Servo MG995

I have problem to control Servo MG 995. I’m a dunny could someone please help me?
I have three cable two of each for power supply and 1 for control. I connect the servo to a 12 V Dcc and the other one? I tried to connect to a NE555 with a duty cicle of 0,5 sec and I found a quater of 360 and come back. I need to make aorund three 360 and come back! The voltage of the control at the moment is around 5 V. :frowning: Could you please help me?

You may refer to this:, or this