Question 1:

During turning (orthogonal cutting) of a ductile alloy by a tool having a rake angle of (a) 12°,

Cutting force is 970N and thrust force is 490N, chip thickness ratio (r) is 0.4 find the following

by first drawing Merchant Circle Diagram (MCD) and then solve by using equations listed

below. Compare both results.

a. Frictional force

b. Normal force

c. Coefficient of friction

d. Friction angle

Steps:

1. Take appropriate scale for forces.

2. Draw the Merchant circle diagram (Steps detailed in the slides)

3. Calculate forces from the diagram.

4. Calculate forces from the equations.

5. Compare results obtained from step 3 and 4.

CND

Tool

Work

Work-

Chip

(b)

Tool

FIGURE 21.6 Orthogonal cutting: (a) as a three-dimensional process, and (b) how it reduces to two dimensions in

the side view