If a shaper has a stroke length of 240 mm and number of double strokes per minute is 40 and ratio of return to cutting time is 2 ∶ 3, then its cutting speed is

Concept:

Cutting speed of shaper is given by,

 \(V = \frac{{{\rm{NL\;}}\left( {1{\rm{\;}} + {\rm{\;m}}} \right)}}{{1000}}m/min\)

Where, V = Cutting speed of shaper, N = Number of double stroke per minute, L = l ength of stroke

m = Quick return ratio = \(\frac{{{\rm{Time\;of\;return\;stroke}}}}{{{\rm{Time\;of\;cutting\;stroke}}}}\)

Given:

Calculation:

N = 40, L = 240 mm

m = \(\frac{2}{3}\)= 0.667

\(V = \frac{{{\rm{NL\;}}\left( {1{\rm{\;}} + {\rm{\;m}}} \right)}}{{1000}}m/min\)

\(V = \frac{{40{\rm{\;}} \times {\rm{\;}}240{\rm{\;}} \times {\rm{\;}}\left( {1{\rm{\;}} + {\rm{\;}}0.667} \right)}}{{1000}}\)

= 16 m/min