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The large junction box with a removable back was used
inside and outside, making it easier to pull any future wires through. This is not as easy as it seems, due to the distances,
angles and number if wires. We used two network catagory 6 wires (color coded), 1 telephone wire, one low voltage wire
and one coaxial cable. In our case all wires (except the telephone wire) were duplicated in case of failure. This
amounts to a large jumble of wires which can be difficult to feed; as will be seen.
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The "Simplified Floor Plan" may be a bit difficult
to read and can be downloaded to better view. The SkyShed will be (at least) 12 x 16 feet with two basic telescopes
as shown (both with piggy back 4" refractors). We're considering increasing the size to 14 x 17 ft (to allow for
a little more room during star parties). The power to the SkyShed will be controllable from the remote site using "Smart
Home" technology (Powerhouse X-10). The 4 individual power stations are described and will allow for local or
remote powering up of the building, individual telescopes and work stations. There should be enough room for several
people, making the observatory useful not only as a robotic observatory, but also as a teaching facility. This last
point is crucial to the purpose of the Maine Astronomical Society and is the reason I opted for a larger structure.
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Walls and Rail In Place...
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At this point, as can be seen, the basic structure,
minus the sliding roof, is up. A small deck is present in front of the structure (steps and rails will be put in place).
The rails are sturdy, are 6 x 6 in size and held in place by 6 x 6 posts which are on 4 foot deep foundations. This
is a variation from the original SkyShed design, done because of the increased size of our observatory. As I'll reiterate
again and again, I highly recommend obtaining the SkyShed design CD, or having them build the structure for you (if you're
close enough to Toronto). They've put a lot of time into their construction CD and it points out the many pitfalls
which can ruin an observatory. They've not only put alot of time into how to build the basic structure (including telescope
foundation), but have a clever and effective design for the sliding roof, the most critical part of the structure).
The company can also send you a kit with all the "hard to find" items and they even have detailed list with part numbers,
so one can go to Home Depo (or similar store) for the parts. I believe they'll have an automatic opener included in their
plans in the near future (ours is self designed with help from Brad at SkyShed and Paul Murphy, our carpenter).
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This is one of those things you never forget, and can't
believe you didn't know. The photograph of the twisted wire is, of course, the punch line. What you DON"T want
to do, when feeding long multiple wires, is what my son (Greg) and I spent three hours doing. We ran the first
25 feet from the remote observatory (in the house), and then through the attic to the point where the wires enter the conduit
(and then travel through the garage and outside to the observatory). We had 9 sets of wires still attached to their
spools at the point where they were to enter the conduit. Each wire was then taken off the spool (one big
twisted mess of wires with a curve still built into them) and the whole lot was then pulled through the conduit (trust
me, you can't easily get them through one at a time). As we did this the wires tended to spin and twist (ie, remain
in the state they were in when they came out of their spools). Despite hours of trying to 'untwist' this jumble of wires
while working in a confined attic space, we could not keep the green cat 6 wire from twisting (as can be seen, quite badly
and possibly with internal damage). Obviously the green catagory 6 wire will be used as a last resort.
Bottom line: 1) first run your wires out, untwisting them as you do, then tape them all together and run the lot as a single
"bundle" and 2) run duplicates.
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A good deal of thought went into the foundation of
the telescope (whether effective or not, time will tell). And though this picture may not be pretty, we're hoping it
will further minimize any pier movement which might occur during the winter. This is the pier just before the last two
feet were buried. The foundation of the pier begins 5 feet underground, with the sonotube sitting on the top of the foundation,
beginning 1 foot under ground. The top 2 feet (ie, the first foot of the sonotube and the top foot of the foundation)
are wrapped in 2 inch foam. The reason for this is that the top two feet is the usual depth of our winter frost line.
The hope is that by doing this we will minimize the effects that the earth along the frost line might have as it push/pulls
on the top two feet of the pier. Granted, it is unlikely that the frost line would cause much movement as the foundation
is 5 feet deep and further secured by rebar pounded 2 further feet into the gound (ie, total depth of 7 feet). But considering
my previous experience (the telescope on a deck) I figure its better to be a little overly careful. John Smith, our consultant,
sitting in his 70 degree Arizona winter weather, got us going with this as he was concerned about potential effects of the
frost line (do they even have frost in Arizona ??).
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Wiring All Run Underground and Under the Floor...
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The computer lines (3" sonotubes; just in case I have
to run a parallel connector) and the electrical lines (1") all run underground to the house and then under the floor.
In the far corner three 3" conduits can be seen (circled in red). The one on the left will carry all the
computer/low voltage wires into the structure from the house (which contains the 'office' which is the remote observatory
from which everything can be operated) and the other two 3" conduits go to the RC-16 scope and the LX-200.
The computer lines and the electrical lines to the RC-16 can be seen in the foreground, with the red circles around them.
Neither touches the sonotube and, as usual, the electrical and computer lines will enter the scope from oposite sides of the
sonotube.
Also note the 2 x 6 construction. This differs somewhat from the Sky
Shed design, and was done because of the large size of the structure (not to mention the fact that we frequently get hit by
40 - 60 mph winds from Mt Washington, which still holds the record for the worst weater conditions in the continental United
States). SkyShed's, which use 2x4's, have been hit by major blizzards and have evidently all have held
up well (we still like the 6x6 design in view of the size of our observatory). Our walls and floor are of a composite
(weather proof) materail and painted clapboard (to match our home) will be placed over this. The ability to use the
SkyShed CD plans for many ideas and yet vary from the design is another one of its many strengths. In our case the size
and weather conditions prompted us to make modifications, including 4' deep pilings for the structure and rails and 2x6 walls
with a 6x6 rail. This has added significantly to the price. For any structure 14x12' or less, I'm confident that
the SkyShed design, as it comes on their CD, will do the job well and be much less expensive to build. Again, I'd strongly
recommend contacting SkyShed at www.SkyShed.com before proceding.
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It seems only right to go over the basic networking
setup and wiring diagrams. The ideas come from John Smith, and the results of this method are evident from
his impressive website. This diagram is simplified and still a bit hard to read (download to improve readability).
Basically the remote observatory can, via a desktop computer (using XP Professional) run the local observatory whereas a laptop
in the local observatory can run the show via networking (via the router) with the main computer in the remote observatory.
The USB output of the desktop computer in the remote observatory is converted and carried over Cat 6 cables and
then reconverted on the other end, either to USB or to serial (RS232), as needed (conversion in needed due to the "5
meter limit" of USB, extending it to over 100 meters if needed). The lcoal observatory will require USB for: 1)
a web camera to see the inside of the local observatory (If the roof is not fully open the RC-16 will move from its 'parked'
position and slam into the roof. This would not be a good way to start the eveing), 2) the planetary video camera (currently
using Meade's LP-1) and 3) SBIG's ST-10XME/AO for CCD imaging with the RC-16. The USB signal will be converted
to serial (RS232) for: 1) the Software Bisque Paramount ME mount (for the RC-16), 2) the TCC (RC-16 telescope control center,
including temoerature adjusting microfocusing and heating for the secondary mirror), and 3) the SBIG STV. Althought
the SBIG STV Remote Program works well, the video output is very slow using the computer (the downloads are not real time)
and therefore there will be a video link back to the remote observatory. As John has explained to me, this may seem
a bit daunting for those of us without a solid computer background, but this does simplify the setup, allowing the RC-16
to be controlled either locally (in the outdoor observatory) or from the remote observatory (ie, in my home). At star
parties, members could use the telescope using local controls; for visual, ccd or video purposes. Additionally, the
entire setup will be robotic and can be fully operated from the remote observatory (a big plus in the dead of winter).
I Keep Making it Bigger...
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I can't think of anything better to say here except
that we've gone from a 10 x 10 foot structure, to a 12 x 14 foot structure and now up the 14 x 17 foot platform you see here,
with a 3 foot wide deck on the west end. I figure the bigger the structure, the beter off we'll be at star parties (John
Smith wants to know where the billiard table will go...). The down side is the logistics. Brad at SkyShed agreed
to this size, though they usually keep the width to 12 feet (the largest 'standard' size for thier roll-off shed design).
Expect the construction to move fairly rapidly at this point.
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This photo shows the northwest corner and is important
from a structural perspective. Again the 2x6 frame and 6x6 rail can be seen. One example of the type of detail
SkyShed cares about can be exemplified by way the rail is cut over the structure itself, and not at the edge of
the structure (where, over time, an cantelever effect could significantly bend the rail and effect the roof sliding performance).
They have dozens of key points in their CD, problems they have encountered, solved and detailed, so those of use who plan
to build just one observatory can avoid. They also have a clever design for attaching the roof to the glidiers.
For those type of details I'd recommend their CD. If this recommendation isn't convincing enough I'd recommend you check
out the article detailing their "Polaris" award from the Belmont Society. This can be viewed at www.belmontnc.4dw.net/skyshedcd.htm and discuses the many merits not only of their design but also the method in which the CD displays the construction
process (slide show with rotating 3-D schematic views, detailed technical notes, etc).
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