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Crank up mast homebrew plans??



 
 
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  #1  
Old September 11th 03, 03:12 PM
Gary V. Deutschmann, Sr.
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Default Crank up mast homebrew plans??

Hi Andrew

They are not complicated enough to need plans for!

I have built several, after smashing my fingers a few times on those
darn push-ups.

One thing I do different now than I did at the beginning was that I
feed each section independently. It takes a lot more cable, but it
sure makes for a safer install on guyed towers. Albeit a bigger pain
playing with all those cables though.

Threading a single external cable unit is fairly easy and
straightforward and the addition of pulleys rather than cable guides
makes it easier to crank up. Internal cable works basically the same
way and the cable is still exposed at the pulleys, unless their are
rain caps over the pulleys.

If your wondering how some are cabled, different companies do it
different ways, but the most common is for the cable to be affixed to
the lower end of the top section, about 1 foot from the bottom of this
section. It feeds through a cable guide or pulley on the top of the
next section. From this point the feed varies for internal or
external showing cable. The norm is internal. So there will be a
cable guide just below the pulley, where the cable feeds back into the
inside of the second section.

On external fed cables, the cable passes through pulleys or guides
about 1 foot from the bottom of the second mast and goes through the
mast from one outside edge to the other. On internal fed cables,
usually only one pulley or guide is used about a foot from the bottom
and the cable passes through the guide and up to the top of the third
section where a guide or pully like unto the second section is
installed.

The cable from the last section is fed to the winch.

Needless to say, crank-ups need spacers (bushings) to make way for the
cable, so you have to start with larger diameter tubing for the base
than on push-ups and work in skipped increments of pipe sizes.

I saw something interesting about 3 years ago, a crank up made from a
normal push-pole that used a relocatable gear drive instead of cables.
I don't know how much weaker it made the push-pole, but it was guyed,
so I guess it really didn't matter too much.

The fellow took a standard 50 foot push pole and drilled 1/4 inch
diameter holes along the length of each section, except the top two,
which are easy to push-up anyhow. Then he had a winch like device
that had a large cogged gear that affixed more akin to a gin pole, on
the mast below the one being cranked up. Once extended, the clamps
are tightened and the winch moved down to the next section below the
one being cranked up. The guy wires were measured and attached, so
when the last section was cranked up, they all reached a certain
tautness, that was later adjusted to the proper tension.

There is one I would have like to find the workings of. It used water
from a garden hose, rather than a winch, to raise the pole. Yet no
water remained in the pole after it was erected. I don't know if
water was used to drive a winch or if it worked on hydraulics. I
wasn't that close to it to see. I do know that the top section raised
first and was pinned with a pin and spring. Then the second section
was raised and pinned. Too many people around to get near the base to
see what was going on and I never saw it advertised anywhere after
seeing it. I sorta doubt if it was hydraulic though, as the water
pressure would have to be much greater than what a garden hose can
supply. And it seems water would be spurting out the pinning holes.

Still, it's something to keep pondering on!

TTUL
Gary

  #2  
Old September 11th 03, 07:39 PM
Tarmo Tammaru
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Default

How did you keep the inner sections from rotating?

Tam/WB2TT


 




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