"Karl Townsend" wrote in message
news.com...
For only about 90 degrees of motion you don't need the rack. just use the
crank shaft - connecting rod rod type idea. That is, an air cylinder connected
to a shaft with a lever arm. A short lever arm makes for very fast motion,
less torque.

Karl



This is looking to be the best option. I talked to a couple of "Rotary
Actuator" manufacturers and they both balked when I told them I needed 250 ms
half-cycle time. One second seems to be their comfort zone.