Editor's Note:  This article by Doug Crenshaw originally appeared in February of 2004.  As part of our site redesign, we will be featuring some of our most popular member-submitted articles.  These articles will be permanently available from our Member Articles section.

For a long time I have wanted an observatory. There are several good reasons to have one. It gives you a place to store all your astronomical gear in one place. You can leave things ready to go in a moments notice, thus giving you more opportunity to observe. It can also block the wind. More importantly, it can block out offensive lighting. After finding a website idea from Stellar Technologies, I decided the time had come.

This Roll-off uses your average sheet metal garden shed, and I believe can be adapted to any size made. Here is a link to the original idea. http://www.stellar-international.com/stiobs.html I used an 8 by 7 model that I found on the Arrow website. It was a discontinued model, but it's color scheme matched my existing outbuildings, which made my wife happier about the idea!

I have a 10" Dob for the moment, with a Discovery 12.5" PDHQ on the way. I decided against trying to build a pier for the time being, but there is provision for it in the frame of the floor. The floor is just 2 by 6's and 3/4" plywood, very simple so far. Here is the deck assembled and painted. It is sized to fit the base of the shed exactly, with no overlap.

Next I erected the base and the walls per the assembly instructions. It is much easier to do this help ! And don't try it on a windy day.

I attached the base onto the deck with drywall screws.

Here is the framing that will support the roll-off roof. This is all 2 by 4 construction, except for the posts of course, which are 4 by 4's. I painted everything before I put it together, and by a piece of the shed to Ace Hardware they computer matched the paint to it, which gives it nice look I think. The frame is just slightly larger than the actual top of the walls, later pictures give you a better view.

Here is the frame for the roof, upside down, with the castor's mounted. This is the exact same size as the frame mounted to the shed itself, with the exception of the rails extended out to the side of course.

And flipped right-side up, ribs and gables mounted and screwed together. I centered it carefully before screwing it down to the frame.

Here is the completed roof assembly. Along the edges are screw holes where you would normally attach it to angled pieces inside the shed. I used some standard zinc plated screws to attach it the 2 by 4 instead. On all the screws on the roof I used little plastic washers that came with the shed to insure no leaks. Also, there is weather stripping under the center ridge.

Here is the roof up! I hope you can see I mounted aluminum angle pieces in order to make a guide. Hard to see in this picture, but they are there.

I found in my zeal to have close tolerances, it's a little too tight to roll easily. I may have to make an adjustment if it doesn't loosen up with use. Here is another view, which give a better picture of the aluminum pieces.

Here it is basically completed. I have added some pieces of wood baseboard as weather-stripping. I have also caulked along every place that looked like it needed it, specifically where the shed meets the 2 by 4 framing on both the roof and the shed itself, and where some of pieces come together.

Here is a detail shot of an area that will need some weather-stripping.

And a couple more of other areas. If anyone needs a picture of something specific, Email me and I'll try to get one for you. Also if you have questions feel free to ask them.

I cannot tell you how much nicer it is to have this completed. The ability to step out and roll the roof back and start observing within minutes is a real joy. Yes, I have lost a bit of my horizon due to wall height, but I have a pretty nasty tree line, so it's not that much. An SCT on a pier would suffer less. The total cost of my Roll-Off was less than 600.00. Not that much considering what we pay for our scopes ! And well worth it in viewing pleasure.

Clear skies!

Doug Crenshaw