http://www.concretetaxi.com/ Check out the videos on the site. Basically the truck is full of blend and water, they push that into the mixer bin on the back of the truck and add bagged cement to obtain the requested strenght. The mixer bin has a huge screw in it to mix and dispence. Here's a price list but I dunno if they are in Adelaide, it is a Perth based franshise.. That may be Brisbane prices?
It's not cheap but it's definately easy and quick and from what I calculated, it cost me a lttle more than premix bags, minus draging the trailer out to get the bags, not to mention mixing them in a barrow.. I didn't bother checking costs for mixing it myself with a mixer, it was just too small a quantity to consider it and I'd end up with lots of left overs to deal with. This way you don't even have rubbish to go in the bin
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They made 2 mixer loads for me (6 wheel barrows full) I had one barrow load left over and used it under the wheely bin spot instead of tossing it. There is always somewhere you need concrete
Another day with very little work on so I got the dome glued to the top ring, no wheels yet. It's got 2.45meters of head room and 1.85meters internal diameter between the inside ring edges and is looking more like the goods now. Still need to add internal reinforcing to the dome and some extra bracing to the frame but that should only take a day with a saw.
Also tested my wheels idea on an offcut. I'm going to route them into the turntable to reduce the gap between the top and bottom ring. Cut up some 6mm brass rod for axles. Looks like a worker
No Geoff it will never clear up now, although the days are clear, got a touch of sunburn today.
Doug, at least I'll have some where to set the stuff up. It's still all packed up since the last trip away in early September
Cheers guys, it all seems to be going almost as planned although it's a little taller than I imagined it would be. Seeing its right beside the pool fence, I had to make sure there aren't any hand holds or steps so I made the the wall tall enough to be part of the fence. They are doing random pool compliance checks up here and coming down hard on pools that don't comply.
However, I'm not looking forward to doing the shutter, at all. How wide should the opening be? The original plans show one triangle which is about 600mm on his plans but that's only 400mm wide on this dome. If you look from inside it's obvious the top pentagon should go and then follow the joins down but that makes for a curved opening, 800mm in the middle and 400mm top and bottom. I'm not keen on making a curved shutter, square is good I don't think 400mm is wide enough, 600mm sounds right. What do they use on a bought one?
Nice project. Just out of curiosity of its strength against UV and wind; would covering this in paper mache or something similar be beneficial in improving strength and lifetime?
Nice project. Just out of curiosity of its strength against UV and wind; would covering this in paper mache or something similar be beneficial in improving strength and lifetime?
I'm going to render the dome in concrete. It will add 45Kgs to the weight and cost about $30. It's definately not water proof as it is nor is the glue I used. It currently looks like this, and it's raining again But at least I can work inside
robin before you clad the walls think about putting some power points in the stud work you can never have enough power...
small fan, red light, mozzie zapper these little luxuries in a dome
Not a lot of activity this week, weather has been dreadful, constant passing showers, always overcast, yuk. However I got inside the thing and put in the dome reinforcement around the whole dome and got the bracing into the wall.
The wall wasn't stable enough as it was. Give it a bump and it would wiggle, I'm sure I could have pushed it over if I tried hard enough. I have braced it each side of the door way and braced a bay opposite the door way. Thanks to Dave (Brundah1) for the tips. It doesn't wiggle now, it's solid as. Similarly the dome is 300% more secure. You can punch it from the inside and it just feels solid.
Thanks to allan gould for letting me come over and check out his sirrus dome. I now have the shutter plans ready to roll and have started on the rings for the shutter.
Allan, I set up the scopes inside and used the caveman version of lasers around the scopes. Broomsticks and tape
Allan, it's looking like the shutter will have to be 650mm wide minus the shutter framing, 42mm, so about 610mm. It is a small dome, 2100 O/D. I can't make the opening any longer either or the door won't roll round the dome. I note the sirrus domes solve this issue with a flip out door.
Therefore I see a problem with the 10". If it's looking east and then eventually pointing straight up, the dome will have to be rotated before it gets to azimuth or it will not see some of the sky, the slot will not be long enough. I can still move the pier a bit, It's bolted down with concrete bolts, but I'll suck it and see first. If I manage to automate it, I might be able to fix that in software. However I think this is a penalty of having a small dome.
Hi Robin,
Congratulations on your achievements so far!
You're doing a mighty job, and can't wait to see the Observatory completely finished and ready to go.
Are you planning an Observatory warming party??.......just kidding!
Best of luck with your final finishing touches, and hopefully the rain stays away for you.
cheers,
Peter
p.s. i am getting good results with my qhy8pro.
Hi Pete, exactly when are you getting to use that camera
I don't think it's ever going to clear, I've even stopped checking the weather sites
More progress photos. Got the dome off the wall to do the shutter, so the wheels are in, the shutter ring is made and I've sealed the foam with paint I found in the shed.
After talking to a few people, I've decided to seal the doam with acrylic paint under the render as the render will most likely crack at some stage. I've given it a couple of coats of the paint I had here and good old bunnings had a litre of stone finish acrylic on the wrong tint pallet for $6. This stone finish paint has a texture like sandpaper which should help the render to stick as well as being the final sealing coat on the doam.
I hope to get the shutter in before the boy child has all his mates over here on Sunday for a BBQ.
