Has anyone ever converted ....

[ZeroID (Brent)]

..one of those kitset garden sheds to an Observatory?
I have gained approval from my lovely wife to go ahead as long as I don't do anything silly, she said she knew it was going to happen eventually. Love her !! And it will get the mount\scope out of the lounge where it lives at present.

I have spotted a deal for a 1.8 x 2.7 meter with a sloping flat roof which I think could be converted to roll/slide off leaving an 500mm overhang over a work bench at one end for PC etc and the mount at the other. My question is can the roll/slide off roof be made to happen. I'll have to go and look at one when I get a chance but price is quite good for the size and it has a decent hinged door, not one of those silly slide things..

I reckon the roof assembly would be so light I could just put teflon or nylon strips along the top rail of the walls and just pull it off. I guess I am wondering how stable the walls would be although I can add some strengthening bars and corner bracing easily enough. ( Just about talked myself into it haven't I ?)

SkySlab is looking more likely every day.

[SkyViking (Rolf)]

Hi Brent, I did for my first observatory. I used to have all the pics online at a Geocities site, but since they closed it has been offline.

But voila, it turns out Google has cached the old page, here you go: http://www.geocities.ws/hwy37/observ...struction.html

There is an annoying floating menu that doesn't seem to quite work any more, but at least you can see all the pics.

[ZeroID (Brent)]

Rolf, you are a gem !! Again !!

Fundraising in earnest now, I'll have to stop buying EP's and Scopes and stuff. Although I'm looking at a 2" crayford for the little 80 mm .... . Replace the R&P 1.25" so I can load the DSLR on the end, I hope.

[ZeroID (Brent)]

Crayford is on its way shortly and 2 EP's, 6 & 9mm TMB Planetaries (Thanks Sylvain) to replace my poor quality Plossls at that range.

But with permission granted I did an exercise to measure the stabilty of my proposed Ob site on the big slab of concrete out in the garden.
At 4 m x 3.7 m and a minimum of 300 cm thick it came to nearly 5 Cu Meters of concrete. At 2200 kg per Cu M it's about 10 - 11 tonnes !! That is excluding the filled 2 high block walls on 2 sides and the fact that is is attached to the lava flow rock base under my garden on Mt Albert.

If I detect ANY vibration it will be time to run as it will mean Mt Albert will be getting ready to erupt again, most unlikely. I hope !

I am looking at likely using my 870mm long, 250mm OD sewer pipe as a pier. Drill and secure some bar into the slab with Rockite then pour cement into the pipe to lock it down. Make up a top plate etc.
I was going to start with the mount tripod but it looks easier to build a floating floor around the pipe. And gives more room inside of course.

It's all coming together ...

[SkyViking (Rolf)]

That sounds like a very stable base for your obs Brent! And I'm sure the drain pipe will be an excellent solution for your pier. I used a drain pipe myself but it was only 150mm which was the biggest I could find at the time. It turned out very stable, so 250mm diameter should be absolutely rock solid. My current pier is around 250-300mm too, it is a good size.

I was wondering, how are you installing the floating floor if you have a big slab underneath which is attached to the pier? Or will you build it larger than the slap size?

[gregbradley]

I did.

Mine was a standard colorbond garden shed with double sliding doors.
It was about 2.4 x 1.8 or something like that.

The first thing I did was to line the inside edges of the shed with 75 x35mm pine to create a timber frame on all sides.

I fixed the pine on the floor to the slab (it was on a concrete slab) with anchor bolts.

The top 2 main beams I got were 6 metres. I created a rolloff roof frame by cutting a little square in the corner of the shed and running the 6 metre beams out past the shed. I then had a couple of vertical support beams to suppor the roll off structure. I fixed a 50 x 25 batten to both sides of this roll off top beam so a roller wheel would roll on it without falling off.

So that was the frame.

The roof I added a stiffening timber underneath (it needs to be packed out to be horizontal as the roof is sloped) and rollers to that. I made it into a truss ( a triangle) otherwise the roof will collapse when rolled off.

I may have photos somewhere of the final thing.

I used latches to lock the roof down after it was shut and also to prevent it blowing off. It never blew off and it did not leak and the rolling action was very smooth and quiet as my neighbours bedroom were fairly close by.

Greg.

[[1ponders] (Paul)]

What a great job Rolf, that looks fantastic!

[SkyViking (Rolf)]

Originally Posted by [1ponders]

What a great job Rolf, that looks fantastic!

Thanks Paul. This was my old observatory, I later moved and had to do it all again
It was great fun to build though. BTW Greg's account is pretty much an exact description of what I did. Like minds I guess

Brent, I think you'll find it relatively straight forward and the issues you'll face, and their solutions, will be pretty much identical maybe with minor variations due to the design of the shed itself.

[jenchris (Jennifer)]

I'm hoping your slab is going to be 300 mm and not 300 centimetres - as it could be a really big drain on your purse.

[ZeroID (Brent)]

Originally Posted by jenchris

I'm hoping your slab is going to be 300 mm and not 300 centimetres - as it could be a really big drain on your purse.

Ooops! Yeah 300mm is more like it. That is an average guessitimate of it's depth. The ground slopes away to the south and it is cut into the other side by about 300 mm.

Greg: your instructions are excellent and echo Rolfs very well. The shed I am looking at is 2.7 x 1.8 meters. Thanks for the info.

Rolf: the slab is already there, been there for about 25 years as far as I can tell. The shed will sit on the slab, otherwise it would be huge and annoy my wife considerably not to mention cost heaps. It would also annoy the neighbours as it forms part of the back fence line. The shed will sit on beams on the slab. That is why I was checking the weight\stabilty numbers. At 10 +tonnes I very much doubt it will flex enough to make a difference and one day I might go remote. The floor will still be isolated from the pier by a gap to prevent any accidental knocks having an effect.

Heres a pic of the slab as it is at present. Overhanging tree at right is already gone. This is the south facing side. Mt Albert rises up behind to the NW. Roof will roll off in the direction of tree that is now gone.

[ZeroID (Brent)]

Been having another think on this project. The shed idea is to be self contained, all the computers, power etc out there out of my very tolerant wifes way. So part of the shed was always going to be covered by the roof so PC screens etc were out of the dew fall line.
There are also limitations by the positioning of the slab on the section and fences etc that made a RoRo roof a bit of a nuisance and they are hard to make and align so .....
I have worked out the simplest roof movement system ppossible. It only really applies to lightweight sheds but all it requires is a bolt pivot at one edge and the whole roof just pivots away 90 degrees and sits on the sheds top rails with maybe a little support to one side. Pivot point is about 700 mm up one of the longer sides of the shed and as it swings back it leaves a 700 mm overhang over the working desk area. With some simple framing that not only supports the roof but braces the walls etc I can fit the whole thing, roof swung back inside my slab area .. And the scope is actually in a better position on the slab.

I'll do a sketch and upload it, it's just too simple. Now I'm keen to get started.

[ZeroID (Brent)]

Quick sketch, no measurements so it doesn't all fit or is to scale and there would be more bracing etc but hopefully shows the idea. Roof hasa slight slope front to back, 100 mm over 1800 mm but that should not make a problem. Unlatch it from any tie-downs and just push it up slightly and swing it around.