well i did start that but soon realized i would have to buy another controller to fire it on command then i had a vision (actually i tripped over my RC nitro car then it came to me RC-carmageddon so with some parts that i had sitting round i figured i could do this for only the price of the rocket
the link for the video can be found here
vid number 2 firing a small screw
Step 1: What you will need
>>>>>>>Remote controlled car (working would help)
>>>>>>>4 Channel or more the better controller and receiver
>>>>>>>Higher capacity battery's (I use a heli lithium cell 7.4v 800mah)
>>>>>>>2X RC servo
>>>>>>>TOOLS and MATERIALS:
Screwdrivers small and large phillips and flat head
Aluminium off cuts
Step 2: Lets get this party started
you will then need to fashion a mount out of your aluminium or whatever you have around.
Step 3: Turret construction
start by removing one of the servos bottom casing, when the casing is removed look at the construction of the servo for some free space inside for the head of the screw and drill a hole in each side of the servo and make the one opposite the mounting hole big enough to fit your screw driver in to tighten.
attach the casing to the second servo and tighten then put the first servo together, after that attach to the mounting on the car that you attached earlier.