Finish celestial train demonstration drive and orrery output gearing -
November 2013
This month we finish the orrery output gearing needed to manually
demonstrate the orrery in both forward and reverse. During this time we begin the sculpting
of the movement's frames, bridges and cocks.
The above photos show the build up of the orrery output gearing. The fourth
photo shows the drilling of a wheel to accept screws which secure each wheel to
its arbor collet.
Next Buchanan begins the orrery clutch. This is represented by the large
wheel blank in the second and third photos. The clutch will allow the user
to manually adjust the orrery apart from the demonstration drive. But the
most important reason for this component is to protect the complex
gearing that will comprise the orrery should there be a jam anywhere within
that system while the demonstration crank is being turned.
Next the clutch wheel is spoked out and the remaining components fabricated
including a fancy knurled knob.
The clutch is next mounted within its frame and then within the context of the
orrery drive subassembly.
One does have to admit that it would be tricky to get ones fingers between
the delicate antifriction wheels and around that knurled knob! But as
previously mentioned the real function is to protect the orrery during
manual demonstrations.
During the past several months I discussed with Buchanan the idea of making
the overall design of the clock's frame components more refined. While these
components cross sections are beautifully curvilinear, their front and rear
surfaces are a flat plane. The first photo shows the considerable difference
between a sculpted component in the background and the untreated one in front. The
second photo gives another view. It should be noted that the machined
sculpting is performed equallyon both sides.The result I think, is striking.
The rest of the escapement is now assembled in front of the orrery drive
unit. Note that the upper bridge support sports the contour sculpting on the
curvilinear arms.
A close up of the sculpted upper bridge support and end view of the drive
unit.
This video shows a demonstration of the completed orrery drive assembly.
Now begins the sculpting of the frame components that have already been
fabricated over the previous years
On those frames, the strike frame shown here, that have been fabricated
before now only the frame's arms or the "branches of each tree" which
comprise the forest of this fantasy machine can be machined. The areas that
hold the pivot bearings whether they be jeweled or roller bearings must
remain untouched. This is necessary since the corresponding arbors and all
of the wheel works they support have already been made and so these areas
cannot be changed. This is in contrast to the first photo shown earlier in
the orrery drive where the entire branch with the pivot area was machined. That part was done
after we decided to commence with the contouring of the movement frame
parts. As with a real tree, the lower branches are thicker than those toward
the top. The contouring is done equally on both sides of each frame.
One might ask "what about the large, vertical flat area of the frame?" Well
this is the tree's trunk and will later have an articulated "barked" surface
employing an EDM machine. That surface will be within a polished perimeter
that will encompass the frame's edge like a picture frame. We decided to do
this not only to accentuate the idea of the frames as trees but to reduce
the large mirrored surfaces that these parts would represent if the entire
area were polished. Too many large mirrored surfaces would be disruptive to
the viewer and obscure an intelligible interpretation of what one was
seeing; the effect being like a 'carnival house of mirrors'.
The first photo vividly shows how much of the frame Buchanan was able to
reduce on both sides. The next photo shows the front celestial train frame
undergoing contouring, these frames are the most complex set in the clock.
Close up sections of the contouring process.
The rear celestial frame is shown joined to the rear pendulum support
bracket.
This photo shows the sculpting to full effect. What we see here are the
ripe, red fruit bulging at the ends of each tree branch. The pillars joining
the rear pendulum bracket have been changed from brass to stainless steel
and have been tapered and decorated at each end. The pivots provide a
spangle of red, which when combined with the blued screws and silver pillars
give a beautiful set of colors spread over the gold backdrop of the
organically shaped movement frame structures.
The trees will contain the forest of wheels and arbors and within that
forest there will be allegorical birds and snails. Above that forest will
hang the firmament as represented by the sun and planets of the orrery. This
machine is designed not only as a timepiece, but as a moving, living
fantastical mechanical world.
And lastly just for fun...Buchanan has assembled the entire celestial train
with attached escapement assembly all precariously held by one frame piece
on the corner of the bench, many hours worth of work displayed.
I hope the vise has a good grip!!!