Question

During a conventional milling operation, if depth of cut gets doubled where as the cutter diameter reduces to half, then what will be the percentage change in maximum uncut chip thickness ?

• A. 0 %
• B. 50 %
• C. 100 %
• D. 200 %

Answer 1

The correct option is C 100 %

Maximum uncut chip thickness,
$t=2f_t\sqrt{\frac{d}{D}}$
Where, $f_t$ is the feed per tooth of the cutter that is, the distance the workpiece travels per tooth of the cutter, in mm/tooth
Where, d = depth of cut,
D = cutter diameter
So, $t\propto \sqrt{\frac{d}{D}}\frac{t_2}{t_1}=\sqrt{\frac{2d}{D/2}}\times \sqrt{\frac{D}{d}}=\sqrt{4}\frac{t_2}{t_1}=2\Rightarrow t_2=2t_1$
Percentage change
$=\frac{t_2-t_1}{t_1}\times 100=\frac{2t_1-t_1}{t_1}\times 100=100\%$