[TowerTalk] TowerTalk Digest, LM-470 Installation Info Needed

[Al Williams]

My two LM470 towers were purchased several years ago (Just after Triex 
decided to stop making them) so the design might have been changed?  I also 
had a HDX572 tower for comparison--both with their raising fixtures.

The HDX had a two pulley bracket welded to the tower up about 8' from the 
bottom of the tower whereas the LM470 Mfr furnished
a temporary bracket for one pulley and a cable "sling" to temporarily bolt 
the bracket to the tower up also about 8' from the bottom.

The HDX had two pulleys mounted at the top of their raising fixture whereas 
the LM470 had only one pulley at the top of its raising fixture.  The cable 
from the winch was strung up thru one of the raising fixture top pulleys, 
then over thru one of pulleys in the weleded fixture and back thru the other 
pulley at the top of raising fixture, back thru the other pulley on the 
welded fixture and then
bolted to the top of the raising fixture.  The mechanical advantage was from 
four pulleys (or is it only three?).  Whereas, the LM470 cable from the 
winch went up over the pulley at the top of raising fixture (no mechanical 
advantage) and over thru the sling mounted pulley, then back to the top of 
raising fixture and bolted.  A mechanical advantage of only one pulley.

The HDX system was permanent and used afterwards for both tilting the tower 
back down and up.  However the LM470 system was temporary and only used to 
tilt the tower up once.  The towers two leg ears were bolted to 
corresponding ears at the top of the raising fixture so that the tower 
became like a teeter/totter although highly imbalanced.  The bracket and 
sling was removed and discarded.  The pulley from the sling bracket was 
installed in a bracket welded down at the bottom of the raising fixture. 
The cable from the winch was then strung down, thru the bottom pulley and 
bolted to the bottom of the tower.  No pulley mechanical advantage.  Only 
the benefit of the tower pivoting about 8' from the bottom of tower at the 
top of the raising fixture.

I was apprehensive about recabling the LM470 into the no mechanical 
advang\tage pulley system and hoping that everything would be ok on the 
first tilting back down so I modified the LM470 to be similar to the HDX 
system.  Was I too cautious and is the teeter/totter action quite 
satisfactory?

FYI The brake winches furnished have a "free wheeling mode" that can allow 
the wieght of the tower to freely pull the cable out of the winch.  It can 
be stopped by grabbing the winch handle at the risk of injury.  The brake 
winch goes into the free wheeling mode when the load is removed from the 
winch and the drum turned a bit.  It is necessary to tighten the winch from 
this free wheeling mode in order to "latch?" the brake which then holds the 
tower.  Fortunately I discovered this mode while the tower was just 
beginning its free wheeling trip to the ground and I was able to grab the 
handle when it was turning slowly.

k7puc



----- Original Message ----- 
From: "Terrence R. Redding Ph.D." <terry at oltraining.com>
To: <towertalk at contesting.com>
Sent: Wednesday, October 22, 2008 7:29 AM
Subject: Re: [TowerTalk] TowerTalk Digest, LM-470 Installation Info Needed


> Bill, do you have the raising and tilting fixture?
>
> I seem to recall that you use the same pulley in the upper position to 
> raise
> the tower and the lower position to tilt the tower.
>
> First, with the pulley in the upper position, to lift the tower from
> horizontal to vertical within the fixture, bolt the pivot points of the
> tower to the fixture, and then reposition the pulley from the upper 
> position
> to the lower position.  From the lower position the pulley controls the 
> tilt
> of the tower.  But it is the same pulley.
>
> Terry - W6LMJ
>
>
> On 10/22/08 12:29 AM, "towertalk-request at contesting.com"
> <towertalk-request at contesting.com> wrote:
>
>> Message: 2
>> Date: Tue, 21 Oct 2008 21:37:22 -0400
>> From: "Bill Gaines AD8P" <ad8p at wcoil.com>
>> Subject: [TowerTalk] LM-470 Installation Info Needed
>> To: <towertalk at contesting.com>
>> Message-ID: <00b601c933e6$bb2c3120$6501a8c0 at bille2035267a6>
>> Content-Type: text/plain; charset="iso-8859-1"
>>
>> I have my "new-to-me" LM-470 bolted to the raising fixture and resting in 
>> a
>> horizontal position. I have been looking at the manual I have and it says 
>> to
>> run the raising cable up thru the upper pulley on the raising fixture 
>> then
>> down to the tower thru a 4" pulley and back to the original pulley on the
>> fixture. The drawings show a sort of bracket that is holding this pulley 
>> and
>> the bracket encompasses the pulley in such a way it would be nearly 
>> impossible
>> to bind up. I don't think I have this bracket. I have 2- 5" pulleys but I
>> thought they would mount on the raising fixture. I also have a few
>> extra-but-used 3.5" pulleys and no bracket. Do I need this bracket? Or 
>> can I
>> simply put a bolt thru the pulley and use the small cable assembly that 
>> came
>> with it to loop around the tower leg to secure the pulley to the tower?
>>
>> I just wanna do it right so I am asking.
>>
>> Bill AD8P
>
>
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