Main wheel clicks; begin escapement
antifriction wheel assembly, August 2008
Below photos show most of the parts fabricated for the main wheel click
springs. There are four identical sets for the four trains (eight clicks). Clicks will be
arranged so each pair of clicks will engage the ratchet wheel in 1/2 tooth increments.
This will give twice the number of audible clicks for each revolution of the ratchet
wheel. It's the same system used for tall fly fan assemblies. Parts count for this system
First photo showing proposed positions for the click spring feet. The
frame outline is made from paper and pasted to the clear plastic frame to test where the
feet can be placed thus determining the length of the click spring. Following photos begin
the fabrication of the escapement system. It's interesting to note that in most
conventional clock designs the escapement would be composed of maybe one or two dozen
parts; the escape wheel, the escapement pallet, crutch and pendulum. In this project the
parts count for the same components will be close to 700.
Numerous screws, all custom made. Next a shot of an initial antifriction
The eight support plates for the eight antifriction wheels that will
compose the escapement support and drive system. Each antifriction wheel will run in
Antifriction wheels in the rough showing their positions. Next the
fabrication of the bevel wheels that will drive the escapements.
Further shots of the escapement bevel drive wheel fabrication.
The design of this wheel is special. There is an additional inner ring that will be
used as a thrust bearing acting upon an antifriction wheel to prevent the wheel from
moving outward as is the case on any bevel wheel arrangement. Next two photos show
progress in the bevel as well as antifriction wheel fabrication.
The drawing is a a proposal of two designs that was submitted for the antifriction
wheel cocks. I chose the first, 'A'.
During this time the going train was able to be put to a weight to see
approximately what the power input would be needed to run the clock. The first serious
design setback was now encountered. The fabricator had miscalculated the
weight-to-duration needed to drive the clock by 100%. So the going (time) train which had
been estimated to run for 8 days on a weight of 70kg (154 lb.) falling 3 1/2 feet will, at
best, get 4 days. This is a major setback. But, in my opinion, not totally unexpected.
This design has a huge number of mobiles, and is a large scale so there is a large amount
of mass to be moved. Three feet on an eight day duration is a tough condition for even a
conventional design let alone for this one. We will address this duration issue as the
clock is made, but for now the going train will be four days with the remaining trains
being 8 days - so far. This test is shown below.