A servo would be a poor choice for an elevator and require complex control circuitry. A reversible DC motor and limit switches on each floor would be better IMO.
A servo would be a poor choice for an elevator and require complex control circuitry. A reversible DC motor and limit switches on each floor would be better IMO.
At the risk of been boring, an 8 pin PIC could be easily programmed to do the task - and is small, cheap, light, and easily configurable. If you choose one with analogue inputs, you could use preset resistors to manually set the two servo points.
To do it with 555's would take three 555's, and much more circuitry.
PICs and any microcontroller make for terrific timers, BUT you'll need a programmer & some programming skills. PICBASIC Pro has a free 40 line limited version with support for the tiny 8pin 12F683 that should be plenty for a 5 second delay with servo pulse stream. Far more flexable than any 555 version.