Spring drive conversion, begin polishing parts
This month Buchanan is mostly polishing parts of the main wheels and
barrels of the spring drive and other base frame parts. Further work on the
spring drive conversion is halted until hybrids ceramic bearings for these
I have one more end plate for the state of wind to modify and the barrels
are complete (first photo). Also a few more screws and pins to fit.
Next photo is a mechanically complete gear, 037 are after a little turning
decoration, (second photo). I
will be doing this to any unfinished bosses or collars.
I will be starting to polish and finish the barrels tomorrow.
I will also lacquer anything that I possibly can.
Polishing now begins on the main wheel assemblies. These form the
epicyclical winding system. Fortunately the conversion from weight to spring
drive left these untouched. Conceived in
the unusual heart-shaped spokes and planetary
gearing turned 90 degrees was first modeled in
March of 2006.
One sees as the polishing continues the vast difference in the tarnished
sections vs. the polished ones. Much of the clock also had not had the first
stages of finishing, the steps needed to remove the machining
marks on the metal surface before any finer polishing can take place.
A couple of before and after shots.
These spindles are where the planetary wheels will be secured, three for
each of the four trains.
Parts where one might think a generic component was used from outside the
firm, Buchanan will stamp the company logo to ensure that in the future
there is no possibility of making that assumption. All parts are
made by the firm
These parts arranged to look like a gold-link necklace strand. They
are the pivots that will hold the planetary wheels within the heart-shaped
spaces in main wheels
for the epicyclical winding gear. The large open hole will contain a tiny
hybrid ceramic ball bearing and the hole in the rear tab fits between a
mating fork to secure it within the main wheel.
Staging parts for the lacquering process.
Twelve planetary wheels, three for each train. See how these were polished
in the video below.
Here one will see the entire process of polishing a large-sized bevel
wheel in 'real time', 32 minutes. The larger the wheel, the more time
consuming this process is. A bevel was chosen because these are also more
difficult to do than a conventional flat wheel. One comment made by Buchanan
in the video is very important to this process and that is that he cuts out
the wheel spokes as accurately as possible using the jeweler's saw so as to
minimize the finishing work required at this stage. Blades are very sharp
and the saw has been specially converted to run at a slower speed. The time
consumed at that stage, is made up in the finishing procedure. Listen
carefully to the monologue, this is what is important in this video; the
explanation of the process. It is rare to be able to sit by the side of a
true expert to see and hear how he performs his work.
The screws on this Sun gear look like yummy blue candies just waiting to be
The first photo shows a supply barrel with the motor spring wrapped
around it. Notice the thin wedge that now holds the spring to the hub, where
Buchanan has made the “constant radius curve”.
The blued screws give a nice punctuation of color to the background metal,
Here we can see the interplay of the different colors of metal used in this
project: Arbors - stainless steel; lower train wheels-pink bronze;
supporting barrel-yellow brass; (as well as all other wheels above the lowest
train), and blued screws.
I have the spring barrels finally assembled with the springs fitted to the
take-up drums. Tomorrow I start on the lower main frame, machining mounting
holes for shipping and then onto the selector lever for the demo drive.
One of t
he mounting holes for shipping is seen as the newly threaded
hole in the second photo.
his photo shows the dramatic difference between a
tarnished frame from 2009, to the frames now being treated. Of course the
tarnished frame was exposed without a case since then, but more significant,
was subject to repeated handling over the years.
Buchanan's Bluing Oven
There are over a thousand screws that need to be blued to a consistent color
as well other parts like decorative rosettes and other levers. To do this by
the classical method of heating over an open flame, or using a hotplate to
heat parts sitting in a pan of brass filings would be prohibitively taxing
in the time needed. Also achieving a perfect uniform color across so may
parts both in number and configuration would be difficult. So Buchanan
tackles the problem by creating a precision bluing oven.
I collected up all the screws for the state of wind mechanism, there were 86. I have always blued the screws on a brass plate over a meth’s
burner. This takes forever to heat up and temperature control is
nonexistent. It also makes bluing a split second exercise. (The need to
quench the part just as it achieves the right color to stop the color
I have thought about this for a long time, but, with all the screws that are
needing bluing in the next while, I thought I must do something about it,
first, better temperature control and also convenience and more time to
decide the best color. I found this interesting description in Wikipedia:
“If steel has been freshly
ground, sanded, or polished, it will form an oxide layer
on its surface when heated. As the temperature of the steel is increased,
the thickness of the iron
oxide will also increase. Although iron
oxide is not normally transparent, such thin layers do allow light to pass
through, reflecting off both the upper and lower surfaces of the layer. This
causes a phenomenon called thin-film
interference, which produces colors on the
surface. As the thickness of this layer increases with temperature, it
causes the colors to change from a very light yellow, to brown, then purple,
then blue. These colors appear at very precise temperatures, and provide the
blacksmith with a very accurate gauge for measuring the temperature.
Steel in a tempering oven, held at 205 °C (401 °F) for
a long time, will begin to turn brown, purple or blue, even though the
temperature did not exceed that needed to produce a light-straw color. “
So; a long time at a lower temperature should make bluing less critical, I
had known this subconsciously. I ‘discovered’ it when I blued the wire for
the Pouvillon orrery.
So... I made a bluing “machine” It is an aluminum block with two electric
elements inserted in it and a proper temperature controller inside an
insulated box, with a glass lid. Now I can flick a switch and in a few
minutes I know the temperature will be correct and it will always be
consistent. It is also draft proof. The naked flame fire danger is also
Here the oven
demonstrates the range of colors it can produce. Notice the
desired electric blue color is at the end. It is the last color the metal will produce
before it “goes too far” if it were overheated and the color then turns to
an unattractive pale blue. All of the other colors can still be restarted
from a lower temperature color without having to redo the process which
requires refinishing the part and starting over. This makes bluing to this
color by ordinary methods difficult as one must be quick to quench the part
before going too far.
Example of blued screws and a rosette.
Other miscellaneous tasks
Buchanan also takes care of some unfinished items that have been left over
during prior construction. Here a cock, or more properly termed, potence, had been temporarily super glued to one of
the the eight base frame pillars which hold the main wheel arbors (it is the
left, front corner pillar). This serves as the lower pivot for an arbor
driving the equation of time kidney cam and was
first fabricated in October
2014. The temporary attachment point with the the equation arbor
worm drive installed in November 2014. The reason it was glued in
the first place is that the positioning of the arbor is on a critical angle
so as to mesh properly with the equation kidney gear and the drive off
center and above and both needed to be fully tested before permanent
These photos show the components involved with the four state of wind
indicators. The second photo shows the sector gears that transmit the
movement of the spring barrels winding or unwinding to the dial hands.
Buchanan begins to fabricate the bezels for each of four enamel sector
dials indicating the state of wind for each train.
The state of wind indicators turn out to be serendipitous. When they were first
designed the clock was weight driven, given that one can easily see the
state of wind simply by looking at where the weights were in relation to the
available drop these were basically added "because we could". Now that the
machine will be spring driven, the state of wind cannot be determined
without such an indicator, and given that there are four trains that run
independently, it is critical for all trains to be properly wound. It is
true that for a full wind up, there are Geneva stops to ensure that there is
no over-winding damage to the motor springs and that all will begin at the
same point. However, should something go wrong, causing a train to stop, say
the the celestial or strike trains, it could go unnoticed for a time, unless
one looks carefully at the dial work, but a cursory glance
at the winding dials will very quickly show a problem.
The delicate bezels with the tiny blued screws perfectly frame the
enamel dial work, and the dial hand is currently a mockup and will later be
replaced with blued steel. It is shaped so as to allow the winding arbor to
pass through. One might wonder about damage from the winding key, but the
arbor square will end well before it reaches the dial hand so the key shaft cannot