Fabricate replacement of main frame cross pillars - July 2013                        

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During the hiatus of nearly two years in this project, Buchanan was able to identify several several items that needed attention in the mechanism that has already been built. These are what one would call 'bugs' and they were corrected over the next several months. I will not go into those efforts here but will continue only with new fabrication. Also during this time I had decided that I wanted a few minor changes in the design. In the meantime the clock mechanism had to be completely disassembled to perform these functions. It takes two days to disassemble and another two days to reassemble the machine at its current level of complexity.


The first photo shows the clock operational, before disassembly. Next the pendulums and escapement pallets are removed.


Rear view of movement.  Next is the front view with the center module removed. That module contains the escapement and pendulums and the celestial train with Robin remontoire. Later the main orrery and its dual speed demonstration drive will also be located within this module.


The removed central or celestial train module. Next a view from the rear showing the strike train module still in place. The going train module is removed. One now can see much of the base frame holding the four train drive wheels.


The clock is now semi-disassembled. I sure hope nothing falls off those tables and gets lost! 

The first change I asked for was that the clock will dispense with the horizontal main frame pillars that have already been made in brass and that these will be replaced with stainless steel. This is in keeping with our choice of this material for all steel parts because of its resistance to oxidation. The exceptions are the arbor pivots and the parts that will ultimately be heat-blued. The former needs metal that is harder than stainless steel and so we will be inserting a tool steel pivot into all of the stainless steel arbors that will rotate within jeweled bearings. The latter needs a steel that has a higher carbon content than stainless and also the nickel content in stainless prevents it from bluing properly. I think this change will add more color contrast to the project and gave me the opportunity to get a more detailed and decorated set of pillars. For Buchanan the two main pillars that had previously had holes through which the two vertical remontoire fly fan drives passed through, were redesigned to allow for an easier process through the many disassembly procedures to come. The second change is a decorative alteration to all of the main frame plates which will be described in a later section.

The first two photos show the steel billet and initial machining. The third photo shows the two new stainless pillar blanks above one of the current brass pillars. The fourth photo shows the change that Buchanan made in the pillar design to allow the remontoire fly fan assemblies to be serviced without the removal of the frame pillar. Next the decorative end collar rings.


Here we have the trial fitting of the new pillar.


Next the center access area is machined out. This is what allows one to remove the fly fan arbor without removing the pillar.


Here the pillar is in an EDM machine making the special tapered holes that will positively key the drop down frames to the pillar. A conical, threaded screw will secure these pieces; similar to the ends of the parts shown on the right. The positioning of the frames to the pillars is critical. Those frames contain the remontoire cages and any deviation or movement would cause a failure of the time train.


The conical screws are now shown in place securing the drop down frames. Further embellishments to the pillar will follow.

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