Do you really want to control the speed of servo-motor?

Or do you want to control speed by means of a servo-motor?

What is your servo-motor like?

I'm sure that a quick search on google will reveal ample information...

Lots of projects have already been published on the internet.
Anyway, if you will want an answer on this forum, some information is required...

A precise question will most likely trigger a precise anwer.

rgds
Patrick