I don't know how you are driving the servo's PWM signal (CPU etc) but I had the same problem with my camera base. On my system I improved it by using two voltage regulators (One for ATMEL CPU/Network card and one for the Servo's).
In the end I stopped the servo's hunting but switching off the interrupt that drove the servo's 3 seconds after getting the last position change command. The servo's I'm using have enough friction and the camera is so light that the whole construction doesn't move.
Regards Ian Dobson
Home of the Atmel based UDP mobile web cam
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"HAS2BOKwithoutspam@H..O..T..M..A..I..L.....C..O..M" schrieb im Newsbeitrag news: firstname.lastname@example.org... I'm building a camera pan & tilt mechanism to hold a webcam for motion detection. I've used 2 hitec hs-311 servo's attached together by homemade brackets. The system does basically work but I need some advice as it's my first experience with RC servo's (bought from ebay @ £4 sterling each).
The servo's move as commanded but after reaching their demand position they drift/hunt. I expected a little of this but not as much as is occuring. Even without the load of a webcam there is still obvious hunting.
Is this common to all cheap servos? Any way to decrease the error?
The only thing I can think of is to rebuild the pan & tilt using gears to introduce some backlash/play to compensate for the servos.