[TowerTalk] Anyone Using a Fulton KW3000 Winch with Powerful 1/2 inch Pistol Drill for tower tilting ?

[Roger (K8RI)]

It seems like this is a bit complicated.  Were it me, I'd remove the 
hand crank and install an adapter for the drill motor.  The hand crank 
should not turn hard, if it does the gear ratio is wrong. If the hand 
crank turns easy there should not be a tremendous load on the drill 
motor.  OTOH those drill motors are designed for *Intermittent* use and 
will get hot after 30 seconds to a minute of use. Unfortunately they are 
not designed with adequate cooling for heavy duty work like the old ones 
were.  I used a heavy duty Craftsman (the old one with the all metal 
case)  1/2" to power a tug to pull a 3100# airplane in and out of a 
hangar and down about a 100' ramp. This meant about 2 minutes of 
continuous use.  It would never get warm. OTOH the brushes finally wore 
out and created a bit of fire works. <:-))  We brought the filed 
windings out and to a switch on the long handle so it could easily be 
reversed.

Kevin Normoyle wrote:
> given
> -the weight of the tower
> -the length of the tower
> -the weight of anything else on the tower (winch, rotor, bearing, mast 
> antenna)
> -the height of the pulley on the raising fixture
> -the attach point to the tower
> -the distance of the raising fixture from the tower pivot point
>
> it's pretty easy to compute the pulling force the winch sees at the 
> drum...(statics/moments..translate uniform loads (the tower) to 
> equivalently placed point loads, and work out the forces from the angles)
>
> Then the gear ratio, and drum radius vs handle radius ratio, can give 
> you mechanical advantage results?
> (with a drill setup being a negative ratio since the shaft radius is 
> less than the drum radius?0
>
> Assuming you don't use anything to get the tower the initial couple of 
> feet off the ground, then the hardest pull is right off the ground, so 
> just have to calculate that case.
>
> My question: If the lift is so hard, it makes me wonder if it's rigged 
> as a single line pull...i.e. not a double line compound pulley setup.
> Also, how short is the raising fixture?
>
>   
That would make sense. I use double line on everything that tips or 
folds over here. I don't have anything really large, but a 40' 25G 
hinged at the base with the AV-640 on top makes for quite a pull.  OTOH 
I can now raise and lower the thing by my self.

73

Roger (K8RI)
> Short raising fixture + single line pull....very hard. (might be over 
> 3000 lbs?)
> If it's not a double line pull, then that would be the easiest thing to 
> improve the situation.
>
> -kevin
> ke6rad
>
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