Back Up Next                 Initial drawings from fabricator

In April of 2004, while the fabricator was working on my friend's commission, a few preliminary design idea drawings were prepared using some of my suggestions. Maintaining power was to use what I consider to be the best type which is the planetary gear system, rather than the more common Harrison spring types. Notice the planet gears are turned 90 degrees to make the effect more interesting rather than on the same plane as is normally done. This design was later adopted, and all four main wheels will be equipped with system even though it was only necessary to do this on the going and celestial trains. The second drawing is the anti-friction wheel system which was also eventually adopted to support the two H1-type balances. The design is reversed from what one would normally expect. The balance arbors do not rotate between the wheels. Instead the wheels within the cage are fixed to the balances and this entire assembly moves back and forth on a fixed arbor.

  Astro early fab draw.jpg (167791 bytes)  Astro early fab draw (3).jpg (215432 bytes)

Below is a view of the anti-friction cages as they would support the balances. At this point the fabricator had chosen a more modernistic design for these. Later this was changed to more conform with Harrison's original look. Next is a concept for the remontoire flies that we call a compound fly. The internally toothed ring will allow for a fly to not only turn but also pirouette around each other. Later we went with a four-bladed design for each of the two remontoire flies. The strike train flies are based on a design by Fasoldt that also pirouettes.

Astro early fab draw (1).jpg (262759 bytes)   Astro early fab draw (2).jpg (201329 bytes)

Below is an initial concept for the frame. Again this is at the time I was still thinking in terms of a tower clock designs. This was later abandoned in favor of a more conventional pillar and plate configuration. The center structure is for the remontoire and this was later flipped upside-down as is commonly seen in clocks that use this type of swinging frame remontoire.

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Later in January 2006 a second set of drawings was made in preparation for the creation of a working model of the escapement and remontoire in plastic. This working mockup was necessary as such a system had never been made before. By this time the fabricator had finished his earlier commission for my friend and was now working on this project as well as a smaller commission from me.

The first picture shows the concept for the dual, counter-rotating escape wheels designed to give a kaleidoscope effect between the swirled spokes of the wheels as they would appear superimposed upon each other. (a video of a the operating plastic mockup shows this effect). This was an idea contributed by the fabricator and it's significance caused me to change the design to have the escape wheels in front of the clock as opposed to the rear. The second diagram shows the concept of the dual remontoire being driven by a differential system (as designated by the box gear system labeled 'I'). Each of the two remontoire drive one of the H1-type balances. In turn each of these balances drive one of the two escape wheels. What keeps the system in synch is the fact that that as in Harrison's original design, the two balances are mechanically slaved together.

Astro early fab draw (5).jpg (2089911 bytes)  Astro early fab draw (8).jpg (316287 bytes)

This drawing shows a novel way of getting a bit more drop from a limited fall. To the best of my knowledge this type of compound barrel was only used once before in a Martin Burgess' design for a sculptural clock and was adopted in the final design. See the mockup.

                                                            Astro early fab draw (7).jpg (1221465 bytes)

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