Eric Watson, Saddleworth, England, 1986

The orrery sections

Before separation of the orrery from the clockwork drive can be done, several components that reside in the center of the upper part of the orrery must be removed. The sun globe and the inner planets gearing. A special tool was available to reach the Allen screw that held the entire module fixed to the central stalk. I was lucky to have this with the orrery. I have another, less complex orrery that was also attached to the central stalk in a similar manner and the fastener was a regular flat head screw whose head had been severely damaged and it was a near impossibility to get that screw unfastened. nothing can be done until this critical screw is loosened.

The orrery removed, left, and the calendar and zodiacal chapter rings removed.

Left, the main components of the machine. Right, who says you can't have a bit of fun with the parts? Who's to know? I won't tell.

Here I discover another bad misalignment problem that was mentioned on the prior page. This issue caused the orrery to disconnect from the clockwork drive, especially during a demonstration where everything moves much faster that in regular time drive. The demo mode is where one finds the repair issues. This required another washer shim to correct.

Here the clockwork and orrery armature minus the outer planet rings are shown. Right, the main components of the orrery which are contained in the rotating armature. Left is the Earth/Moon and armature drive components. Middle is the Sun rise/Sunset component. It should be noted that above this would also be the inner planets drive wheels and drive to the calendar and by attachment, the zodiacal chapter rings. Right the drives to the outer planets via the large 600+ toothed rings. The center clock dial is driven separately and directly from the clockwork module.

The Sun rise/Sunset center module showing the cams used to derive the correct Sun rise and set at the latitude of Los Angeles, where the person who commissioned this clock lived. In order to have this accurate for where I live, the cam would have to be re-cut, not something that I would ever contemplate. The second and third fixed gear drives are represented by the large central wheel and the smaller gear just above and showing beyond the cam armature.

Here the right hand side of the armature driving the outer planets is being disassembled.

Parts trays.

The left photo shows the drive input arbor for the rotation of the orrery armature as well as the Earth/Moon system. This is located at the end of the left hand orrery armature section. As found, the pinion that drives the wheel work for the rotation of the armature was secured to the arbor by glue, and while still somewhat secured, it was possible to move that pinion on the arbor by hand, in other words the glue was failing. The next pinion up for the Moon's orbit around the Earth was completely loose allowing one to move the Moon around the Earth by hand and, of course, failing to move the Moon in its orbit. I'm sure this pinion was also secured to the arbor previously with glue. Both pinions need to be firmly secured to the pinion. The pinion holes were too large to friction fit to the arbor. The way to permanently secure these was to dimple the arbor in the places that the pinions were to be located to give a permanent, mechanically secure solution. Doing this does not impair the ability to take this section apart since the drive gear is removable from the arbor below. Glue in this application was a no-no.

The right hand photo shows this assembly in place. The Earth sphere like the real world revolves daily, and winds its way, together with the armature, around the sun each year. The Earth is tilted with respect to the sun and this needs to move with respect to the armature to accurately represent the changing of the seasons. In most orreries there are a large number of concentrically mounted cannon pinions to rotate the planets around the Sun. Here only two are used for the annual rotation of the tilt of the Earth globe and the output to the Moon. The drive arbor is located in the center. This assembly proved very troublesome with many friction areas due to the fact the arbor as well as the cannon pinion tubes were not perfectly straight. Again, the orrery would still run due to the large amount of power delivered to the orrery, but still I felt this had to be corrected.

A close up view of the left and right hand orrery armature.

The three main components of the orrery armature, left, center and right ready for assembly.

The armature assembled and ready to be reunited with the clockwork module.

The armature on the clockwork module. Without the outer planet's rings and inner planets components.

Demonstration of orrery armarure.

Armature components.

Center armature component containing the Sun rise/Sunset module and two of the fixed gears mounted to the central stalk.