I think I can say this is our first assignment that is close to practical designing.

Preliminary design of a winch lift.
Determine the force-time function in the lifting table, the necessary drum diameter, and the torque-time function acting on the shaft of the winch drum during any 1 cycle. Define the gear ratio and the power and torque requirements for the motor.

GIVEN:
A hay bale’s weight varies depending on its moisture content but can be assumed to average about 60 lb. The hay truck holds 100 bales and the framer would like to unload it in 30 min. The lift height is 24 %.

ASSUMPTION:
Nylon rope of ¾ in diameter has minimum break strength of about 8000 lb and spring
constant of about 50000 lb/in per % of length in axial tension. Design of a worm set speed reducer for a winch lift. Size the worm and worm gear for the winch life in defined above. Design it.

GIVEN:
For an assumed winch drum radius of 10 in, the peak torque will be about 7800 lb-in, the average output power required was calculated to be 0.6 hp. A 75:1 reduction is required. Input speed to the worm is 1725 rpm. Output speed is 23 rpm.

ASSUMPTION:
A single start worm with a 20 degree pressure angle will be tried. The worm will be a steel case hardened to 58HRC and the worm gear of chill cast phosphor bronze. A self-locking worm set is needed.

Less than one month due from now and we didnt even start solving yet.

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Just back from playing basketball. Whole body is generating heat from the inside even when I havent start playing. Weather is so friggin hot I guess.

I need ICE!