Complete final finishing of escapement, begin balance springs
- August 2016
The second balance is nearing completion for the final finish
These two photos give an idea of the quality of the polish both on the
exterior surface but more importantly the difficult to work inside curves
The pair of balances and escapements complete. Every part that can be
protected with a lacquer coating is covered. This is absolutely necessary
since it will still be a couple of years before a decision is reached as to
whether these components will stay lacquered or will have that stripped in
preparation for a flash-gold plating or even a type of electroplated clear
plastic coating. The latter is used in the plumbing industry to coat
gold-plated faucet fixtures. Either way the surfaces cannot remain open to
the air for that period of time or the entire surface area would have to be
gone over again with a final touch up.
Close up of the rear triple antifriction wheel support.
Close up of escapement and front triple anti-friction wheel support.
Buchanan now begins the first test for the rating of the pendulums. The
first photo shows a
temperature controller to obtain accurate results of temperature vs. rate. The second photo is a close up of the timer
sensor near one of the pendulums.
A rear view of the machine with the timer setup. The last photo is a screen
shot of the first test. The first trial is with the springs made from
piano wire that have been fitted last May. They are made of high strength
carbon steel. However this material has a poor performance with regards to
changes in temperature. The temperature was changed from 20.4 C to 15.55 C
in this run. The rate went from a loss of 56 seconds per day to a gain of 24
seconds; a rate change of 80 seconds over a five degree change in
temperature giving us a change of 16 seconds a day per each degree change in
temperature. So now we have two factors to consider. The first is the effect
of the physical changes in the pendulums themselves with change in
temperature and the second are the springs. The next move is to obtain a
spring material that is less or better yet impervious to changes in
temperature which leads us to Invar or some similar type of material.
Buchanan checked several sources from both the USA as well as the United
Kingdom. A Chinese source was found to be the most economical.
at $2.36 per meter x 10 meters for $12.36 than the folks out of the UK
this month for $544.38 for minimum of 100 meters. No wonder the Chinese are
kicking our asses around the world!
The astro-skeleton as of August 2016. Here we have a full view
including the stand and weights. The two weights on the left are about the
correct size, each weighing in at 88 lbs., (40 kg.) The far right weight is
missing the paper mockup weight shell and is considerably smaller and
lighter the weight immediately to its left is actually about the same size.
The left large pair of weights share both the time and celestial trains.
This was necessary since having one weight devoted just to the time train
would have involved a weight of about 150 lbs., (68 kg) with the celestial weight
needing only 25 lbs., (11 kg). The two right rights are for the quarter and
hour strike trains. Weights are made of lead with eventually
brass shell casings.