Roll On/Off
Building my Roll-off-Roof
Observatory.
I hate carry my gear from the House to
the yard all the time. I am fairly strong but carrying the
mount itself is heavy and awkward. I decided I needed an
observatory. I looked around the web and was considering a
Sirius, but they were too expensive. Then I nearly
bought a
XL3 Skyshed pod clamshell, but the wait was too long and
people complained about water leakage and the inability to
view the zenith. It looked like a good week for a DIY
project.
I started out by finding a location in
the back yard with the most sky view and then applied to the
wife for a building permit. I decided to make the roof
slide over an existing water tank to save yard space. I
liked the roll-off-roof design as you can see the whole sky
when slewing around. Looking at the conventional styles I
felt claustrophobic, only seeing a small slit. The
additional expense of roof movement for unattended imaging
was also prohibitive.
(Yes the tree had to go)
I drew up plans checking
there was enough room for a desk and the full movement of my
longest OTA. Then the frame went up.
I used steel for the roof rolling track and gantry over the
tank. The remainder was from treated timber pine.
The roof rollers are automotive
bearings that run in lipped channel steel.
Next step was to pour the concrete
floor. I dug out the floor for 100mm of concrete that would
be steel reinforced. The concrete beneath the pier was 1 m
deep (into the clay layer) and 1 m wide each way (1 cubic
meter). This is required to minimise vibration and
movement.
The remaining jobs were to finish the
roof (0.55mm colour bond) on a 25x25mm RHS frame and clad
the walls. I used fibro sheet on the inside and timber on
the outside to match existing features on the house. I
built a desk in the corner and some shelves as well. The
room has dim-able red lights and power across to the pier.
Before I put the pier down I installed
vinyl flooring to keep the dust at bay and some added
insulation bats and foam inside the roof area to stop
condensation drips. Then I painted the inside walls a light
colour so later I could take flats of it.
Hence, an observatory for half the
price of a commercial one!
The plans are below:
Roof Rollers
Plan View
Side View
Roof View
