the right combination to torsional pendulum spring and weight as well as the correct dimensions for the pallet fork to get the clock to run well. After considerable experimentation with different spring thicknesses and pendulum weights, I found a combination that works well.
On my previous clocks I have not had any issues with the wooden wheels (gears) warping. I originally use three layers of 1/16” thick walnut, with the grain in alternating orientations, for the main wheel of the clock. Initially, this looked great and the clock ran well, but over a few weeks the wheel gradually warped until they looked like potato chips and the clocks stopped running. To solve this, I created wood laminates from 1/40” thick walnut veneer. I remade the main wheel uses 7 veneer plies and the other wheels 5 veneer plies, alternating the grain direction. The clock had been running for a few weeks with the new wheels and there is no sign of warping.
I plan to run the clock for a few more weeks before I offer it for sale.
As the Mini Clock escapement and wheel train test rig has been running well, I have been designing the complete clock. The overall design is similar to my last clock “Electra 2” (https://cedarclocks.com/photos/) but much smaller and rather than wall mounts, it has a base so that it can sit on a table.
Current Design of the Mini Clock
The clock is approximately 14.6” high, 6.0” wide and 5.1” deep. I am fairly happy with the overall design but being a small clock, it does not require much wood so, if I decide I do not like the design, I could redesign and re-make parts without a huge cost.
The next step is to start cutting out the components primarily from walnut wood but I plan to use lignum vitae for the pallet. Lignum vitae is a very dense wood that has self-lubricating properties that is ideal for the escapement pallet. I will start by cutting the components of the escapement and wheel train.
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.
Mini Clock Escapement & Wheel Train Test Rig – The Main Wheel is 5.7 inches Diameter with 125 teeth
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.
