Question: If you have one of those gizmos that transforms rotational 
motion to reciprocating motion, what path does the reciprocating part trace?

Answer: As far as I can tell, the path is

   cos a + Sqrt(k^2 - sin^2 a)

where k is the length of the connecting rod that is free to pivot. As 
you can see, that means that for large k, the path is approximately a 
sine wave. However, for small k it deviates significantly from a simple 
sine wave...

Post a reply to this message