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Continue Sun / Moon rise set, begin dial hand drive assemblies  - April 2017


Two jewels had to be custom cut to fit for the sun hand because the sector wheel tube that carries it is not large enough to fit a standard size jewel. The first photo shows a jewel on the lapping wheel to accomplish this. Next the two cut down jewels compared to an unaltered diameter jewel, left.


These two photos show the two sector gears partially cut out which control the sun rise and set shutters.



Buchanan writes: The drive to the sun hand is complete, including the setting clutch and spoking. Next is the three final arbours on the 1 year rise/set cam drive.  This should be done by Friday I hope. I want to keep the sector wheels as much of a circle as possible, even if only 35 degrees of drive is required. Then we can make a good spoke design to accentuate them.

The first two photos are the sun hand drive, next the drive inserted into the assembly and finally the two main plates for the sun / moon drives.


The first photo shows a sweep arm that was installed where the vertical axis of the orrery is located, see white parallel line. This used to be sure that no components are created that will conflict with the diameter for that yet to be completed component. This device is clearly visible in the space between the calendar and the current sun / moon assembly. The moon anomaly variable differential set in its cradle sits to the right on the table.


Further progress within the sun / moon drive assembly. The second photo is the drive for the shutter cams.


The blank cam pair is fitted to the drive arbor. Next the wheels are beginning to fill out. There are still another twelve wheels to be added as well as the moon.


The first photo shows the sector gear pair, not yet cut into the sector shape, and the same arbor that will also carry the cam follower arms on the blank space on the arbor. Next is a view from the rear showing the mount for the dumb arbor that hold the sector gears.



The cam followers are now complete. Cam rollers are made from a pivot jewels as are all other rollers within this project. This eliminates the need for oil. The last photo shows this assembly in place on the clock. Wheel blank 216 is the input idler wheel.


The idler wheel and its dumb arbor. This wheel delivers power from the tellurion assembly to this one.

Buchanan writes: I have the dumb arbour and the collet almost finished on the idler wheel.  Once I have this finished I can depth and mount the long arbour that takes the drive to the back of the slant wheels. This means that I can then start the frames for the slant wheels.

The last photo shows the rear plate stripped of the sun / moon drive work. Note the center quick release mount attaching the entire assembly to the clock frame. The idler drive wheel is in place.


The input idler wheel. This wheel carries the drive from the tellurian to the sun / moon assembly. Notice the second, smaller wheel which was needed to introduce the correct input into the moon anomaly differential set. A second wheel meshing with the smaller wheel results in the correct counterclockwise movement of the moon.


Buchanan writes: I have the long arbour pitched now, it takes the drive to the back of the slant wheels. This is one of the few arbours that are bare between the main plates. There are four more wheels to mount at the back of the slant wheels and two wheels more in front of the slant wheel but behind the back plate. I am going to have to make a jig to find the best position for the slant wheel assembly. I need to hold it square to the frames but be able to move it and spin it around to be able to fit it in the best possible place. This is going to be fun!

See the two arrows in the second photo which shows the length and position of this arbor.


Buchanan writes: I recut 2 wheels, the large wheel that carries the gear train for the rolling moon and the out feed from the slant wheel assembly. I also cut the 2 transfer wheels to bring the drive from the slant wheel out feed to the front of the back plate. These 4 wheels bring the drive from the slant wheels to the moon arm. 

I had to reduce the size of the first two wheels just to fit them into the space available. They are actually now the size I originally drew them. I made them as large as I thought I possibly could but overestimated somewhat. In this 4 gear train I must also include the moon setting clutch. So my next operation is to decide where to place the centre line of the slant wheel assembly. Then I can decide on the frame and pillar design. I would like a single pillar but will have to see if that is possible, the main back frame of the moon dial will have to support the slant wheel assembly but I may be able to provide a rear support  to stabilize  the slant wheel assembly when it is in the clock.

The second photo shows the initial hand trial of where the anomaly differentials will be located.


These two photos show the differential set clamped into place and the rear drive wheel blanks in place. Here one clearly sees that the differential set is driven from the rear and the corrections are the output at the front and is then delivered to the moon drive. The additional two wheel blanks to the left are those depicted as the recut wheels described above.


The second photo shows the rear drive wheel blank removed to show the differential set end-on.


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