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Re: [TowerTalk] Tower winch failure

To: richard@karlquist.com, "Dino Darling" <dino@k6rix.com>
Subject: Re: [TowerTalk] Tower winch failure
From: Jim Lux <jimlux@earthlink.net>
Date: Sat, 17 Mar 2007 16:09:39 -0700
List-post: <mailto:towertalk@contesting.com>
At 03:27 PM 3/17/2007, Rick Karlquist wrote:
>Two questions:
>
>1.  I have an HDX5106 with a 2550.  I feel that this winch is
>overloaded, in the same way that the guys with the "little" towers
>feel their 1550s are overloaded.  Is there something even bigger
>than the 2550 I can convert to?
>
>2.  I realize these winches have an enviable track record, but
>why should I want to fool with a winch having a "squeeler" brake
>as opposed to a worm drive winch?

Money??
BTW, while for most worm drives you can't "back drive" them, for some 
you can. It depends on the worm gear pitch and tooth shapes.

>  Worm drive seems much more
>logical to me.  What I would really like to do is get worm drive
>winch that is geared down another factor of 5 or 10 compared to
>the 2550 and then use an electric drill on the shaft.

I would imagine that you can get such a thing from a place that does 
machinery. You can buy an off the shelf worm/pinion reducer for 
whatever ratio you want (100:1 isn't unusual), and then couple that 
to a cable drum.  They also make nifty little "anti runaway" clutch 
widgets that rely on centrifugal force to  engage a brake when the 
rotational speed gets too high.

I offer the following mechanical ideas for folks who want to think 
about "other ways to do it"..

1) Hydraulics!  A 5 HP motor is about the size of an apple, and are 
ideal for low speed, high torque applications.  You use a low 
displacement unit on your electric motor (which spins fast) and a 
high displacement unit on your cable drum (which spins slow).  Et 
voila, hydraulic gearing! (you'd probably still need some sort of 
spur gearing.. there IS a limit on practical ratios just with 
hydraulics) You can limit the speed at which it travels in one 
direction with a check valve and bleeder (a standard item for hydraulics)

2) The things that they use for belaying on those portable climbing 
walls.  Basically, a bunch of passes of the cable back and forth 
between a multi sheave pulley, with a hydraulic cylinder to limit the speed.

3) Counterweights... they work for elevators, they can work for you 
too (especially with the multi part block and tackle scheme described 
above, so the cable movement is 5-6 times the movement of the 
counterweight..)  This is especially convenient if you have a spare 
multi thousand pound counterweight around. (e.g. a cubic yard of 
concrete weighs several thousand pounds)


All of these will potentially be more expensive than a few hundred 
bucks for an off the shelf winch from Fulton, etc.  However, if you 
happen to have some of the parts around, perhaps not.


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