Tall column piers and alternatives

[nightvision]

I am about ready to construct my imaging obs which will need to be about 3.7m tall. The mount will be at about 2.5m above the ground (to help see over tall trees and buildings).

Pier challenge:

I don't think it will be practical to build a rigid conventional pier pillar. To be rigid it would likely need to be at least 300mm in diameter and braced (probably cost more than my mount!).

I have some 50mm steel piping and various other scaffold like pipes. I am thinking of constructing three 200mm diameter pillars (fixed in the usual concrete blocks) and cross bracing them (triangular in plan view) to achieve rigidity (will need to add dampening too). This will present three contact points above the raised floor to which I could attach the 3 NEQ6 tripod legs. Another option (to avoid tripping over the tripod) could be to connect the three contact points with a rigid stable floor and install a single pillar to support the mount.

Interested in any feedback or ideas,

Tony.

[Steve Ward]

Something like this ?

http://en.milosgroup.com/assets/1/15/Small%20mediumtrusses1.PDF

[JamesF]

I couldn't tempt you with one of these:

http://www.ebay.co.uk/itm/Galvanized-Steel-Spiral-Ducting-3-0m-Hydroponics-Ventilation-Extractor-fan-/110819610063

filled with concrete?

3m @ 315mm diameter for £45.75 delivered. Larger diameters are a fair bit more expensive.

You could even potentially do, say, 1.5m in 315mm, put a 315mm to 200mm reducer in and do the top section in 200mm.

James

[nightvision]

Something like this ?

http://en.milosgroup.com/assets/1/15/Small%20mediumtrusses1.PDF

That's the sort of thing I was thinking of constructing, multiple triangles but much more damped. Thinking of 110mm or 160mm plastic pipe filled with concrete and sand, drainage pipe has lots of connectors (including 45 & 90 degrees), combining that with steel may do to trick. I did consider wood but it will move about for sure.

Another cheap alternative could be to use blocks cemented to form a 1 metre high pyramid with a normal pier on top.

Just thinking/designing out loud at the moment...

[nightvision]

I couldn't tempt you with one of these:

http://www.ebay.co.uk/itm/Galvanized-Steel-Spiral-Ducting-3-0m-Hydroponics-Ventilation-Extractor-fan-/110819610063

filled with concrete?

3m @ 315mm diameter for £45.75 delivered. Larger diameters are a fair bit more expensive.

You could even potentially do, say, 1.5m in 315mm, put a 315mm to 200mm reducer in and do the top section in 200mm.

James

Nice find James, I didn't know about that. If it flexed I could surround the lower part with some heavy blocks. I think that may be the way forward, this forum is superb!

Tony.

[JamesF]

Have a hunt around to see if you can find other prices. That was just the first one I found, though it seems reasonable to me.

James