I will make this in 2 parts...
The first part is the actuall turret and how orb made it.
The second is how to make a Cam Controller Look where the Turret looks and also make it from stop spinning when it has no target.
Okay lets start. You will need some basic knowledge about wiremod for this..
First you need 3 phx plates:

Axis the bottom one to the middle one without friction and ballsocket the top one to the middle one so it can tilt up/down left/right:

note: The ballsockeded one can glitch abit and tilt to left/right, if it do that way to much redo it...
now tilt the ballsocked plate 45 degrees against you so the both ballsockets is away from you.
Then spawn a beacon sensor with Bearing checked. Also a target finder and link it.
Spawn it at the front:

Now we need 4 gates and one constant value.
A Time -> Accumulator
A Logic -> Or(all)
A Comparison -> Greather than
A Comparison -> Less than
and a constant value with 75:
Place them like this or as you want...

Wire:
Accumulator A -> Beaconsensor Elevation.
Accumulator Reset -> Or(all)
Or(all) A -> Greather than
Or(all) B -> Less than
Greather than A -> Accumulator
Greather than B -> Constant value
Less than A -> Accumulator
Note: Less than B shouldent be wired cus the default is 0 and that is what we want.
Now make a hydralic Between the top 2 plates (non fixed)

Then wire that to the accumulator.
Okay now we got the up/down movement. Lets go for side/side
Spawn:
A arithmetic -> delta
2 arithmetic -> multiply
A arithmetic -> add
A constant value with 2 values: 10 and 2.

Wire:
Delta -> Beaconsensor bearing
Multiply1 A -> Beaconsensor bearing
Multiply1 B -> Constantvalue 2
Multiply2 A -> Delta
Multiply2 B -> Constantvalue 10
Add A -> Multiply1
Add B -> Multiply2
now we got that. now for the thrusters.

Remember Force multiplyer of 7.
Maximum force: 99999
Minimum force: 99999
And also remember Bi-directional!!
Wire them to the Add chip.
Kay now we got the movement!
lets add some weapons!!
add a ranger with like 99999 length, show beam, and ignoreworld
and add a turret with no spread and settings is yours
wire the turret to the ranger.
Now part1 is done!
lets go for part2
We start make the Cam controller.
place a GPS little above the phx plate (see the picture) Then spawn a gyroscope under it.

Now place the cam controller on a workdesk or something combined with a chair and a adv pod controller:

Link the adv pod controller and the cam controller (actually i will call the cam controller CC) to the seat.
Wire Active of the CC to the Advpodcontroller of Mouse1 or something but you can also choose active so you will always look trough the CC.
Wire X, Y and Z to the GPS.
Wire Pitch and Yaw to the Gyroscope.
Note: Not the roll.... it will mess up then
Another Note: if you want the cam to be upside down. wire Roll to a constant value of 180.
If the CC is looking at the wrong direction. Turn the gyroscope around untill its right.
Now when you press Mouse1 you will look what the turret is seeing.
Now for the anti-spin function.
Make a weld latch between the 2 bottom plates.
place that on the top plate.
Place a comparison -> Equal gate besides it
Wire the Equal to the targetfinder -> 1
Note: not 1 [blablabla]
then wire the weld latch to the Equal.
this makes the weld latch to be on when it has no target and viceversa.
Well guys that was all from me this time! Cya!
Ask so much you want and say anything i should improve for the next tutorial