Hello Friends - I don't think this question actually requires a mechanical engineer but I'd like to get this right the first time.
Here's the question: I am putting up a 50 foot tower. 50 feet includes the height at the antenna. The tower I am using is very light weight. It is made by Universal Tower. I want to put an anchor pole next to the tower to mount a 12 volt winch. The Specifications of the winch: 12V, 2000 Lb pulling capacity, 6000 Lb rolling capacity (CB) 30 foot steel cable. The tower, I am estimating, weighs about 100 pounds with antenna and rotor.
My question is: Should I use a pulley system like this: http://www.fighter411.com/N1TKO07/tower1.gif
or will I have to use a 2:1 ratio pulley setup. Also, at what height on the anchor pole should the winch be located? Keeping in mind that I only have 30 feet of cable on the winch.
I hope I am not "over killing" this project, but I just want to get it right the first time.
Any help sure would be appreciated.
Thanks in advance.
Jerry - N1TKO
Mechanical Engineer?
engineer
first off the maximum lift weight would be 100 lbs if lifted from the top.
In any case some of the weight will always be born by the tilt base.
first class lever = fulcrum in the middle
second class = fulcrum on one end, effort arm longer than rersistance arm.
third class = fulcrum on end. effort arm shorter than resistance
so the tower becomes a third class lever..
you can calculate the lift effort required using simple math as the emchanical advantage is directly proportional to the ratio of the two arms.
IE. if your pull point is half way up the tower, the lift required is about 200 # discounting the amount born by the tilt base. which varies as the tower is raised.
it puts you in the ballpark as it is obvious you dont need 1000# of lift at the center point, only about 200.
In any case some of the weight will always be born by the tilt base.
first class lever = fulcrum in the middle
second class = fulcrum on one end, effort arm longer than rersistance arm.
third class = fulcrum on end. effort arm shorter than resistance
so the tower becomes a third class lever..
you can calculate the lift effort required using simple math as the emchanical advantage is directly proportional to the ratio of the two arms.
IE. if your pull point is half way up the tower, the lift required is about 200 # discounting the amount born by the tilt base. which varies as the tower is raised.
it puts you in the ballpark as it is obvious you dont need 1000# of lift at the center point, only about 200.