|
Building Tom's Astronomy Observatory |
After many nights spent wasting vast swathes of time plugging in wires, lifting things in and out of the house, polar aligning etc etc, I decided, this summer (2004) that I would build an observatory.
Over the Christmas 2003
period we had made a concrete pier for the scope, and some time ago I had moved my imaging computers into the house
and started using active USB extension cables. Imaging looked like this:-
As you can see,
this would involve a fair bit of setup. This meant that I was unlikely to setup
if conditions were not perfect.. or there was only an hour or two before
bedtime.
We wanted a solution that was within our modest building skills, and that was, above all, cheap.
It did not need to look pretty, it did not need to be perfect. It just needed to do the job.
Our first parts shopping trip finished with 4 large fence posts, and 8 fence panels that
measured 6 foot by 3 foot. These cost about £10 each.
First stage of construction was to level the ground a bit.
I am very lazy. I calcuated the volume of earth required to be removed to level
the whole area and quickly decided not to. Then I hammered the "metpost" bases
into the ground, making sure they form a 6x6 foot square.
This also required careful work with the spirit level to keep them upright! Then we inserted the fence posts into the
bases. The green cover on the right is Pete's pier. Don't ask what the grey thing on the chair is! After taking these
images I stood on it to saw the tops off the posts!
Next, we started to screw the lower fence panels onto the posts. The bottom panels are permanently fixed with long
8mm coach bolts. Great care was taken to get everything level - particulary tricky given the ground is far from level.
Once we finished the bottom panels,
the top panels were attached with more coach bolts and wing nuts on the outside so as to be removable. We also started
the frame for the roof.
The roof was quite a challenge. We constructed a frame from treated timber, and covered it with corrugated plastic.
It is a fairly simple job to slide it off as seen below. We cannot image in that direction due to the trees. It is
simply a case of removing the panel in the required direction. The others are left up to shield wind and light.
Often, all the sides are left on when imaging zenith objects.
Inside the observatory the telescope stays setup. The
wiring runs into the house via a length of black plastic drainpipe. Inside you
can see a black groundsheet to keep the wildlife and weather out from the gap
below the panels. Being black prevents reflections, but makes it hard to find
that small hex key dropped in the dark!
The light shielding is so effective we installed a bright
white light to help with these situations. A red light is alongside it for
normal nocturnal uses. Both lights are controlled from within the house.
We also have some decking panels to stand on and a salvaged part of an office desk for storage. The white sheet is put
over the end of the OTA, and used for making flat field frames. Look here for full details of
the equipment inside.