Need Some Guidance on Siting an Observatory

[JamesF]

10 minutes ago, russellhq said:

Thanks James. I was thinking of using something like slotted shelving rails where instead of shelves it would be a screen.

If you had multiple well-spaced anchor points on both sides I reckon that might work, assuming you can find or engineer the appropriate hardware.  I think what you need to avoid is having attachment points close together and no other support because there's little resistance to the leverage applied by a sudden gust of wind.  That's why the more I think about it the more I like the "extending table" idea (which I may not have explained very well).

James

[JamesF]

16 minutes ago, Gina said:

Nah!  A piece of plywood in guide rollers and string attached to the bottom then up over a pulley to pull it up.  I'll make you a diagram if you like.  But tomorrow - I'm off to bed shortly as I've had a busy and tiring day.

I can see that working too, and in fact I was thinking on something similar myself.  You'd just want to keep the rollers and the pulley below the height of the permanent walls.  I'd probably look at something like this if I were considering automating the observatory.

James

[Adam J]

On 03/06/2018 at 22:58, Astrokev said:

Interested in this discussion as I have an horrendous decorative lantern in next doors drive just at the back of my obsy. My neighbour has kindly agreed to "blank out" the side facing my garden, but I'm worried there'll still be some stray light finding it's way into my OTA!

If he blanks it out you will be ok, nothing you have to deal with can be worse than my garden lol.

[timwetherell]

As a visual observer, I find a dome helps enormously in blocking stray light. Mine has an opening 600mm by 1000 and that enables me to track for an hour or so whilst keeping out the local streetlight. But if you're only interested in imaging, a long flocked dew cap would probably do the same job for a fraction of the cost and difficulty. Still a good idea to have the scope permanently mounted as it saves hours in set up and keeps the scope thermalisedish. Though in scotland thermalised probably has a different meaning to down here!

 

[russellhq]

Inspired by other members on the forum, I decided to give SketchUp a go and can say it was a fairly intuitve process (though some minor annoyances which a quick YouTube video sorted out).

Here's the finished observatory, it's roughly 1.5m x 1.5m x 1.5m

Next, starting from the ground and working up is the base:

Floor sheeting (OSB3)

Walls. Timber construction with 50mm polystyrene insulation

Door with insulation:

Walls with sheeting (shiplap outside, OSB inside and ply on door)

Roof frame. The idea here is the roof can be lifted up from the back and rolled off completely (hopefully not too heavy to lift back on)

The roof sheeting - going for OSB which I'll cover with felt

 

Disclaimer: I'm not a builder and I don't know what I'm doing...

[JamesF]

An excellent start

James

[Gina]

I would recommend EPDM rubber roofing rather than felt - much easier to apply and longer lasting.

[JamesF]

Yes, I'm not sure I'd go for roofing felt.  It tears easily and becomes brittle with age which might not be a great idea if you're lifting the roof on and off.  If the roof were just rolling off with less chance of getting caught on something then perhaps it would be better.

James

[russellhq]

I chose the following materials for the construction, not sure if the sizes are appropriate for the build or if I need something larger/smaller?

Internalsheeting: 9mm OSB3

Floor: 18mm OSB3

Roof sheet: 9mm OSB3

Wall frame: 38x63 treated timber

Roof frame: 45x70 treated timber

Base joists: 47x150 exterior grade timber

Door sheet: 9mm plywood

Wall cladding: 12mm shiplap

 

[russellhq]

I priced up some of the materials I'd need from a local timber merchant and this is turning into an expensive little box! I'll still need to add in £100 or so for the EPDM roof sheet.

I think I will ditch the idea of a ply sheet on the door and instead go with OSB as I'll have plenty of it.