[TowerTalk] Tilting Down a US Tower HDX-589MDPL
J D Lambright
jdlambrightatty at gmail.com
Sun Mar 1 12:42:41 EST 2015
I really appreciate all the responses to my question a week or so ago.
Several of you have requested details and pictures of the motorized setup I
am using to raise this tower.
I'll provide the details here, then forward pictures to those who have
requested them.
The tower raising fixture is a US Tower TRX-80HD. Rather than using the
standard manual winch, the motorized raising mechanism I am using is
mounted on heavy steel and then welded to the TRX-80HD.
The worm gear drive is a Hub City W300 50:1 ratio speed reducer. The motor
is a 1 HP (115v / 230v) thermally protected farm motor made by GE (Cat No.
F10E1). It turns at 1,725 rpm, and I'm running it off of 115v.
I made the motor mount is a 1/4 inch thick, 12 in. x 12.in
. aluminum plate. The aircraft cable used for lifting is 1/4 inch. The 4
sheaves (2 ea. on the tower and 2 ea. on the raising fixture) result in a 4
to 1 mechanical advantage.
All of the coax, rotator cable, 115v cable, coax switching control cable,
etc. are running underground in 3 electrical PVC conduits ( 2 ea. 2 1/2 in.
and 1 ea. 1 1/4 in.) from my ham shack about 50 feet away. I have the
exact same setup on a 2nd tower 125 ft. away from this one.
So I can stand back from the tower for safety purposes when raising, I am
controlling the motor using a 3PDT pendant switch on a 12 ft. cable. That
switch, a 2-button momentary push switch (up-off-down), is from KH
Industries (CPA02-A4C-000A). I used a 7 conductor trailer connector
(Hopkins Towing Solutions #48470 7 blade) to connect the 3PDT switch cable
to the lifting motor plate. The matching female connector (I forget the
#) is attached to the other end of the cable. That way, I can disconnect
the pendant switch assembly and take it inside when not in use. I will be
using this same pendant switch assembly on the motorized mechanism that
telescopes the tower to 89 feet.
In the Hub City drive, I'm using Mobil SHC 634 synthetic gear & bearing oil
(ISO VG 460) as recommended by Hub City.
This setup slowly and smoothly raises my US Tower HDX-589MDPL (approx.
2,500 lbs.) from horizontal to vertical in about 4 minutes.
Let me know if I can provide any additional information.
J D Lambright KF5U
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