I need some help planing an Obsy

[vlaiv]

I'm after some info on what people work with in their observatories.

Need info on used pier height and obsy space.

Will it be enough to have 2m x 2m deck for mostly imaging with "regular" sized scopes? Also, what sort of height should I go for with ROR deck?

Here is a bit more detail:

I have 3m x 5m allowance for auxiliary building - this is ground coverage. It needs to be max 3.6m tall - so it is just single level small shed type of building. I want to do some sort of gallery in it that will be deck for scope. I would also like to have space under gallery utilized as a storage or similar - and not wasted.

In fact, now that I'm thinking about it, will 1.8m x 1.8m be enough? What about minimum pier height if I want to observe (while seated)?

[Jkulin]

3 hours ago, vlaiv said:

I'm after some info on what people work with in their observatories.

Need info on used pier height and obsy space.

Will it be enough to have 2m x 2m deck for mostly imaging with "regular" sized scopes? Also, what sort of height should I go for with ROR deck?

Here is a bit more detail:

I have 3m x 5m allowance for auxiliary building - this is ground coverage. It needs to be max 3.6m tall - so it is just single level small shed type of building. I want to do some sort of gallery in it that will be deck for scope. I would also like to have space under gallery utilized as a storage or similar - and not wasted.

In fact, now that I'm thinking about it, will 1.8m x 1.8m be enough? What about minimum pier height if I want to observe (while seated)?

Hi Vlaiv,

I've attached the pier drawings of my pier, the top part was designed to accept a Altair Astro Pier adapter, but it could be any adapter as long as it is drilled correctly.

HTH

 

JK-Model.pdf JK Pier Drawing.pdf

[DaveS]

The obsy I'm building is 2 metre inside dimension, but it's imaging only and just large enough for me to squeeze around the OTA. For visual I'd be inclined to go larger, maybe 2.5 metre square.

OK, it's a big 'scope on a big mount, so perhaps for a smaller 'scope on a lighter mount 2 metre or so might do.

[vlaiv]

3 minutes ago, DaveS said:

The obsy I'm building is 2 metre inside dimension, but it's imaging only and just large enough for me to squeeze around the OTA. For visual I'd be inclined to go larger, maybe 2.5 metre square.

OK, it's a big 'scope on a big mount, so perhaps for a smaller 'scope on a lighter mount 2 metre or so might do.

When you say 2 metre inside dimensions and later say 2.5 metre squared what do you mean exactly?

I have object that is 4.7m x 2.7 m inside dimensions (5x3 ground allowance - so that minus minimal 15cm walls on each side) and I plan to make a "gallery" style observing deck on less than half this size - this is my current idea.

Now, I have an option to go for 2m x 2m + 0.7m for stairs to get to deck or perhaps to go with 1.8 x 1.8 and to have both more room for stairs - 0.9m in this case and also more room in main "volume" of the object - which should double as garden shed and observatory.

In first case, I'll have 2.7 x 2.7 + some small room under the gallery - it will be situated at 1.4m height, so there is enough height to put a desk under that will serve as imaging station and also there will be a bit of storage room as well.

In second case - I'll have proper width stairs (well, better than 0.7 in any case) and also bigger main "room" - at 2.9 x 2.7 but there will be a bit less space on the deck as it will only be 1.8 x 1.8 m

I'm also wondering if I could get a bit more height below the gallery - if I could get it then I think it would be even possible to sit below it as well as having table and monitor under there.

This is floor plan in my permit:

Side plan:

I have quite a bit of "room" to do things differently - like I don't have to have roof "slab" - I can go with just regular roof, and walls don't need to be 25cm thick - I can do 15cm ones (and I plan to do it to increase inside space.

Here is what I envisioned to do:

Now, the two obvious problems are - size of gallery / deck above and height of deck.

Half of the roof will slide over other half, so I'll get open deck like that. While I won't be building the whole thing yet, foundations will be done in about two weeks time (if everything goes as planned - not something that happened often this year) and I need to know where to put pillar anchor (that will be about 1 cubic meter of concrete and reinforcement and 200mm concrete reinforced pillar will probably be ok on that height).

 

[DaveS]

OK, I should have been more explicit.

My obsy is nominally 2.2 x 2.2 metres outside, so allowing for the wall studs at 95 mm thickness, that means about 2 x 2 metres inside.

Which is just enough room for the 'scope, and for me to squeeze round it during setup.

If I was visual rather than imaging I would want a bit more, which is why I said 2.5 metre square.

I think you *could* get way with a smaller footprint if you had a more compact 'scope than my ODK12.

looking at your plans, I think I would endeavour to make the platform / gallery affair a touch bigger else you might find yourself squashed.

Edited August 28, 2020 by DaveS

[fifeskies]

I would make the "deck" full depth and use a side folding trapdoor cover over the stair section.

So you lift the trapdoor style cover to the side , (let it flap against the rear wall) , step up onto the deck , then drop it back down.

This then allows you to place your pier central between front and back walls , and to have a generous space around the pier to work from.

 

I assume you will put some kind of bannister to stop you stepping off the deck as well.

In the dark , distracted by tinkering , its easy to forget where you are exactly.

 

I would consider making it a bit wider too , there is space before the door to expand it a bit.

Remember that due to the equatorial offset , the turning circle of the telescope is wider than you might expect .

 

My ROR space is a clear 2.2 x 2.2 metres internal, and its still tight when I have my big CT10L on the pier, but I can still just get past it at all 4 directions when the OTA is horizontal.

(I park horizontal to fit under the roof).

 

 

Edited August 28, 2020 by fifeskies

[vlaiv]

2 minutes ago, fifeskies said:

I assume you will put some kind of bannister to stop you stepping off the deck as well.

Deck will be surrounded by walls on three sides (at least meter and a bit high) and there will be sort of window section towards the main volume. This will effectively make main volume be like a large "warm room".

Something like this:

This is so I can monitor scope from below.

6 minutes ago, fifeskies said:

I would make the "deck" full depth and use a side folding trapdoor cover over the stair section.

So you lift the trapdoor style cover to the side , (let it flap against the rear wall , step up onto the deck , then drop it back down.

This is actually a very good idea - I was just thinking about it . Maybe it could even be "sliding" type door - there is enough room after the stairs to incorporate it into floor itself.

[fifeskies]

I said

"Remember that due to the equatorial offset , the turning circle of the telescope is wider than you might expect ."

Just noticed you are at a low latitude (20) , this wont be such a large issue for you , I am at 57 North and it does make a big difference.

 

 

[vlaiv]

3 minutes ago, fifeskies said:

I said

"Remember that due to the equatorial offset , the turning circle of the telescope is wider than you might expect ."

Just noticed you are at a low latitude (20) , this wont be such a large issue for you , I am at 57 North and it does make a big difference.

 

 

I'm actually at 45 degrees North - but thanks for pointing that out - will take it into consideration.

[fifeskies]

Oops , its 20 East, didnt read it carefully.

 but still , even at 45 North you are less affected by the "wobble" than us in the far north.

 

Easiest way to measure the "offset" is just to set your mount up and let it do a full RA circle and measure it from a marker or a wall nearby.

You dont say which direction your shed is sitting.

You might be lucky and find the offset takes your scope further away from the side wall.

[Rusted]

Don't ever have a "hole in the floor" in an observatory. I did and built a solid trapdoor to stand on.
It is a miracle I haven't fallen through the big hole in the floor down to the ground floor!
I even fitted counterbalance weights on ropes to make lifting the trapdoor completely effortless.
It is still far too tempting to leave it open to save time. Or in case I need to go and collect something indoors.

 

[fifeskies]

A small simple safety feature if you are worried you might forget to close the trapdoor.

 

Mount a battery powered automatic light on the underside.  The type activated by movement.

With the door open the light shines everywhere to remind you the door is open as you will be triggering it as you move around (make sure the trapdoor opens so that the underside faces the mount)

You will never forget to close the trapdoor before starting your observing, and a bonus is that after you close the trapdoor the light goes out after a short while so doesn't even leak through the gaps.

 

Handy to see where the steps are too when ascending/descending.

 

 

 

Edited August 31, 2020 by fifeskies

[Rusted]

I chose to have a permanent red light inside my huge, hollow pier.
It throws a light straight onto the open trapdoor at night.
As well as lighting the ladder of course.

The daytime is when I spend the vast majority of my time imaging.
The only safeguard, then, is fear of falling into the void!
But at least it is well lit when the observing slit is open.

I have a feeble excuse for the internal ladder rather than outside.
A greater fear of ice and snow accumulating on my steep, aluminum stepladder.

Had I chosen the external stairs I could have had a much more gentle slope.
There is also the security aspect of poor external access with an internal stepladder.