Re: mast / pole for wind gauge / direction
Posted: Sun 26 Dec 2010 6:51 pm
I'm looking into this whole mast business again. I'm fed up with my Heath Robinson rig of 6ft of 2" galvanised water pipe, then a 2m piece of 28mm water pipe and topping off .with a 3m piece of 22mm copper water pipe stuck into that. The copper pipe bends rather easily as copper is soft. I can't stay it properly as it's on the boundary of our property. I have one guy wire supporting it from the prevailing SW wind direction. Not only is it rather floppy but it's also heavy and a struggle to get up and down. (And I will keep modifying my wind sensors!!).
I have found what seems to be a reasonably priced web site for aluminium tube in the U.K. and they have a vast range of sizes in stock. The URL is http://www.aluminiumwarehouse.co.uk. Main snag is cost of shipping of £15 (15 UK pounds) plus VAT. But if I can get all I want in one go that isn't too bad.
They do two grades of aluminium alloy, one is designed for strength and for mechanical structures (6082T6), the other (presumably a softer alloy) more for decorative use and where the tube is supported (6063T6). I shall go for the former.
Next consideration is the size and wall thickness of the tube. I'm thinking of two parts, thicker at the bottom and thinner at the top.
Bottom section :- Aluminium Round Tube (6082T6) 1.75 in x 10 swg (44.45 mm x 3.2512 mm)
Top section :- Aluminium Round Tube (6082T6) 1.25 in x 16 swg (31.75 mm x 1.6256 mm)
Now I really don't know how stiff and strong this would be. Both sizes are available in 2.5m and 5m lengths. Using 5m for both sections would give nearly 10m (allowing for a sufficient overlap). I propose fitting the top section inside the bottom with suitable spacers. Alternatively, the mast could be in three sections, which I imagine would work out cheaper and lighter. No, I'm not suggesting 15m high Using shorter lengths. The permutations are almost endless.
Are there any structural engineers around or metallurgists with more information?
I have found what seems to be a reasonably priced web site for aluminium tube in the U.K. and they have a vast range of sizes in stock. The URL is http://www.aluminiumwarehouse.co.uk. Main snag is cost of shipping of £15 (15 UK pounds) plus VAT. But if I can get all I want in one go that isn't too bad.
They do two grades of aluminium alloy, one is designed for strength and for mechanical structures (6082T6), the other (presumably a softer alloy) more for decorative use and where the tube is supported (6063T6). I shall go for the former.
Next consideration is the size and wall thickness of the tube. I'm thinking of two parts, thicker at the bottom and thinner at the top.
Bottom section :- Aluminium Round Tube (6082T6) 1.75 in x 10 swg (44.45 mm x 3.2512 mm)
Top section :- Aluminium Round Tube (6082T6) 1.25 in x 16 swg (31.75 mm x 1.6256 mm)
Now I really don't know how stiff and strong this would be. Both sizes are available in 2.5m and 5m lengths. Using 5m for both sections would give nearly 10m (allowing for a sufficient overlap). I propose fitting the top section inside the bottom with suitable spacers. Alternatively, the mast could be in three sections, which I imagine would work out cheaper and lighter. No, I'm not suggesting 15m high Using shorter lengths. The permutations are almost endless.
Are there any structural engineers around or metallurgists with more information?