how to solve 6

Question

3.2. Calculate the power consumed by the following: 3.2.1. Lathe operation during which the cutting force applied to the cutting tool is 1000N and the rotational speed of the workpiece with a diameter of 350mm is 350r/min. 3.2.2. Shaper operation involving a cutting force by 750N and a stroke length of 120mm long taking 8 seconds to complete.

Answer 1

3.2.1)

The cutting force F = 1000 N

Workpiece diameter D = 350 mm = 0.35 m

Radius r = 0.35/2 = 0.175 m

Rotational speed N = 350 r/min.

 

Torque T = rF = (0.175)(1000) = 175 N-m

 

Power P = 2πNT/60

P = 2π(350)(175)/60 = 6414.085 W

The power consumed is 6414.085 W.

Answer 2

3.2.2 )

Stroke length x = 120 mm = 0.12 m

Work piece cutting time t = 8 sec

t = 8/60 = 2/15 min

Cutting force F = 750 N

Speed  N = Stroke length / cutting time = x / t

N = 120 / (2/15) = 120*15/2 = 900 N

 

Torque of machine T = xF = (0.12)(750) = 90 N-m.

 

Power P = 2πNT/60 = 2π(900)(90) / 60 = 508938.01 = 508.94 kW

The power consumed is 508.94 kW.