The internal fittings
You may remember that the electricity came into the pad through the floor. I needed a spur
off that for the lights, intruder alarm and power socket which were fitted to the wall frame and a corner
post, and also a spur to supply electricity to a RCD double socket on the pier. This was done before the
floor was fitted.
Firstly the shed base rail was sealed against the concrete on the inside and out.
Then I covered the floor with a plastic membrane and sealed it against the base rail. If any water does
get in it will stay under this and not up into the flooring and carpet. The electricity cables were run on
top of this where they had to cross the floor to the pier and to the corner post you can see below.
Electricity and lights
All wiring was placed inside plastic conduit that has a sticky rear (available at B&Q)
so it stuck to the metal walls easily and neatly. I have one white fluorescent light and another on the
other side of the observatory fitted with two sheets of dark red lighting gel inside the cover. These
lights were also supplied by B&Q. A fused master switch was fitted to cut electricity throughout the
observatory as was the spur from the fuse box in the house. A double power socket was fitted to a rear
corner post and a key-code intruder alarm with battery backup.
The spur was taken to the pier runs straight into a metal cased RCD double socket. The PSU
for the Meade telescope is permanently plugged into one of the sockets. The plug for this is a surge
protector plug which will also protect other devices plugged into adjacent sockets. The other RCD
protected socket is used for a 4-way gang, each socket switched and lit. This wasn't easy to find. This
supplies power to the battery charger and other items used at the telescope. It was important to supply
electricity straight to the pier. It does away with trailing wires on the floor in the dark when
observing. In the image below you can see the pier with the RCD and gang mounted to a piece of plastic and
temporarily held in place.
Floor fitted
On top of the plastic membrane I lay an old carpet fitted with a foam underlay. This evens
out any surface roughness and undulations in the concrete. Then on top of this I lay the flooring which is
22mm thick chipboard flooring. This is the right height to make it level with the top of the base rail and
door step. Anything higher will present problems around the door and door guides. Grooves were cut
underneath some sections to accommodate the electricity cables where necessary. Best to make a pattern on
paper and use a jigsaw for cutting the boards around the pier. Remember what I said about the pier
concrete being lower than the pad concrete. Now you can see that with the flooring laid over it, no
vibrations from walking on the floor can be transmitted to the pier. And none are, I never get vibrations
in the eyepiece when others are moving about in the observatory. This is vital for astrophotography where
such vibrations will ruin a photograph. Seems odd, but walking on concrete will send vibrations
into the pier and scope if the two aren't isolated.
As the flooring all slots together it forms a solid, heavy, and stable floor on to which
carpet can be laid. The edges were sealed down to the top surface of the shed base rail (now level with
the floor) with tape. This effectively seals the underneath of the floor off from the rest of the
observatory. This provides a nice appearance but more importantly it is not cold on the feet! Many of you
will know the discomfort of standing on bare concrete for hours in the winter, it seemingly sucking out
all the heat in your feet.
Carpet fitted
I wrapped and glued a piece of the same carpet around the pier. Looks neat doesn't it? I
fitted brass sash handles on the roof frame front and back to pull it into position.
Apart from the doors that's the inside finished. I did have to seal around the base of the
wall panels on the outside (as well as the base rail) and water does seep under them and into wells on the
wall side of the base rail - not into the observatory though. Worms get in here (yes, worms!) and woodlice
and ear-wigs, so it was also necessary for this reason. You might think at this stage that I'm a bit
paranoid about the mini-beasts aspect but you don't want spiders in the optics and ear-wig poo is a
nuisance! You can't nor do you want to seal up the place entirely but I've done the tops and bottoms of
the walls. The eaves are open and so the roof is ventilated here. It's all a compromise really.
Telescope mounted
It was a glorious day when I moved the telescope in - a Meade
LX200 f/10 10" Schmidt-Cassegrain. To be honest there were times where I thought I'd never get that
far. You can see the scope set up in the above picture with its dew/light shield on fitted with a Kendrick
heater and plugged in to the power station battery (a lovely device, it has 3, 6, and 9V outlets and two
12V car sockets) on the floor. The pier's top plate is installed sitting on the large stainless steel set
screws. You can just see two of them coming up through the pier plate. On top of this is the telescope.
Around the telescope and resting on the top plate is a MDF board covered in black felt with L-shaped
plastic extrusions stuck to the edge (covered in black sticky-back plastic) which makes a nice lip to hang
the telescope handset on and also to stop eyepieces falling off. The telescope does not sit on this, a
hole is cut in it so it sits around the telescope. This is important because when I had this tray attached
to the tripod the telescope did sit on it and this caused large movements at the eyepiece whenever I
touched the tray.
The telescope PSU sits between the two mounting plates and runs up through a small hole in
the accessories tray to the telescope's power socket. The finder has a dew shield made from a plastic
container (large ASDA vitamins actually) which is lined with black felt on the inside and black
sticky-back plastic on the outside. Fits tightly and works well. Shame about the other end fogging up :-)
I have a variable height counter stool to use at the scope (shown below on the left), a small camping table for the eyepieces and oddments boxes, and a
table and chair to work at (not shown). I found a nice storage unit on wheels which has several drawers
for other storage and a nice flat surface to put a laptop on next to the scope.
Telescope cover
The telescope is covered with a cotton bag made from old sheets and two survival blankets
taped together with aluminium tape to make a water-proof and heat-proof bag. This will help keep the
telescope cooler in the summer I hope. I seal it up with a belt around the middle just underneath the pier
plate and a large tub of silica gel (try asking nicely at GeeJay
Chemicals Ltd for bulk quantities of self-indicating silica gel pellets and at a good price) is placed
on the accessories tray which is changed every week.
After I'd used my observatory a few times I realised that condensation is a problem. It
sometimes forms on the inside of the roof when the roof is pushed back and exposed underneath. I had
planned to fix this by gluing some large polystyrene insulation panels to the roof panels. However, I
haven't bothered yet. The walls also get condensation on them sometimes when exposed to the sky - but so
does everything else, that's the nature of the sport! This isn't really a problem but I do wipe them down
quickly with an old towel if it looks bad enough to bead and run. But if it's a light covering of
condensation, I leave it alone. It's gone in the morning.
If you also have a Meade telescope then look no further than MAPUG-Astronomy for the best advice any where on all
matters relating to Meade telescopes, observatories, piers, modifications, observation lists and lots
more. The MAPUG Mailing List helped me more than any other resource available. It is now no longer
available but the best bits are archived at the MAPUG-Astronomy Topical Archive
site.
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