Question

A gear with $84$ teeth is to be machined usign a milling process with indexing. The index plate has the following four hole circles: $36,38,42,48$. The change gear ratio required is

• A. $8/21$
• B. $10/21$
• C. $21/10$
• D. $21/8$

Answer 1

The correct option is B $10/21$

$N=84$
$CR=\frac{40}{84}=\frac{10}{21}$