A couple of additional comments on tower sections sticking when lowering.
1. My TX472 had fairly tight fitting angle guides on the top section and
that was the one which would sometimes stick. I increased the clearance by
using a steel rod and a small sledge hammer to bend the ears of the angle
which guides the corner tubes. When the tower is horizontal it is easy to
push the sections back and forth to be sure there is significant clearance
at the guides.
2. The sticking is worst when there is a side wind blowing and
,unfortunately, that is exactly when you usually want to lower it. If I was
using a remote control system I would try very hard to not lower when the
wind is blowing.
73, Dan, N5AR
-----Original Message-----
From: towertalk-bounces@contesting.com
[mailto:towertalk-bounces@contesting.com]On Behalf Of Bill Kerns
Sent: Thursday, July 10, 2008 9:45 AM
To: andersonww5l@sbcglobal.net; towertalk@contesting.com; NPAlex@aol.com
Subject: Re: [TowerTalk] WT-51 remote/winch
Thanks for all the inputs/suggestions. They are much appreciated.
I already have emailed Karl about motorizing the WT-51, but have not yet
heard back from him.
I am still trying to develop a concept for a positive pulldown mechanism
with electric winch. However, I am also planning to add some extra safety
features (based on everyone's safety concerns expressed), such as power
interlock and cameras and lights to ensure that I can see the sections as
they come down remotely.
Once I develop a concept and validate that it works, I will share it on
TowerTalk.
I am also still looking for a good schematic for a remote control unit, with
relays, time delays, etc. which can be activated remotely with a couple
control wires. If anyone has a good schematic (with parts list), it would
save me some time.
-Thanks,
Bill, N6DAG
Bill:
When I bought my W-51 in 1992 from TriEX I asked their
then sales mgr. Mike Feryan, who I ran into at Dayton
this year, about motorizing it. He said that tower
was never designed to be motorized. If I find his
business card, he works for another company now since
TriEx itself went out of business, I'll give you his
e-mail address. Or better yet, if you'll e-mail Karl
Tashjian at Tashjian Towers (contact e-mail should be
on their website) he can tell you exactly. Karl was
the Califnrnia engineer who was one of the designers
of the W-51 and his "wet stamp" is on the engineer
drawings I received when I bought by W51 in 1992.
Karl now ha "sort of" revived the old TriEx line of
towers.
Tom, WW5L
--- NPAlex@aol.com wrote:
> Bill,
> The cautions that you have received are very real
> potential problems when
> motorizing a crank-up tower. Although I have not
> worked with the Tri-Ex WT
> series, I have motorized, and remote controlled
> several Tri-EX LM-470 towers,
> and currently have a US Tower HD-589 that has the
> remote feature.
>
> The RMC-1000 controller is a US Tower item, and is
> nothing more than a
> grouping of switches and indicator lights for power
> on, Remote/Local, Tower UP and
> Tower Down. It does not supply power to operate the
> winch motor, but does
> control a remote relay that does activate the remote
> control box at the tower.
> That box contains relays for UP and DWN (reverses
> the motor rotation), two
> time delay relays to prevent switching direction too
> quickly (if you don't
> delay, the motor keeps going in the same direction).
> and also interfaces with
> UP and DWN limit switches.
>
> One key issue is the winch type and drum size. The
> type should be worm gear
> driven, a ratio of about 40:1, The drum size in the
> 3 to 4 inch diameter,
> and the length must be capable of hold all the cable
> in ONE single layer. You
> can not jumble wind cable when using a positive pull
> down cable. You do need
> a long eyebolt with a very heavy coil spring of at
> least 8 to 10 inches long
> (a 51 foot tower may get away with less). This
> spring maintains positive
> tension on the down cable, and compensates for the
> normal stretch or give in
> the cables.
>
> The amount of UP cable that spool onto the drum is a
> function of the lift
> cable design - Late model LM-470 towers this cable
> went to the top of the base
> section, down to the bottom of the first moveable
> section, and then back to
> the top of the base section. This is a two to one
> mechanical advantage, and
> the amount of cable winding onto the drum is double
> the length that the first
> section moves.
>
>
> From: "Bill Kerns" <bill@billkerns.com>
> Subject: [TowerTalk] Tri-Ex WT-51 Electric Winch
> with Pulldown
> Mechanism and RMC-1000
> To: <towertalk@contesting.com>
> Message-ID: <000001c8e09e$e2570ef0$ac00a8c0@Bill>
> Content-Type: text/plain; charset="us-ascii"
>
> I recently purchased a used Tri-Ex WT-51 tower with
> manual winch.
>
> I want to install an electric winch on the tower to
> allow me to raise and
> lower it.
>
> Since the tower will be located remotely from the
> house (about 200-300
> feet), I'd also like to figure out a way to raise
> and lower it remotely.
>
>
> I have also found a used RMC-1000 remote controller
> and am considering using
> it in conjunction with an electric winch.
>
> However, I have heard that there is a pulldown
> safety issue involved with
> this tower. So I need to have a way to pull down
> the top antenna tower
> sections, as the tower is being lowered, to ensure
> that it does not get hung
> up on the way down. My understanding is that the
> WT-51 top sections may
> sometimes bind on the way down, so having this
> second cable pulldown
> mechanism will prevent that.
>
> I am considering a single winch with 2 cables wound
> in opposite directions,
> so that as one cable winds up, the other cable
> unwinds. Then I need to add
> some pulleys to route the second cable through the
> middle of tower up to the
> top section, so that when the tower is lowered,
> this cable will pull down
> the top section as the other cable releases.
> However, someone said that
> this might be problematic, since the 2 different
> cables may not wind/unwind
> at the same rate, so I also will need a spring
> mechanism to take up the
> slack as the cable winds/unwinds.
>
> I would appreciate whatever advice anyone could
> provide to help with this
> installation- such as recommended electric winch
> model part numbers,
> suggested ideas for using RMC-1000 or similar remote
> system, pulley layout,
> etc. I also wonder what the maximum distance is
> that the RMC-1000 will
> operate remotely, since there will be 200-300 foot
> separation between the
> house and antenna tower.
>
> I am also looking for a softcopy of the RMC-1000
> schematic and manual, if
> anyone has one.
>
> -Thanks,
>
> Bill, N6DAG
>
>
>
>
>
> **************Get the scoop on last night's hottest
> shows and the live music
> scene in your area - Check out TourTracker.com!
>
>
(http://www.tourtracker.com?NCID=aolmus00050000000112)
> _______________________________________________
>
>
>
> _______________________________________________
> 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
_______________________________________________
_______________________________________________
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
|