After a year or so procrastinating on design, I've got a foam dome obs underway.
Many thanks to Steve (Kinetic) for inspiration and email support as well as Baz at A.S.I.G.N. for a brilliant web site, not to forget Joe Garlitz who got the ball rolling.
My pier is in, the foam is now a dome and the rings are under way.
I've plonked photos and a story online but here's a few pics anyway.
Robin, it looks great! The Pier looks good too, and has held up very well, I am the original maker of that pier, so I hope it serves you well into the future. The construction looks very good, and the foam will serve as a great insulator of heat too, great design. Good luck with it all in the future. Look forward to seeing more as time goes on.
That is looking great, i am also interested in this design using foam as well but have to move house first as there is not enough room to assemble it and the remove it if i do move.
I am getting a little fed up moving the scope in and out of the house or garage all the time.
Cheers Andrew, Alex said he transported it from S.A. on the cheap, the thing weighs a ton. I got a sheet and a half of foam left and thought I'd line the 1.2 meter wall with it rather than toss it. There was far less waste than I thought there'd be.
It's a little daunting when you've cut all the triangles and see just how many there are Malcolm. I've scalled this one back 30% to fit in the back yard, so the edges on my triangles are about 400mm instead of around 600mm as per the plans. That makes it easier for one person to manage while building but it still took 2 of us to lift it and turn it over
looks good robin - I didn't realise when you posted photos in the Ten Chain Hill thread that you had cut all those pieces yourself - that must have taken some doing?!
Are you happy with the strength of the dome now its all glued together?
Yes it is, especially when you can see the end of the tunnel. Now if it would only STOP RAINING !!!!! I could get the circular concrete floor underway.
Here's a couple more photos Pete.
Adam, I knocked up a quick cutting bench (see pic) with a cutter on the end and then cut the bench up for the rings once the foam was done Once you get a rhythum going it happens pretty quickly. I cut 2 triangles out of 4mm MDF with a box cutter and a metal straight edge and used them to draw cut lines on the foam. When it was complete and upside down the edges where a bit wobbly but right way up it's surprisingly ridgid, like an egg I suppose. It still needs the bottom ring and associated internal reinforcing to go onto it and a waterproof coating, render or similar will do it and I shouldn't forget the shutter I guess
Quote:
Originally Posted by HCR32
Want to build me one? $$$$
No, once is enough for me thanks, I'm totally foamed out
aahhh !!! i see robin its the dome and the walls are coming... youve taken on a task here and your doing a bloody good job...what are the walls going to be made of..????
Just framing pine with a ring top and bottom to keep it round and probably alsynite around the outside on a concrete floor. If it stays fine I should get the floor done this week-end, well most of it. I had to do the dome first to get an accurate diameter for the rings. It only needs to be 1.2meters tall and I might add a pod sticking into the garden bed. I swapped a TV for an eeep box yesterday so that makes the control PC nice and small The pc is that box screwed to the back of the monitor.
The dome looks very neat - well done on tackling this design. Please keep the pictures coming. Do you happen to know its weight? I enjoyed reading your blog - brought back a few memories. Mine was built from 9 mm plywood (also 105 triangles) and is much heavier of course.
I'll be interested to see what you do to waterproof it; mine is just numerous coats of a thick waterproof paint. The geodesic shape is inherently strong, and once the dome's base ring was fixed in place, the whole thing stiffened up considerably. Of course, cutting the slot weakens it, but adding the frame in that aperture brings it back to a strong shape.
I might add a few dome construction pics to my thread later - just realised that I don't have any there.
If I had to guess Chris, I'd say 15-20Kgs and probably 1/3 of that is glue It's hard to estimate as it takes 2 to lift it due to the size. A client of mine is a builder and he suggested coating it in sikaflex pro which is sort of like a hi-end long life silastic, but I think cost will kill that idea, render will be the cheapest way to go.
Boxing is in for the concrete and I banged in some expansion joints so it doesn't push on the pool or the pier footing or visa versa. I'm going to get concrete taxi to do the concrete, quick, easy, no left overs and no mess, and not much more dollar wise than bagged pre mix to be honest.
I also trimmed the bottom of the dome to make it flat. As all edges of every triangle are tapered, the bottom of the dome is also tapered so it's not flat, which makes for a poor glue bond to the turntable. I also found this one was up to 25mm away from true (see pic). However, the foam is pretty easy to work with, I knocked up that cutter in no time at all and ran it from my dew controller. I measured down from the ring, set the string to distance all the way round, drew a line with a marker and cut it. Hint, red hot is tooo hot for the cutter, that just makes holes
I also got the eee box cleaned out and setup for Astro Apps and remote control.
It has wireless built in but it's a gutless CPU. For control it should do ok.
I'll keep my eyes open for a cheapish Solid State Hard Drive.
Also Brundah1 has put me onto some quality wood glue. TITEBOND III water proof wood glue from http://www.hardware.net.au/
I also found 10litres of paint in the shed so just finished painting the bottom ring. Back to making more rings tomorrow
oh, and thanks to ChrisM for some great ideas via email ...
The floor is in. Concrete Taxi arrived today but the damn camera went flat so only got one crappy pic of the truck before it died completely. The pour ended up being about 4 square meters in area and cost $210. Best part is that it only took an hour and a half to pour and finish the slab. Magic
I want to get the turntable done first so I'm laminating, glueing and screwing the bottom turntable ring tonight seeing the wood has been cut. I already have the bottom ring/plate for the wall done and painted and I picked up a few concrete self tappers today to bolt it down. I'll need to pay more attention to detail on the top two, they need to be right. Won't get much else done this week-end, it's full bottle with social events and they are forecasting rain through Saturday/Sunday anyway.
One tip, new jigsaw blades make cutting plywood a whole lot easier
Last edited by Tandum; 05-11-2010 at 02:25 AM.
Reason: add pic
Bit of action here today. Both turntable rings have been made and matched, the upper ring overhangs the lower ring just enough for the weather proofing to take effect, I hope Sand and paint tomorrow on them.
Also bolted down the bottom plate for the wall, got the geometry done and worked out the entry etc etc. I see the end of the tunnel
Lookin good! I should do more on mine, but it's raining
I have been looking for a small quantity concrete place here in Adelaide too... I like the idea of them mixing it on site, was the batches the same consistency though? Do they mix the whole lot then pour or is it single bags at a time?
