Question

if the feed per revolution on an upright drilling machine is set to 1/64" and the rpm is set to 105, how many revolutions are required for the drill to advance 2 1/8" into the part?

Answer 1

Answer:

Proportion states that the two ratios or fractions are equal.

As per the given statement:

f the feed per revolution on an upright drilling machine is set to 1/64" and the rpm is set to 105.

Let x represents the revolutions are required  for the drill to advance $2\frac{1}{8}" = \frac{17}{8}"$ into the part.

By definition of proportion:

$\frac{\frac{1}{64} }{105} = \frac{\frac{17}{8} }{x}$

By cross multiply we have;

$\frac{x}{64}= 105 \cdot  \frac{17}{8}$

Multiply both sides by 64 we get;

$x = 105 \cdot 17 \cdot 8$

Simplify:

$x = 14,280$

Therefore, 14,280 rpm revolutions are required for the drill to advance $2\frac{1}{8}" = \frac{17}{8}"$ into the part