Question

In a quick return motion mechanism of a Crank and slotted Lever type the ratio of maximum velocities is 2

Answer 1

$(a)\ \dfrac{x}{25} = 2$

$x = 50\ cm$

$(b)\ \sin\dfrac{25}{50}= \sin({90-\dfrac{\theta}2)}$

$30° = 90 -\dfrac{\theta}2$

$\theta= 120°$

ratio of time of cutting to return strokes = $\dfrac{180-\theta}{\theta}$

$(c)\ 30\ rpm × 2 = 60\ rpm$