Towertalk
[Top] [All Lists]

Re: [TowerTalk] Joining sections of aluminum mast

To: "TowerTalk@contesting.com" <TowerTalk@contesting.com>
Subject: Re: [TowerTalk] Joining sections of aluminum mast
From: Grant Saviers <grants2@pacbell.net>
Date: Sat, 20 Aug 2022 16:29:55 -0700
List-post: <mailto:towertalk@contesting.com>
A lot depends on what rotator and how tall is the tower?

I would recommend machined internal sleeves either of solid 6061 or tubing with enough wall thickness to machine the od to fit the mating tube id's. I don't think slitting and expanding 6061 is practical with adequate wall thickness - min 1/8".

With a top thrust bearing, there will only be the tube or pipe weight on the bottom rotator. That tube will only have to handle the rotation torque loading, no side bending from wind. Probably 1-1/4 NPT pipe would be strong enough, backyard engineering. Threaded couplers with a 3/8 gr5 thru bolts in drilled holes to prevent unscrewing.

However, I'm not in favor of adding a long torque tube spring to an already complex tower-rotator-mast-boom-elements dynamic system.

Grant KZ1W

On 8/20/2022 16:08, Dave KØEKL wrote:
To ease maintenance I want to relocate my rotator to the bottom of my tower.

The existing mast is 2" diameter ¼" wall 6061-T6 aluminum tubing. The rotor is 
8 feet below the top of the tower / thrust bearing.

What is the best way to join additional lengths of tubing together to reach the bottom? I'm thing 
about buying tubing that is 2" ID, cutting it into 18" or 24" sections, slitting it 
and slipping it over the 2" OD sections to be joined and clamping with SS U-bolt clamps like 
those sold by DX engineering. Will this provide enough coupling friction between sections to 
prevent slippage?

Also, can I get away with using 1/8" in wall 2" OD tubing from the existing mast to the 
base of the tower or should I use ¼" wall all the way to the bottom.

Thanks.

-Dave K0EKL
_______________________________________________



_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
_______________________________________________



_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
<Prev in Thread] Current Thread [Next in Thread>