Question

The cross bar of a planner weighting 12 KN is raised or lowered

Answer 1

Answer:

The cross bar of a planner weighing 12 kN is raised and lowered by means of two square threaded

screws of 38 mm outside diameter and 7 mm pitch. The screw is made of steel and a bronze nut of

38 mm thick. A steel collar has 75 mm outside diameter and 38 mm inside diameter. The coefficient of

friction at the threads is assumed as 0.11 and at the collar 0.13. Find the force required at a radius of

100 mm to raise and lower the load.