Lessons Based on Merchants Equation

Q.

Common Data:
A cylinder is turned on a lathe with orthogonal machining principle. Spindle rotates at $200rpm$. The axial feed rate is $0.25mm$ per revolution. Depth of cut is $0.4mm$ The rake angle is ${10}^o$. In the analysis it is found that the shear angle is ${27.75}^o$.

The thickness of the produced chip is

1. $0.511mm$
2. $0.528mm$
3. $0.818mm$
4. $0.846mm$

Q.

Common Data:
A cylinder is turned on a lathe with orthogonal machining principle. Spindle rotates at $200rpm$. The axial feed rate is $0.25mm$ per revolution. Depth of cut is $0.4mm$ The rake angle is ${10}^o$. In the analysis it is found that the shear angle is ${27.75}^o$.

In the above problem, the coefficient of friction at the chip tool interface obtained using Earnest and Merchant theory is

1. $0.18$
2. $0.36$
3. $0.71$
4. $0.98$