Observatory Build [Archived from astronomyshed.co.uk]

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Re: Observatory Build [Archived from astronomyshed.co.uk]

#11

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A little more progress today - hampered by the cat coming home at lunchtime with a whopping chunk of rat poison in it's mouth (the cat is currently living it up at the vets, it's going to be OK, but expensive...).

Anyway, I managed to get the framework for the roof finished and the shiplap on each gable end of the sliding section. Here's the roof rolled into the 'off' position.

Image

Here's a closer view of the way that the bottom edge of the shiplap on the sliding roof will overlap the top of the sides, meaning that the weather can't get it (ok, the breeze can, but that's just good ventilation!)

Image

Next up will be to get the OSB panels for the roof cut down to size and edged along the sloping and bottom sides - then when I get a clear day and some time to spare it will be fix them on the roof frame and on with the felt. I'm going to fix the felt with adhesive - a bit like this stuff http://www.screwfix.com/p/cementone-fel ... 5ltr/41499 - which I've never tried before, but apparently it makes for a more robust covering than nailing.

cheers,

Robin
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Re: Observatory Build [Archived from astronomyshed.co.uk]

#12

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Hodge wrote:Hi Robin,

I've used the felt adhesive, works well but two bits of advice:

1. Keep it warm or you'll need a trowel instead of a brush.
2.Wear disposable clothes!
Now that is good advice :)

I'd already figured it was going to be a messy job, but the idea of having to warm the adhesive hadn't occurred to me. I'll bring the pot in from the garage to warm, and when SWMBO asks 'how long is that going to be in the house' I can tell her that it'll be gone once I get a chance to put the felt on the roof ;)

cheers,

Robin
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Re: Observatory Build [Archived from astronomyshed.co.uk]

#13

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Not had much time to build recently, but did find a couple of hours this weekend to make some progress with the roof - got the OSB panels for the roof cut to size, edged and test fitted on the roof frame.

Image

One thing I've had trouble with when building sheds before is getting the roof panels fixed in place - particularly if you don't have a helper... You get them slid up into place and go to screw one side down and the other side invariably slips a bit and you can't get enough leverage to push it back up without getting down of the ladder and then the other side slips and.... You get the picture :) This time I've attached a couple of 10cm by 5cm by 2cm blocks of wood to the underside of each roof panel, placed so that they hook over one of the roof cross beams. I just had to lift the panels up drop these over the cross beam and that panel isn't sliding anywhere any more :)

Now all I need is a dry day with nothing else planned - and preferably SWMBO and the kids elsewhere - to get the roof fixed on and the felt down :)

Robin
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Re: Observatory Build [Archived from astronomyshed.co.uk]

#14

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Tony,

yes, the tracks/wheels are definitely the way to go - all it takes is one finger to slide the roof - you'd never get that sort of smooth running from nylon wheels on a wooden track or similar.

It rolls so easily that I have had to put a couple of screws in to hold it in place for now - otherwise it would be rolling up and down in the wind. I just have to remember to take these out *before* I fix on the roof panels since they need to be unscrewed from above.... Otherwise I'll be cutting them with a hacksaw! I've got some over-center catches to hold the roof down when it's finished, but I figured no point in exposing them to the elements just now - put them on once the roof at least keeps the rain off.

cheers,

RObin
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Re: Observatory Build [Archived from astronomyshed.co.uk]

#15

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Yesterday wasn't too bad weather wise in Oxfordshire (a bit windy, but that was all), so I took a day off to get the roof on the observatory. It was quite a long job, so a good thing that SWMBO and the kids weren't around :)

Image

As you can see, I haven't finished edging the felt all round yet, but it's well enough secured to do the job of keeping the rain off.

I used the bitumen adhesive for sticking down the felt, which was indeed a pretty messy task. A small (5") gloss roller sleeve on a long handle worked pretty well for spreading the stuff around though and gave me a good reach. I'm not sure if I'd try this approach again on a pitched roof though, since the top strip of felt which has to overlap on both sides was awkward to do. I also should have applied the adhesive thicker near the edges of the roof, since when you bend the felt down over the edge it tends to lift away on top - ah well, live and learn - I'm certainly not peeling it all off and trying again!

Next step (aside from finishing the felt edging) will be to build a mock up of the way the frame, shiplap and hinges will be for the fold down flaps. I *think* that if I get the positioning right I can have the flaps fold down a full 180 degrees and keep the overlap between the two bits of shiplap each side of the hinges, but I'm going to build it up out of bits of scrap timber to test before I start on the real thing :)

cheers,

Robin
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Re: Observatory Build [Archived from astronomyshed.co.uk]

#16

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Right... another weekend, another small chunk of progress :)

The roof is pretty much done now - all tidied off round the edges and smartened up.

Image

Very pleased with that - still rolls (just about) with one finger of pressure - obviously with the boards and felt on it's considerably heavier than just the frame was, so doesn't roll quite as freely. It's not stiff or jerky, it rolls smoothly - just that there is more momentum to overcome!

I've also built the prototype for the fold down flap - just to make sure that the hinge mechanism will actually work with the shiplap still overlapping.
Here you can see it in the 'up' position :

Image

You can see that the pivot point of the hinge extends just beyond the front face of the shiplap boards.
Here with the flap folded down a bit - I had to take a little off the top back edge of the lower piece of shiplap to allow space for the upper frame to clear as it rotates over - not much needed taking off though.

Image

And finally in the folded down position. You can see how the hinges have to be set well forward to get the right pivot point in this shot.

Image

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Re: Observatory Build [Archived from astronomyshed.co.uk]

#17

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More progress today - I have finally got the hinges fixed so that the side flaps can fold down!

Here's a shot showing the second flap being fixed in place. I've temporarily fixed a couple of bits of scrap timber as supports for the flap to hang on (in its folded down position) while I get the hinges positioned exactly right and screwed in place.

Image

Next, the final result - both sides in the folded down position (with a guest appearance by Morse, the observatory cat!)

Image

You can see that there's a simple bolt at the far end of each flap to hold that end in place when it is in the up position. Where the two flaps meet, I have used another over-center catch on a diagonal to hold the two firmly together. Again graced by the cat :)

Image

The last job of the day was to put together an automatic roof safety interlock device (Mark 1), which stops the roof from accidentally rolling back into empty space when the side flap is folded down. Could do with some more work to make it more elegant, but it will do for now.

Image

I now have four complicated bits of Shiplap to put on (need cut outs to go round the hinges) and after that the cladding should go up fairly quickly. Got to build a door at some point too!

cheers,

Robin
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Re: Observatory Build [Archived from astronomyshed.co.uk]

#18

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Managed to get the cladding on the third side today, so that just leaves the door, the cladding on the door side and the floor to go!

Here's the observatory from the garden side showing the two drop down sides pretty much finished (I need a half width strip of shiplap along the top of each - waiting until I am ready to do all the bits that need a longitudinal cut before getting the circular saw out).

Image

And a view into the observatory showing the still incomplete door side and the 3rd side cladding in place

Image

I have to wait for a dry day or two to dry the deck boards out - then I can fill the small gap under the door side frame with silicone to make sure water doesn't get in that way when it's finished. Might be waiting a while for that :(

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Re: Observatory Build [Archived from astronomyshed.co.uk]

#19

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Right, an overdue update - got the shiplap on the door side last weekend and it's looking good :)

Image

I still need to cut a couple of half width strips to go at the top of the two visible sides but the gaps there aren't big enough to be a real problem at the moment - the rain doesn't get in through them.

I do have a couple of minor leaks to deal with, sadly. The rain gets in at the corners in the gap between the ends of the shiplap and the upright corner bead - I think I need to whip the beads off and run some silicone sealant down the corner between the ends of the shiplap and the face of the framing, that should keep it out.

I'm also really regretting keeping that little step of decking outside the door as the rain comes off the roof onto it and then finds its way along the decking grooves under the wall. I've got most of the gaps sealed successfully now and bought some mini guttering at Wickes today to reduce the amount of water falling on it, but I'd have been better off without it.

Hoping to get power out next (just a very long extension lead to avoid needing part P certified electrics) and then get the floor boards down. I have some 18mm OSB for the floor which will sit on battens on the decking boards.

cheers,

Robin
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Re: Observatory Build [Archived from astronomyshed.co.uk]

#20

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Nearly there at last :)

This weekend I've managed to get the OSB boards down to make the floor, increased security by putting a 5 lever deadlock on (in addition to 2 padlocks) and have finally got a mount and scope sitting on top of the pillar. Next clear night I should be able to get the polar alignment set up properly and then actually do some observing/imaging!

Here you can see the channel I've left between the decking sub floor and the boards to allow cables to run between the side (where the PC will be) and the mount without causing a trip hazard. The board leaning up against the wall on the left covers the channel nicely.

Image

I really should have got the far OSB board in place with the writing downwards, but by the time I thought of that I'd already cut a notch out of it to fit round the pier, so not worth changing.

I haven't put any networking in to the obsy yet - I can get a decent WiFi signal out there so I will try that first as it requires no extra outlay. If that isn't good enough then I can try a powerline net adaptor either in the obsy itself plugged into the power extension cable or in the house with a CAT5E cable running out to the obsy.

I've also put some mini guttering along the front side of the obsy above the door (don't seem to have a photo of this to hand) which has helped keep the step a bit drier as the rain from the roof no longer pours onto it.

Image

And there you go - probably the most over-mounted Celestron ST102 in the world - pretty close to balanced on the mount and ready to go. Will get the SE8 out there in due course but I figured the short focal length of the ST102 will be more forgiving as I learn my way round the proper use of the mount, etc.

cheers,

Robin
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