Planning My Observatory - Feedback Wanted!

Michael,

I built a roll-off-roof observatory a few years back (from scratch rather than adapting an existing shed). It's all detailed in this article:

www.nightskyobserver.com/Articles/Buildi...Own-Observatory.html

Cheers,

Gary.

Michael - personally I'd design now for whatever you will have in the next five or more years. You don't want to be building something now (which face it, will take a few months) which you need to redesign/rebuild come the SSIA.

I'd a say an accepatable cut-off is really based on what you really want to observe. I have no visibilty to the north at all but it doesn't give me major heart burn at the moment...

For polar alignment (drift) it is recommended you use a star to the East or West, no lower than about 15 degress and no higher than about 25 degrees. That might help put some limits on your design and/or location....

Gary - liked the description of your building antics!

Cheers

Dave McD

Gary,
Thanks for link. Interesting read. BTW, if you were to do it all over again, is there anything you would do different (apart from getting the plans from skyshed.com)?

Dave,
Yes, it would indeed make sens to build it once and build it right. Whatever I build I'd like to be able to put a bigger scope in it at some stage. One of the concerns I have is that truss dobs tend to pivot at the base. Put this into an observatory and you'll lose a load of stuff over the horizon. The only way around it is to build the observatory big and keep the walls low.
Alternatively, build the dob from a solid tube which can then be attached to a mount which connects to the centre of the tube. This would improve your clearances issues over the walls of the shed as the scope would now pivot at a higher point. However, you now have portability problems.
One of the things I've noticed is that alot of the observatories for larger scopes are designed so that the roof and part of the wall rolls off - i.e the whole thing splits in two. Strikes me as difficult to build though.

Alternatively, build the dob from a solid tube which can then be attached to a mount which connects to the centre of the tube.

...or build a big strong sturdy wooden box and mount the dob firmly on top. You could even fill the box with sand or other filler to make it rock solid.

Hi Michael - I think that's why Phil H designed his observatory as a roll-away shed - this gives him clear views for the big dob.

If you built a rool-away shed, you could do it so the base unit for the scope was just on the lawn to the west of the paving slabs and have the shed roll away to the East - up against the wall. Hey presto, no obstructions that you didn't already have.

I think the problem with having roll-off roofs and removable/movable walls is that you introduce more openings for the weather to get in.

I'm going to have a go at something like Phil's design - a roll-away affiar. I'm going to try and do it so I can roll the shed away pretty much in any direction. But a house-move could be on the horizon so I'm not committing just yet. Alternatively, I'll take Gary's web advice and get one of those Tak observatories and build it in La Palma.

Good luck with your choice!

Cheers

Dave McD

PS - isn't a Dob on a GEM just a Newtonian :

Gary,
Thanks for link. Interesting read. BTW, if you were to do it all over again, is there anything you would do different (apart from getting the plans from skyshed.com)?

I'd be more prepared, skill-wise, for building something like it. This was my first real building project and I made some fundamental (and dumb) mistakes in my rush to get it built. Having said that, and ironing out the initial problems, it's still standing despite Winter storms, is still waterproof and still does what it's meant to.

I'd use tongue-in-groove planking instead of plywood decoratively faced (too much work) for the walls and at 6 ft x 8 ft, it's only big enough for an 8" scope. If you're thinking of getting a larger scope in the future, factor that into the overall size of your observatory.

Cheers,

Gary.

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