surepic:
Well, if this idea wont work then i will put arduino nano or micro and will forget about 555 forever :-))Mike why you were driving servo via fet instead of mosfet? Isnt it more efficient in this shcematic to use mosfet? Something like 2n7000?
I'll take a stab: first I'll assume you mean bi-polar when you wrote fet. If so, then:
Based on the 4k7 pull-up, that servo doesn't require much current to drive it, thus bipolar vs MOSFET is trivial, since power loss is trivial.
BTW: a 2N7000 is not a good choice for 5V switching. More like 2N7002, or even VN2222LLG