Fabricate movement stand, inner steel structure - October 2012                         

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Depicted above is a drawing for the clock stand Buchanan had submitted in September 2009, shortly after the redesign of the clock frame from the original plate and spacer to the current pillar frame configuration. He had anticipated at that time that the new frame design with its long narrow base would not be sufficiently ridged to avoid the various stresses in the base structure from the weights to prevent a shift in the pillar uprights which would cause the wheels to bind. This is easy to imagine if one thinks about the base deflecting downward from the mass of the clock weights and all of the long, upright pillars that contain the wheel works being pushed inward toward each other from that deflection.  It is a tribute to Buchanan in that these issues were anticipated long before the actual article was made.

Next I began to get some detailed photos of the steel stand that will hold the clock. It is built to withstand any ‘racking’ that could occur from an uneven floor as well as from the winding process and the combined mass of the clock and its four weights. Any unevenness transmitted to the clock base frame will result in slight distortion of that base frame and when translated and magnified through to the long upright frames that hold the movement’s wheel works, the clock will cease to function because of the change in tolerance between the wheels from frame to frame. In short –a binding between the mating wheels. From the first two photos it looks like Buchanan is using the same type of angle iron that is used to hold a course of exterior brick work over a window, in other words a lintel. The angle stock is about 1/8” thick. The third photo shows the table top of the stand's structural ‘box frame’ being built up.

The interior cells serve as additional stiffeners for the platform that will serve as the base to support the clock frame. The second photo shows a detail of one of the numerous welds. Next the entire base before the welds are ground flush to the surface.

 

These photos show the base with all of the welds ground flush and positioned next to the clock .

This series of six photos show the beginnings of the system to allow a limited degree of mobility to the entire clock. This is necessary, since without this ability the clock would have to be removed from the stand to have any hope of two people being able to move it even with the weights removed. This would be too dangerous except in the contingency of it needing to be relocated to another place entirely. But for the purposes of being able to move the clock to clean, or make changes to the floor or carpet that it may be standing on, or to move to another location within the same area, another way has to be found to allow it to have limited mobility without the need to remove the clock from its stand. These photos show a wheel mounted to an assembly that will allow them to be fully retractable. In this way the weight of the clock will only be borne by the wheels when they are in actual use. The rest of the time the weight is transmitted to the floor directly through the frame structure.

 A threaded rod is welded to a toothed cog wheel and is shown in the first and second photos. The third and fourth photos show the rod inserted into a mating, threaded hollow tube which, in turn is welded to a plate that will become part of the base of the clock stand. In this way, when the cog wheel is driven in forward or reverse, the wheel will extend or retract.

The stand legs are being fabricated in the first two photos. Next photo shows the various components assembled to fabricate the stand base.

The first two photos show the intricate clamping needed to assemble the metal box that surrounds the threaded rod and cog wheel that is involved with the retractable wheels. The assembly is now ready for welding. The four individual boxes are now welded as seen in the last photo.

Next the lower frame cross members are assembled and in the next photos welded into place onto the four corner boxes containing the wheel retraction assemblies. It should be noted that the uprights are not welded to these same boxes, but are held by an internal treaded rod; allowing for the disassembly of the stand.

This series of six photos show the fabrication of the upper stand which will support the clock base. The third photo shows one of three attachment points between the clock stand and the actual clock base support as represented by the silver box with the four openings which are there to allow the weight lines to pass from the clock to the drive weights below, fourth photo. These points are not solidly attached but allow for some flexing between the rest of the frame and the central box base that supports the clock. In this way any uneven floor that the stand might encounter is corrected by this arrangement. The fifth photo shows the three attachment points with the last having the central box mounted in place.

Further photos of the stand fabrication. The first two photos show the threaded rods which are inserted into the metal tubes that will serve as the legs of the stand. These will be used to snug down tightly the tubes to both the lower and upper sections of the clock stand. The next photo show a close up of one of the three attachment points for the clock support bed to the rest of the stand as outlined in Buchanan’s original drawing of September 2009.

This photo shows the clock on its temporary stand next to the permanent stand being fabricated. Note the completed Pouvillon astronomical clock being readied for delivery in the background.

The next photo shows another of the three attachment points for the clock support bed to the rest of the stand. To be honest, I think that given the robust construction of this entire assembly, the stand would be so rigid as to not have the need for the three attachment points in the first place, but we are going the 'extra mile' as always in this project. The last photo shows the eight points that will ultimately contact the clock base to keep it perfectly level. They are located directly beneath each winding drum for maximum support. The assembly is attached the milling machine to plane them down to make all of these attachment points perfectly level.

 

The central box is now in place upon the three attachment points within the upper stand table. The eight holes will each receive a pin that will mate with a hole drilled into the clock base. These pins are just the right length to hold clock imperceptibly above what will later be the decorative wood surface that will cover this area. The entire structure is coated with a rust inhibitor. Notice that the clock is now disassembled to its main subassemblies. We are now beginning to replace the original ball bearings with the updated ceramic variety to achieve our goal of making this clock a 'dry runner'.

The next two photos show the gear box with crank in place that will drive the bicycle chain connected to all four retractable wheels. Next is a close up of the chain drive from the side that is affixed to the base of the clock stand through the four bolts shown.

Next a view from the front edge. Next a view of one of the four corners that the chain circumscribes and meshes with the gear cogs that will move the stand’s wheels. This system allows for the uniform raising and lowering of all four wheels simultaneously so that the stand is perfectly level at all times. Finally, a view of one of the corners; here we see the wheel extended with the stand foot just off the ground.

We see now that Buchanan is not only an expert clockmaker but iron worker as well! The entire structure will be clothed in a wood exterior and decorated with ormolu appliqués.

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