Spot Observatory
The observatory  building is 15 by  23 feet, with two piers.  The rails are 32 feet
long, permitting the roof to be rolled approximately 8 feet from the building. The
walls were set at 7 feet, and roof pitch at 5 in 12, permitting a standard door,
plenty of headroom  and good wind protection.  The roof  is motorized.  For details
of the expansion of this building in the spring of 2005, and for a few photos of my
first observatory built in 1977, click
Milky Way
Solar System
New Images
Left: The old roof
mechanism, made
from an old
reversible winch
and pulleys with a
practice bomb  
tensioning device
for the cable loop.
The observatory with sculpture by Nashville
artist Rusty Wolfe.
Above and to left: The new
chain drive roof mechanism,
with a reversible DC motor at
the end of the roof rail
structure.  Limit switches
stop the roof automatically
on each end of its run.  With
the motor outside the
building, and with higher
quality gears, the mechanism
is substantially quieter and
quicker.  Click on thumbnails
of internals for larger version
of gearing.
Roof vents and interior reflective ceiling to minimize
daytime interior heating, installed June 2011.
Painted white in September
2012 for better thermal control.
Optical park
position sensor