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?
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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