Fabricate replacement of main frame pillars - August 2013
The contours of the new pillars differ from the old ones so new potences
upon which the vertical remontoire fly fan drive arbors rest had to be
The first photo shows a trial potence done in the same manner as was used on
the old pillar. The potence now sits on a spherical curved surface, and so
cannot be left as a flat profile. The second photo shows the chamfer that
was applied by hand to the pair of potences in order to make them blend well
into the background curved surface. We also decided to change the rest of
the design to slim down the overall appearance and to use a curved profile
in deference to the new pillar surface..
These two photos show the original brass pillars verses the new design. The
additional intricacies and color contrast are obvious.
The first two photos show the old pillar and associated bevel drive up to
the remontoire fly fan assembly. Since the profile of the new pillar in this
area was larger, a recess had to be machined to accommodate the exiting fly
fan arbor and bevel.
The recess is complete and the bevel is shown in place. The overall
presentation is more visually interesting than the old design where the
vertical arbor passed through a hole drilled into the frame pillar.
One of a the new pair of main frame pillars completed.
Next an additional three frame pillars were completed. One was for the
central celestial train frame and two, shown in the third photo support the
rear cantilevered outboard support frame for the pendulums. These pillars
were tapered toward the outboard frame. The other pillars are symmetric as
they reside between two similar frames. All of the new pillars feature
refinements in design.