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@oltraining.com>
To: <towertalk@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@contesting.com"
> <towertalk-request@contesting.com> wrote:
>
>> Message: 2
>> Date: Tue, 21 Oct 2008 21:37:22 -0400
>> From: "Bill Gaines AD8P" <ad8p@wcoil.com>
>> Subject: [TowerTalk] LM-470 Installation Info Needed
>> To: <towertalk@contesting.com>
>> Message-ID: <00b601c933e6$bb2c3120$6501a8c0@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
>
>
> _______________________________________________
>
>
>
> _______________________________________________
> TowerTalk mailing list
> TowerTalk@contesting.com
> http://lists.contesting.com/mailman/listinfo/towertalk
>
>
> --
> No virus found in this incoming message.
> Checked by AVG.
> Version: 7.5.549 / Virus Database: 270.8.2/1738 - Release Date: 10/21/2008
> 2:10 PM
>
>
_______________________________________________
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
|