The Cat House Observatory
Home Equipment Observing My Observatory Images Links Projects Bitz & Bobz Mail Me
25/09/06
An unexpected bonus! Since the wife removed her fat cosseted cats from their luxury home in our shed, I've been pestering her to pass it on to me. (I get all the cats' hand-me-downs if I behave myself...)
To my surprise, several weeks ago she agreed to let me store my scope in there which I duly did. Of course, if you've got an 8 x 6 shed with a scope in, it's a shame not to use it as an observatory isn't it? My idea didn't go down well however as she didn't want me moving the shed now she's got the garden straight (fair enough I suppose). The conifers in the pic are to the west and south and overhang the shed by about 3 feet so the current position is not fantastic.
We finally agreed that I'd move the shed out from the conifers by a couple of feet and cut them right back to give a worthwhile outlook to the south and east, and an unimpeded upward view but no outlook to the west. On the basis that everything in the west was in the east / south a while ago, this should work fine.
I'll be moving the shed in one piece, and I'll be using the simplest roof design I can come up with to ensure it's ready for this winter, my 1st since buying my scope. Also, the fact that the shed is already assembled means that I'll have to think about how to construct a pier with the shed already in position...
The shed in it's original position
28/09/06
Project underway! Today I Laid some extra flags and carefully slid the observatory into its new position, and designed the sliding roof. Hopefully I'll modify the roof early next month
The "observatory" in it's new position
02/10/06
Rip it to bits & have a look. A cracking good few hours work while the wife was on her way back from doing the Great North Run. I bought all my timber, removed the roof, made the necessary mods to each section, and raised each gable by a couple of inches to allow (hopefully) smoother sliding. This is the first time I've been able to stand in my future observing position with the roof removed and check out the views. I'm really pleased by the amount of sky I can see, and I'm now more motivated than ever to get the Cat House Observatory commissioned!!
Why does it always rain when you've just removed a roof?
07/10/06
The rain has finally stopped and I've managed a further two days of work -
Sliding rails on the shed gables. Originally I was going to use removable legs to support the roof when open but this proved less than satisfactory as the roof sections are quite cumbersome and easily dropped, potentially causing damage / injury etc. I used 50mm square timber for the rails, and they will eventually have 50mm square permanent legs
Roof modified and refitted. I fitted timber runners on each roof section which sit on the rails to allow the roof to slide. This was ok but the sliding action was quite sticky and required a step ladder and a lot of huffing and puffing. Not great at 2 o'clock in the morning. To improve things I screwed three PTFE furniture sliders to each runner, added some diagonal bracing to make the shed more rigid and fitted a counterweight system using rope, pulleys and 5ltr containers full of water. The sections now slide open almost by themselves when the clamps are removed and close easily and smoothly using just one hand. Excellent!
Clamping & weatherproofing. I secured each roof section using four turnbuckles to clamp it to the shed framework. A further three turnbuckles clamp the 2 roof sections together under the ridge. This means that there are eleven turnbuckles to remove before opening the roof but it only takes five minutes and the piece of mind in high winds will be well worth that small inconvenience. Designing a satisfactory weatherproof ridge piece which doesn't impede the movement of the roof proved difficult. So far I've simply attached lengths of foam rubber copper pipe lagging to the ridge of one section, and once the sections are clamped together this forms an excellent seal. The foam does not soak up any water and it has not let one drop of water through despite several showers so far, although I would hesitate to leave my scope & computer in there in heavy rain at this early stage. Time will tell...
A couple of pics showing the sliding roof, rails, counterweight system and experimental ridge sealing system.
31/10/06
Hmm. After a good downpour recently there was evidence of water ingress. I found that water was seeping through a joint in the lengths of pipe lagging (The rest of the seal proved faultless). Whilst this would be easy to sort, I don't want to risk getting my scope / PC etc soaked so I decided on a different, and altogether better approach. I planed two batons at an angle to fix on the ridge (one for each roof section) which when brought together give a horizontal surface about 3" wide across the ridge. I mounted a piece of T section rubber to one roof section which covers the batons and also seals the gap between the two sections. Hopefully this will be a vast improvement over the dodgy mark 1 bodge... Update - No it's not! Aw heck. We've had some rain lately and it's constantly dripping in. I've reverted to the original system with some mods and so far it's excellent even after a huge downpour with high winds. Update - still watertight after 3 winter months
23/11/06
Today at last I started the pier. Firstly I jig sawed a piece of the shed floor out to make a hatch through to the ground below, then I dug as big a hole as I could but the size was limited to the gaps between the floor joists & bearers allowing a hole of about 20 inches by 14 inches. I dug down 24 inches which is 30 inches below the shed floor. I concreted a length of 110mm plastic drain into the hole to form the pier and filled that with concrete as well apart from the top 250mm into which the top section will slide. To provide extra rigidity I ran a thick walled steel pipe up the centre of the pier. It took 175kgs of concrete to backfill the hole so hopefully this will provide enough ballast. I drilled some 2 inch holes in the underground section of the pier to allow the concrete inside and outside to bond together.
Update - 3 days later the concrete has set and the pier is rock solid. I'm very pleased with it's rigidity
30/11/06 - 05/12/06
Another few sessions on the pier. Over the last few days I designed (yeah right...) and made my pier's top section using a plastic 170mm - 110mm reducer to increase the diameter at the top of the pier to 170mm. This matches the diameter of my top plate. The 110mm end is a nice tight fit inside the main section of the pier. I filled the top section with concrete and concreted in the 4 studs which will take the top plate. I made the top plate from a 170mm diameter steel pipe flange with a piece of steel tube welded onto it to take the GP pillar adapter. The pier's top section is removable and is held in place using 2 Mikalor heavy duty pipe clamps. It will rotate through 360 degrees which allows initial adjustments to Polar alignment to be made by rotating the entire top section so I can get it fairly close without using up all of the adjustment on the GP mount. As usual now it's all in place I realise I could have made a better job by designing it differently so this is very much the Mk 1 version and the top section will be replaced when I get around to it.
22/12/06
First Light!! Wow! I got me an observatory and it works!! What an improvement. From sitting in the chair thinking "I wonder if the sky's clear" to observing in 10 minutes flat. 5 minutes if I don't have to change clothes first...
18/01/07
Getting geared up. I've had several evenings in the observatory now and it's time for some fine tuning. Over the past couple of days, I've powered up the observatory, installed a PC and started experimenting (on terrestrial targets) with my new Toucam Pro. I've also painted the obs matt black inside to make things a little darker.
04/02/07. Although my obs will probably never be finished as I'll always want to alter various things, I've now got everything installed and last night I took my 1st succesful images. A small step for Mankind but a humungous leap for this man!!
The finished article!
4 months in the making and I'm very pleased with the outcome
