Editors Notes: When time permits you will be able to see the full photo progression of Dave's observatory on our gallery site.
The Construction of a Dream
by Dave Heard
In my mid teens, life got much more interesting than the stars, so all of my astronomy stuff was put in shortage for another time.
Fast forward many years to the early ‘90's when life allowed the time & I got re-interested in the hobby again. I got started, studying all the new technology that had evolved since the early 70's & eventually getting restarted with a home built 16" Dob (unheard of back in the 70's!!!).
After 10+ years of hauling this 16" around to dark skies in a trailer, I finally fulfilled another old dream & built a home way out in the country, with the intent of building my dream observatory near-by.
Building a new home & getting the place set up had put the observatory project on a way-back burner. My wife, Amy, shamed me into finally starting construction on my long held dream–my own observatory. I still had my stuff stored for decades left over from the late ‘60's that I had intended on putting into my future observatory, as well as the newer equipment & 16". The time had finally come.
First, a little about my idea for the observatory. It will be about 30' long and 18' wide in order to accommodate both my 8" equatorial reflector and my newer 16" Dob. Provisions were made in the size to be able to up-grade the main telescope to something larger–like a 25"! The construction is a pier & beam, to eliminate the cost of a concrete pad and the day-time heat build-up associated. The pier’s are rail road ties, which are not only already treated and cheaper than a commercial 6 X 8, but massively overkill for strength. The roof will roll off the main building to the north except for the last 5' of the building; this part will overhand & protect my library and record storage. The walls are about 5' high, allowing viewing with the main telescope down to about 25 degrees of the horizon.
I really had no main plan or blue prints to follow. I had many ideas from observatories that I have seen built by amateurs featured in magazines from the past 20+ years, but no real plan. I would end up figuring out what to do when I got to that part. Not that I’m that good; I just really didn’t know better!
Amy & I started construction late 2007; fortunately, the winter was mild and we were able to so some construction before the cold set in. The observatory was laid out in early August. I augured the pier holes 3' deep on the first of November; Amy & I mixed and poured about 4800lbs of concrete in early December to set the piers. The ground being so hard, the auger bit drifted quite a bit, so the piers are somewhat cattywhampous (not square). We even had to break out one pier and re-set it. (not the least bit fun) We also poured 1700lbs of concrete for a 3X3 pad for the 16" (or 25") to sit on & be isolated from the floor. And so it sat until the middle of June, 2008, because of time/money shortages. So now we have what looks like ‘Wood Hinge’ on the Panhandle Plains.
In mid June, Amy & I started building the flooring joist, about a foot off the ground. This took me two months because of funds and time–and it’s a real *%x#@+ to get the floor level when one hasn’t the faintest idea what they are doing!!! Once I got the flooring joist in place & somewhat level, the floor only took me three days to lay in. I also had to seal the telescope piers/pad-to-floor gap with a foam sealant to isolate against floor vibrations. Now it’s the first part of September, and winter is coming soon, again!
Now comes the really difficult part, as I understand it–the roof track. Everything has to be extremely level, straight, and square, especially for a roof this size, in order to be able to be rolled off by hand. So it took me over two weeks to put the double 2 X 8 treated beams on top of the piers and get them right. What I wound up with was trying to get NASA accuracy out of warped boards! Now you tell me, is this smart? But I managed to get everything level to within 1/2"; or so--not bad! I can make up this difference when I install the angle iron track (V shaped castors).
Well, then again, maybe not. This has proved a lot more difficult to do than when I envisioned it while sitting next to the building drinking a beer. And another.
Trying to space the track to get everything level proved rather frustrating, to say the least! What I ended up with is a track looking like a mild roller coaster. What I decided to do is to smooth out the track the best I can with spacers and let’s just try the roof and see if it will work. The track is parallel within a few fractions of an inch, so that shouldn’t pose a problem. It’s just the gently rolling hills and dells of the track that might pose a problem.
So, folks, after finally figuring out how to anchor the track (Attack Plan ‘M’), it’s time to order the roof trusses and get some real carpenter help to get the roof up. But first, I have to build a roof footing frame for the track casters & rafters. After this, I am completely out of ideas and construction knowledge. This is such a mess!! You will note that I am working on this building and ignoring hunting season and star partying. Awwww, but next summer......
First I had to build the footing (frame) with the castors to attach the roof trusses to. I got started on this in early November, 08.
The footing is composed of treated 2x8's spliced together for the 30' length; treated wood was used because it is straighter & much less prone to warping in the future, throwing the castors off. I also attached 2x4's to the bottom of the footing length, forming a ‘C’ channel shape, for strength. The whole idea on the roof is to over-build it strong in the first place because I can’t come back later & rebuild it stronger, but it has to be light enough for the roof to be rolled back by hand. It was figured that 5, 6" castors on each side would be enough to support the weight, so these were spaced out & attached to the underside of the footing.
Now the REAL fun–getting the footing on the rails! This was done with Amy & me with four other drafted friends. I was asked just how I intended on doing this task & I replied that I really didn’t know BUT, I had ‘A PLAN’–this really scared everyone!! Getting started, we picked up the footings (weight: 180lbs), carried them from the garage construction site to the observatory, then gently lifted them into place on the tracks. I then had the forced help hold the footings in place & level while I attached long 2x4's between them to keep them in place & level. This done, I just HAD to test my roof rolling idea! The framework seemed to roll all the way off with no problems, but was obviously unstable. I anchored the frame with rope to keep it from rolling around (the high wind eventually did break the rope & about 1/3 of the frame did roll off the track–I was able to lift the frame back on & repair the minor damage. Now, heaver rope & wire!)
Next came the rafters (roof trusses). I checked with a local contractor on building 7 roof trusses & the price came out to over $700! WELL, I can do the same thing for less!? I used the contractors engineering design for my design & Amy & I got busy one weekend sawing & nailing (we actually used screws, but that didn’t fit in well here). The pitch ended up being a 3.6:12 to prevent wind overloading but allow snow to slide off. We finished that weekend & started installing the trusses the weekend before Thanksgiving. I tried to enlist the help of friends, but everyone was busy; so I decided that Amy, my son Jackson, & I could get them all up & anchored. Amy asked me how we were going to do this & I just answered with the dumb look–how should I know!! We managed to get the rafters up &, with Amy holding them level, I got them anchored to the footing. I then added the pearling & X-patterned the bottom of the rafters to prevent horizontal sheer.
The next step was to build a framework around the building piers for the sheet metal ‘skin’. Fortunately, we had a very mild winter, as I didn’t get started on this until the first part of December, 08, & didn’t get finished until a month later, because of constant re-do’s.
Building the framework proved to be quite a problem as now I discovered that the building wasn’t really square with the roof rails; the roof REALLY does need to roll off square to the sides because fo the roof skirting. WHAT A MESS!!! I did finally figure out how to square the framework with the roof.
I had a roofing company come over & install the sheet metal skin because this is really something that I had never done & I wanted professionals to do it so that it was as weather tight as possible. This was finished in early February, 09, & cost about $6,200. Of course, I just HAD to test out the rolling roof–it still worked, although now the added weight (1750 lbs. total) made it necessary for both Amy & I to open it together.
After getting the skin on & putting a tarp over the door way, we waited out winter, starting construction & installation of the double doors in early March, 09.
With the doors on, it was now time to finish up the inside. I installed a series of bookcases against the north wall for my library. A wall with an attached desk was erected to separate the library from the observing floor. This done, I painted the interior a flat black to help prevent stray light.
While all of this was going on, I was trying to figure out how to open up the roof by myself. I could just envision some night Amy helping me roll back the roof, then later getting tired & going on to bed–she wouldn’t be too pleased with me waking her up to help close up the observatory. I tried a series of rope block & tackle; this worked, but proved to cumbersome. I finally settled on an acceptable solution: I anchored an ATV winch to the south end on a pier (rail road tie) & ran an extension cable through a pulley anchored at the other end. Now, I use the winch to pull the roof open, then by switching anchor points on the roof, the winch pulls the roof closed.
After a trial run in June 09 to test out collimation & the new Sky Commander on the 16" and polar aligning the 8", I was now up & ready to go.
Currently, this is the largest observatory in the Texas Panhandle that I know of, though not the only observatory. And there are much larger telescopes in this area.
All in all, it’s been real exciting building an observatory that I have wanted since junior high school. At times, it was actually very frustrating and quite madding, trying to figure out the technical problems that I encountered. It was really fun to watch this thing grow from nothing to functional, being able to see what I had accomplished/screwed up at the end of a work day. Amy was the driving force behind me to keep me focused & giving a hand in construction with both good advice & excellent labor. It took me 18 months to build, with me doing all of the construction except for the sheet metal, and cost about $12,500. Now, if I ever move & build another one, I’m going to get a DOME!!!
Amarillo Astronomy Club