Portable Observatory

ReaPerMan (Paul) · #1 16-04-2010, 07:10 PM

I have started building the portable observatory mentioned in my post the other day http://www.iceinspace.com.au/forum/s...ad.php?t=59707. I shopped around and came to a final price for the poly pipe, fittings wheels etc of $270.00. I now have to organise the Polytarp covering and have seen some that i could modify to cover this in one piece for $65.00 on e-bay. Today was to start cutting and fitting the poly pipe together to see how it went. Because there are no plans available for the old "cover Your Astro" design I had to guess at the sizes and work from there. I have gone for a horizontal stringer size of 1.2M with a riser size of 1.5M once the 150mm wheels are added this will come to the perfect hight for my C9.25 on my HEQ6pro mount. What really surprised me was just how much width was added by the 45 degree elbows and T pieces. The internal dimensions at this scale come to 3 meters in diameter. Plenty of room for all the gear you could ever want inside. For those pushed for space it would be simple enough to reduce the horizontal stringers to 1 meter which would reduce it to about 2.4 meters internally.

Construction is a breeze and is safe for moderately DIY challenged to attempt. If you have ever used Lego or Meccano your already an expert!

The next phase will be to channel my internal dressmaker to make the best possible cover, that doesn't leak!!

I have attached pics of the work so far, as you can see I have a very narrow yard with an enormous limestone wall on north side (it even has a house sitting on it!). When standing inside i have very good views to the East, South and West with 40 degrees of North missing. This is not strictly bad as the Kwinana industrial strip is in this location with all it's associated light pollution.

I'll update as I complete more of the project, For now I have nightshifts for 2 nights before i'll be able to try it out!

Paul

michaellxv (Michael) · #2 16-04-2010, 07:34 PM

Looking good Paul.

What sort of covering are you looking at? I am moving ahead with my own project but have not finalised what to use for the walls.

ReaPerMan (Paul) · #3 16-04-2010, 08:20 PM

Quote:

Originally Posted by michaellxv

Looking good Paul.

What sort of covering are you looking at? I am moving ahead with my own project but have not finalised what to use for the walls.

I have been looking at a range of Polytarps that are available on E-Bay (http://www.wildearth.com.au/kookabur...arp-p-321.html), They are the usual Green/Silver combo and I intend to fit it to shape with a combination of Glue, Stitching and Velcro. Internal attachment to the frame is hopefully from stitched in Cotton 'ties' (just like a lot of tents. This should stop flapping and keep the integrity of the shape.

Of course waterproofing will be an important issue so plenty of overlap and attention to run off is essential.

All the best

Paul

seeker372011 (Narayan) · #4 17-04-2010, 05:31 PM

Hi Paul

where did you buy all the plastic fittings for the obs?

Narayan

ReaPerMan (Paul) · #5 17-04-2010, 08:04 PM

Quote:

Originally Posted by seeker372011

Hi Paul

where did you buy all the plastic fittings for the obs?

Narayan

I have an outlet called Poly Pipe Traders right near my house and they gave me a discount. I also went and priced up parts at a couple of stores including bunnings. It pays to shop around. Remember I have built the large economy size and if you are going to build the 8 footer then you only need to use 25mm pipe and fittings which would be much cheaper. The breakdown is as follows.

32 X 45 degree elbows
12 X Cross pieces (hard to get at some places as they are not strictly standard)
8 X T pieces
8 X 6" Wheels and Bolts and washers to fit. For 40mm pipe buy 100mm bolts.

For a horizontal stringer of 1.2 Meters I required 8 X 6M lengths of pipe.

I have attached a picture of what you have to make with these parts and the quantities.

I hope this helps.

all the best

Paul

thunderchildobs · #6 17-04-2010, 08:47 PM

How are you going to secure it?

A friend had a simple box structure made from PVC pipe and covered with tarps. The tarps act like a large sail. I remembering seeing it rolling end over end through the main observing at the QLD astrofest. Lucky it was early in the week and no damage was done. If it was the last friday / saturday it would have wiped out half a dozen scopes.

ReaPerMan (Paul) · #7 18-04-2010, 01:46 AM

Quote:

Originally Posted by thunderchildobs

How are you going to secure it?

A friend had a simple box structure made from PVC pipe and covered with tarps. The tarps act like a large sail. I remembering seeing it rolling end over end through the main observing at the QLD astrofest. Lucky it was early in the week and no damage was done. If it was the last friday / saturday it would have wiped out half a dozen scopes.

I would agree that this can be a concern and in high winds it could pose a real hazard. I built a simular structure a few years ago as a shade house for my wife's orchids and I found that U shaped pegs pushed over the gound tubing worked very well. If the weather was turning inclement or was gusting strongly this would be my most likely approach.
I do like the visual imagery of you comment above

all the best Paul

seeker372011 (Narayan) · #8 18-04-2010, 07:48 AM

Thanks Paul
Narayan

Montana_Nights (Justin) · #9 07-05-2010, 06:20 PM

Hi Paul- I decided to register on this forum b/c of your post (though I'm in the US and not AU!). This is EXACTLY the kind of thing I've been looking for for awhile now. A few questions if I may, how long are the vertical roof struts and the horizontal stringers that form the roof? The most challenging thing I think will be making the coverings fit!