obsy size

[oldnut]

evening all, been trying to work out the minimum/ comfortable fit size for my obsy. I will be using a sw200 in it, so standing it in the living room and using a ring of chairs/stools/boxes etc I think a 2.2 mtr  circle will be a goodish fit...I think. (by the way I am either building a dome or D shaped obsy)  what do my more learned colleagues think?

[laser_jock99]

The other way of approaching this is to look at the sizes and availability of construction materials. My observatory is 3m x 3m- for no other reason than 3m is a standard size for the 4"x4" timbers I used to build the framework. With a 3m frame standard 1m wide steel covering panels are a perfect fit. Similarly the panels come 2.5m tall- which I used as the wall height! Less cutting, less waste and a reasonable sized working space.

Frame based on 3m 4x4 timbers

[oldnut]

that is a solid looking job! mine can go to 2.5m but that would be about it without it being visible (trying to keep it hidden behind the garage)  I also like the idea of a round one as I have built many sheds but never a round one

[Robd]

Go for as big as you can.  I made the mistake of going to 2m and it is a bit too tight, not too much of a problem in my end for imaging but in the other dome ( we have a two domed obsy - his & hers ) my wife struggles more since she does visual astro ans is frequently bumping her head.

Rob

[Peter Drew]

Build the biggest you can get away with rather than the smallest. As mentioned, designing around standard sections is very cost effective and time saving. 

[Tinker1947]

As big as you can go, the scope is rear heavy so the front will stick out a bit more, a warm room or section with shelter makes a big difference to your comfort and keeps the dew off maps ect....if your D shape can accommodate a section along the straight edge may be 3' deep so you could have a section either side of the middle sectioned off with a stud wall....

[Mav359]

Don't make my mistake.......

I built my OB's to just fit only to find later that this hobby never stops and my scope got bigger and longer and suddenly i was bangin the mount off the side walls. Mine was desinged with the ability to extend it in mind but in practice (whilst it worked) it was difficult.

Big as you can get it

[oldnut]

thanks for the input, it would appear size is everything. the reason for the limited size is that the garage will hide it from the road BUT it will be right in front of the kitchen window, albeit about 8 feet away. maybe cover it in growy flowery things....

[michaelmorris]

.... maybe cover it in growy flowery things....

Has the advantages of helping keep it cool in summer and helps camouflages it from the prying eyes of crims.

[r3i]

Build the biggest you can get away with rather than the smallest. As mentioned, designing around standard sections is very cost effective and time saving. 

That's what I did: the timber lengths that I used were sold in 2.4m lengths so I've ended up with a 4.8m x 2.4m structure split 50-50 between the scope and warm rooms.

[Owmuchonomy]

As above, base it on the materials available 2.4m or in old money roughly 8' x 8'.  Ive just finished mine and for the eclipse we got me, 4 mates with bacon sandwiches and my 4" frac in comfortably.

[spaceboy]

Go for as big as you can.  I made the mistake of going to 2m and it is a bit too tight, not too much of a problem in my end for imaging but in the other dome ( we have a two domed obsy - his & hers ) my wife struggles more since she does visual astro ans is frequently bumping her head.

Rob

I agree with Rob. My 2mtr dome obsy originally housed a TAL 200K on an EQ5 which gave me plenty of room to move around but as the years have passed my requirements of the hobby meant that the Klevtsov went and a meter long 200P took its place which has now been replaced by a bigger 250PX on EQ6 which now leaves me with the constant risk of bumping into something in the dark. While I can manage in the obs had it been another meter in diameter life would be so much easier.

Obviously if your intentions are imaging rather than visual you can get away with a smaller obsy for the scope as a warm room can always be added at a later date.

[kirkster501]

Why is 2.4m a standard length I wonder?  The wood yard near me does most things 2.4m or 4.8m.  Seems an odd number, why not whole numbers like 2m or 4m?!

Back on topic I am going to do 2.4m square as well.  I am not bothering with warm room I don't think, though I change my mind four times per day so ask me again in ten minutes......

[Tinker1947]

If there is room for a warm room but its not in the plans, make the wall where it will go easy to change, my rear wall has a 2'6" gap all that's required is a jig saw run down the inner and outer wall both sides and that the entrance to a warm room, i do think having lived without one if it can do it as part of the Obby build and save time ect you won't be sorry it there....

[Bizibilder]

2.4m is a nominal eight feet and 1.2m is nominally four feet - so the "old" 8' x 4' sheets of builders stuff became 2440 x 1220 mm.

As to observatories - I had a slightly less than 6' x 6' square one which was fine until you wanted to get past the scope!  A wee bit too tight.  I now have 7' x 7' (plus a "warm space" of 7' x 2'6") and there is enough room all round for me to "slide" past the scope rather than having to crawl around on the floor - most undignified!

[Owmuchonomy]

Why is 2.4m a standard length I wonder?  The wood yard near me does most things 2.4m or 4.8m.  Seems an odd number, why not whole numbers like 2m or 4m?!

Back on topic I am going to do 2.4m square as well.  I am not bothering with warm room I don't think, though I change my mind four times per day so ask me again in ten minutes......

Roger beat me to it. Most tradesmen still work nominally in feet, well they do up here anyway. I paid more attention to my warm room than my obsy. Don't underestimate it's usefulness.

[wxsatuser]

Why is 2.4m a standard length I wonder?  The wood yard near me does most things 2.4m or 4.8m.  Seems an odd number, why not whole numbers like 2m or 4m?!

Back on topic I am going to do 2.4m square as well.  I am not bothering with warm room I don't think, though I change my mind four times per day so ask me again in ten minutes......

Do a warm room, I did'nt because a lack of space and regret it, looking to add an extension now.

[Charic]

Wow! that looks like a solid shed. It would be nice to see a series of images as you progress, and at what cost do you envisage this  project. I  too need a new shed, to replace others?   I'm envious already

[kirkster501]

Laser-jock, what are the fasteners you used to join the main beams on your build please? 

[laser_jock99]

Laser-jock, what are the fasteners you used to join the main beams on your build please? 

Wow! that looks like a solid shed. It would be nice to see a series of images as you progress, and at what cost do you envisage this  project. I  too need a new shed, to replace others?   I'm envious already

A gallery of my entire build may be found here:

http://s48.photobucket.com/user/laser_jock99/library/ASTRONOMICAL/Cambrian%20Mountains%20Observatory?sort=3&page=1

Cost wise I think my build came in about £3k - but there was a huge amount of ground work that won't apply to most sites.

Laser-jock, what are the fasteners you used to join the main beams on your build please? 

The biggest, strongest brackets I could find bolted on with 3" coach bolts. The site is 1300 feet up and quite exposed so I went heavy duty on everything.

[jnb]

Sheet materials come in standard sizes of 2.4m x 1.2m, insulating materials typically come in 0.4m widths, so 2.4m would be a good size if you are genuinely pushed for space. Having said that bear in mind that an external size of 2.4m could easily be 2.1m or less internally.

[jnb]

Why is 2.4m a standard length I wonder?  The wood yard near me does most things 2.4m or 4.8m.  Seems an odd number, why not whole numbers like 2m or 4m?!

Back on topic I am going to do 2.4m square as well.  I am not bothering with warm room I don't think, though I change my mind four times per day so ask me again in ten minutes......

Multiple of 6", 1ft, 16", 24" which are all standard sizes of building materials. That said none of those sizes are exact they are just nominal. So for example 2x4 PAR is more likely to be 95mm x 45mm but it is still "2x4"

[mikeDnight]

evening all, been trying to work out the minimum/ comfortable fit size for my obsy. I will be using a sw200 in it, so standing it in the living room and using a ring of chairs/stools/boxes etc I think a 2.2 mtr  circle will be a goodish fit...I think. (by the way I am either building a dome or D shaped obsy)  what do my more learned colleagues think?

Corners are wonderful things. In a round observatory things can get under your feet.

I built mine 8' by 7' and it allows room for chairs, a small table and fellow observers to remain safely out of the way.

[oldnut]

well still clearing the ground but have made a start on the prelim drawings. I seem to have headed of in an untried direction, be interesting if it works!