[TowerTalk] Homebre Aluminum Tower...

[Jim Lux]

On 8/10/15 10:41 AM, Douglas Ruz (CO8DM) wrote:
> Hello everybody !!!!,
>
> I am still trying to build a tower...
>
> I found many Aluminum tubes here...they are 6 ft long and 1 1/2 inch
> diameter with 0,08 inch wall...those tubes have been working in a heat
> exchange equipment but are like new...i dont know the type of Aluminum...
>
> Is is possible build a Triangular tower adding "Z" braces joined with
> Rivets???...a guyed tower like Rohn 25G, etc...
>
> I have been trying to build a tower (antenna) for low bands but maybe i
> can install a light weight tribander (spiderbeam) on top...not sure if
> that tower is strong enought for climbing.
>
> I will apprecciate your comments.
>


It's certainly possible. Since you don't know the material, and 
strength, and so forth...

What I'd do before investing a huge amount of time is build a short 
section (6 ft long, because that's how long your tubes are) and do a bit 
of testing.  You can bolt it so it sticks out sideways from some sturdy 
support and stack sandbags on it to load test it.

How tall do you want to go?

If you're guying it, you don't need to climb it, and you're just holding 
up wires, maybe you don't even need braces.. You basically put up a 1.5" 
diameter aluminum tube that's 50-60 feet high or whatever.

If you need a bit more stiffness, you could probably bundle 3 tubes 
tightly together.  THink about using 3 tubes, and spacing them with 
short pieces of tube (6 tubes around a center core tube).  The center 
core tube is 3-6" long, as are 3 spacers.

You could use standard "banding" gear like you use for crates to hold it 
all together, or rope, or big hose clamps.

Put 7 identical coins on the table and make a hexagon, and you'll see 
what I mean.  spreading the tubes out a bit makes the overall diameter 
of the assembly bigger, which makes it stronger and stiffer.

Or if you have something else you can use as a spacer, you could use 
that. Heck, you could use triangular pieces of plywood with semicircular 
cutouts at the corners into which the tubes nest.

People put spiderbeams up on a pretty lightweight 40foot carbon fiber 
tube mast.

This is a lot like using thin wall irrigation pipe.