This month the
components within the time train frames are polished and reassembled as well
as other small housekeeping items that have been left over from prior
construction. The time train does not, however, contain the escapement, it
is driven from this train but is located within the celestial train so it
can be located in the center of the clock. The bulk of what is in this train
is the complex dual remontoire, and the sidereal time complication.
Additionally there are other components and equation of time complications,
these will be added next month.
A real treat is the video of the reassembly process. Anyone who has
tried to reassemble a three-train quarter chiming movement usually finds
getting all the pieces and arbors into their proper place to secure the
movement plates to be a challenge. This takes the job to an entirely new
This also touches upon the first major design change that was made in the
project in March of 2009.
At that time it became apparent that the original basic frame design based
upon a plate-and-spacer configuration like that of the quarter chiming clock
movement would not be desirable. While there would have been many smaller
sub-frames within the main outer plates, there was no way to make this
design practical for the scores of disassembly and reassembly cycles needed
throughout the construction process. The main outer plates would also have
been large, heavy and unwieldy to try to fit many dozens of wheels
simultaneously. Our solution was to make three modules based on a hybrid
pillar and frame and to mount those to a common base frame. In this way the
reassembly can take place in smaller segments making the process as well as
any future servicing an easier task, or at least as easy as can be expected
for this machine. See two photos below.
The time train module before disassembly for polishing. As was described
above, there are no conventional frames, but a series of pillars. This was
the first type of frame design used in horology, and was seen in chamber and
tower clocks from the 11th century; known as 'bird cage' frames and
recognizable for their open architecture and is shared with the time train
Another view of the time train module before disassembly for polishing.
All of the time train parts are laid on the table. Notice how dull and dark
the parts are. These were first completed in July 2008.
These photos drive home the difference between the parts before and
after polishing. Recent photos and videos of the machine before the current
polishing process did not fully reveal the extent of the tarnish, while it
was obvious that the parts were not fresh, the real impact of the tarnish comes
through when the machine is dis
One can see just how darkly tarnished the parts have become over the years.
Hopefully with the frame pieces lacquered and the clock in a proper case,
protected from handling and in a clean environment this will not reoccur for a very long time.
Here are two of the
ongoing housekeeping items. The first photo shows a beautifully turned
collet and what a similar collet looks like before. Another example is the
installation of a biasing spring, arrow, to better secure the sector gear’s
following arm to the perimeter of the equation of time cam, second photo.
The first photo shows the remontoire fly fan frames, the next photo shows a pair
of flies that compose one of two such assemblies (a total of four flies).
This close up photo shows the design of within each blade is actually a "B"
for the Buchanan firm.
These three photos show more of the remontoire components.
The second photo shows the same part close up as that seen in the lower
right hand corner in the photo just above. It serves as part of the
splitting differential within the remontoire is made to look like the main winding
wheels located in the base of the clock, first photo from
It performs the same function;
having planet wheels located in the three spaces just as in the winding
wheels. The main wheels are about five inches in diameter (12.5 cm) while
this part is about two
inches (5 cm). This attention to design consistency is a part of what sets the
Buchanan firm apart.
This photo shows the
dual remontoire trip release cams. Each cam makes one revolution every two
minutes, the four arms result in the remontoire being released every thirty
seconds; since the cams run in a fashion where the arms are staggered
between each other the result is a release of one of the pair of remontoire
fly fans every fifteen seconds. There is a small spring between the cam and
its drive wheel to cushion the sudden stop when the cam locks, preventing
the large remontoire cages from jarring.
These photos show a partial build up of the remontoire rocking cages.
These three photos show
the remontoire splitting differential which allows the dual remontoire to
operate independently from a single drive input.
This is the heart of
the dual Wagner remontoire and is performed by the part described as a
sister to the main winding wheels; and is the cage
in the center
holding three planet wheels.
The frame parts are now
polished and lacquered. Look carefully at the beautifully milled square
areas just above the open holes on the two lower frame pieces. These will
serve as a classical base to the Tuscan style columns that support the
remontoire fly assemblies
, they also support the pair of remontoire
Sidereal time complication
The main components of the sidereal drive complication.
The two rings on the lower right are the
minute and hour dial bezel mounts that rotate counterclockwise.
the delicate taper of the spokes in this and the following photos.
The Buchanan logo is stamped on the outer dial bezel mount, first photo.
Next a close up of the eight screws that secure a large delicate wheel to
Just a twitch of the hand would be enough to deform these precision parts.
Imagine the care needed when they must go through the polishing process.
This photo illustrates Buchanan's ability to combine precision fabrication
and artistic ability. The actual size of these parts is a little over
inch (4 cm) in diameter. This is part of a very decorative caged roller
In the first photo components from the photos above are installed.
The second photo shows the layers of components within this part.
The sidereal time complication completed with the decorative caged roller
bearing at the center.
Parts count at this time is 1699.
Another example of Buchanan's work. This photo is approximately 5 times
magnification. Even at this magnitude the part looks perfect in terms of
polish of the pinion and wheel surfaces, the sharpness of the spokes and
wheel edges, the color of the blued screws.
This photo is the time train clutch mechanism. Look at the beauty and balance between
the blued spring steel used as the gripping force against the same spoke
configuration of the wheel held by turned pillars and all this is moderated
by the pair of precision knurled adjustors.
This video shows the reassembly of the time train. Notice in the first two
short clips how long the splitting differential coasts until it come to a
stop. This is a demonstration of the extremely low coefficient of friction
the ceramic ball bearings have compared to conventional steel bearings.
Reassembled time train
In these photos the frames nearly disappear amongst the forest of wheels -
exactly the effect I was looking for.