DaveS's Obsy Build. First thoughts.

[DaveS]

Very early thoughts as yet. Looking at the house I'm in the process of buying, the garden has somewhat high horizons. If I cannot lower the hedges significantly, then perhaps I can raise the Obsy?

Looking at planning regs, if I go for a double pent roof, then provided it's more than 2m from the boundary I can build up to 4m high, which means, I think that I'd have height to put the whole thing on a concrete platform 500-600mm high. For aesthetics I'd build (Have built, more like) a stone retaining wall rather than just use shuttering. As the house is in a conservation zone, and the obsy is likely to be more than 20m from the house I'll be limited to 10 sqm, so perhaps 2.5x4m with a 2.2x3m obsy with a border for access.

I'm planning for 2 piers / mounts so I can image 2 targets at once, and there won't be a warm room as I plan semi-remote operation from the house.

I'll leave off for now, as I haven't even thought to much about construction, beyond basic stud-and-cladding, and invite any thoughts / suggestions.

[Astrokev]

Sounds interesting....?

[DaveS]

Adding to this.

Perhaps, instead of a single big concrete slab, I can cast two tall concrete blocks, maybe 1 metre into the ground and 0.5 metre above, then build the obsy with a 0.5 metre stand-off to raise the floor level to the height of the blocks. This would reduce the cost and would act as less of a heat-store. Downsides would be the increased complexity of the woodwork (I'm notoriously cack-handed), as well as providing a lair for animals, esp foxes unless I provide *very* secure sides. It would be easier to run the power and network cables under an open build, but again the animals might be a problem.

Another reason for the pitched roof is that ASA mounts default park with the dec axis horizontal and the 'scope on the east side pointing at the zenith. For my DDM60 parking this way would make the initial homefind simpler. However I hope to install a long FL 'frac so need the height above the pier, so having a pitched roof roll off along its axis makes sense (At least to me).

Sorry for not posting diagrams, got to install and learn sketchup first, and not much room on my boot drive.

[DaveS]

Just yo make it clear, this is the 'scope in the default park position

The roof would roll off along the dec axis.

[Davey-T]

Bear in mind Dave that a heavy pitched roof will need lateral support to stop it collapsing in the middle so reducing the clearance over the scope.

Dave

 

[DaveS]

Good point Dave, thanks.

This is why I've posted my first thoughts so early. Don't want to run at this like a bull at a gate only to come a cropper.

I'm thinking of a steeper pitch, something like 60 deg internal angle, so perhaps the bracing can be further up the roof?

If I only had a single pier / mount then a dome from Pulsar would be a possibility, but more expensive and not as much fun!

[Swoop1]

Could you go for a shed roof pattern with a fold down 'flap' to the high side to open up the horizon? This would reduce the bracing needed for the pitched roof?

[Adam J]

I went with a pent roof with a hatch at the tall end to allow it to slide over the scope when opened without collecting it on the way. 

[DaveS]

Those are interesting, but at some point I am thinking of automating roof opening and closing so having a fold-down flap anywhere would multiply the complexity. The pitched roof can also be higher without needing specific planning permission.

[DaveS]

Have now installed Sketchup Make and trying ideas. Learning curve? More like a mountain! 

I wonder if @RayD and @souls33k3r have any ideas? .

[JamesF]

There are lots of youtube tutorials for Sketchup that might help.  Once you get the hang of creating a few 3D shapes then it's not too bad.  I turn almost every element into a "component" because I find them easier to work with.  Some of it takes a while to become intuitive and I still do occasionally lose where I put my model but I'd say that with a couple of hours practice you can get going quite well.

James

[DaveS]

Thanks James. I have a couple of books in my Amazon basket, just got to buy them now.

This is a *very* rough first go at putting some thoughts down. No real structure as such, just a rough outline. The roof runs east-west-ish, and opens to the west, furthest from viewpoint.

The base is 2.5x4 metres by 0.5 metre high. The obsy is roughly 2.2 by 3 metres with walls 1.5 metre high. The nearside wall will be fixed up to the pitch of the roof.

I will make something more detailed as I learn Sketchup.

[Davey-T]

A roof frame welded up out of 1" square steel tube would be an easier thing to build and less bulky than timber and no heavier, also easier to fit rollers to for automation and only need small braces for strength.

Dave

Edited May 31, 2018 by Davey-T

[DaveS]

Thanks Dave, yes that makes sense. Possibly conventional wood-framed and clad walls up to the rails, then the welded steel roof.

Hopefully there should be steel fabricators in a rural area, after all farmers need barns repairing?

[Davey-T]

I can always pop down with my MIG welder when you're ready

Dave

[JamesF]

Keep at it with Sketchup, Dave.  At Kev's suggestion I picked up Sketchup again after a break of many years (and I didn't exactly push it very hard even when I was using it) and after a couple of evenings this is what I have for my latest design:

I've found that getting into the real detail of the design starts to flush out problems I'd not thought of and things that I need to know better that tend to get glossed over when I just keep the design in my head or scribble it on a bit of paper.

One of the real bonuses is that it's also far easier to decide that you want to change something because you don't have to start from scratch again, especially when you start using components.  For example, I've changed the wall height a few times, but most of the work to do that involves changing the size of one of the timbers in the wall and because the others are all duplicates they change at the same time.  Then move the top rails and remove or duplicate the extra cladding and I'm done

The really irritating thing about Sketchup is when people post screenshots and you can't pan around them to get a better look

James

James

[Astrokev]

50 minutes ago, JamesF said:

Keep at it with Sketchup, Dave.  At Kev's suggestion I picked up Sketchup again after a break of many years (and I didn't exactly push it very hard even when I was using it) and after a couple of evenings this is what I have for my latest design:

The really irritating thing about Sketchup is when people post screenshots and you can't pan around them to get a better look

James

James

Here you go ?.

In addition to the screenshot image, below is the SketchUp file of my build. Save it to your desktop then rename it by deleting the .pdf extension. The remaining .skp file will then open OK in Sketchup.

I've chosen a different approach to James (I'm not saying mine is better - just different). I prefer to make groups rather than components, but either approach works. If you try and draw complex 3D shapes without using groups (or components) they will do strange and unpredictable things when you try to move or change them.

As you'll see in my file, I've also put each different part of the build on a different layer so that I can hide bits I'm not interested in when working on the design. I've also added layers which have all the dimensions - very helpful when actually sawing timber, as I just work off printed layers to act as blueprints.

The other tip that I've found useful is to build a piece of timber "away" from the main model. Create this as a group and then move it into position in the main model. For accurate positioning, use guides and "grab" the group you're moving by a corner rather than a face. Once you practice this, creating and moving pieces around is very simple and good fun.

Hope this helps.

Kev

This model is an accurate dimensioned model of the actual build in my ROR thread. I'm still working on the rolling roof, hence the reason I've coloured it sickly green.

PS The whole green roof is a group and can be "rolled" over the warm room to help me check dimensions etc.

 

Final Design mod 4 -SGL.skp.pdf

Edited May 31, 2018 by Astrokev

[JamesF]

Blimey Kev, that's seriously fancy.  Clearly you are far more skilled with it than I am :-D

James

[Astrokev]

5 minutes ago, JamesF said:

Blimey Kev, that's seriously fancy.  Clearly you are far more skilled with it than I am ?

James

I doubt that!  Layers are really easy. As you mentioned earlier, there's loads of video tutorials on the SketchUp site.

[souls33k3r]

9 hours ago, DaveS said:

Have now installed Sketchup Make and trying ideas. Learning curve? More like a mountain! 

I wonder if @RayD and @souls33k3r have any ideas? .

Mate, wish I knew something to help you with it. I’ve been trolling through the forum and different posts and yet to build my own obsy some point in the future but I guess your post had ignited that flame within me to get up from my bottom and install and play around with the software. 

[DaveS]

FWIW I've pushed the button on "Sketchup for Dummies" and "3D Printing with Sketchup" from that long river thing. Should be with me on Monday.

[Astrokev]

47 minutes ago, DaveS said:

FWIW I've pushed the button on "Sketchup for Dummies" and "3D Printing with Sketchup" from that long river thing. Should be with me on Monday.

Dave - I'd also recommend checking out the SketchUp website. There's lots of videos covering all the basics, which I found invaluable.

Kev

[DaveS]

Thanks, I'll do that though I like to have a book open in front of me. Also useful for bashing my head against.

[DaveS]

More thoughts and cold feet.

Seriously doubting my DIY (Non)-skills so I'm thinking I could probably make an octagon about 1.5m high that a Pulsar short-wall dome could fit on. The base would still be 2.5mx4m with a 2.4m? octagonal obsy.

I'll keep my current Rigel pier and Telegizmos cover for the DDM60 which will go on the patio, possibly with a good foundation block to carry my current dual rig, and put a taller pier, possibly one of these:

http://astrograph.net/epages/www_astrograph_net.sf/en_GB/?ObjectPath=/Shops/www_astrograph_net/Products/AGEMCP20014M

in the dome to take a DDM85 Basic (On Rupert's recommendation) to carry a 12" RC, either the GSO version, or if I'm feeling flush a CFF one.

Having a larger base than the dome will mean there would be room for the door to open, and for a bit of eyeball observing at a higher level.

 

Thoughts?

 

Hell, I've only just started the legal stuff to buy the house, so it could still go belly-up. Won't relax till I've got the keys in my hot little hand .

[laser_jock99]

I found it fairly easy to 'knock up' my obsy- don't think I had aything other than basic skeches and a few ideas in my mind. The main focus was efficient use materials. For example- the wood beams came in 3m lengths, so the obsy & deck is 3m x 6m! Less cutting, lees waste. The steel wall panels and roof panels were 1m wide x 2.5m- a perfect fit for my 3m x 3m frame.....

You might want to consider siting the secondary pier outside? My so called 'widefield pier'. I use this for small scopes and camera lens work. Good for times when I don't want 'fire up' the main obsy