For those of you interested in the ultimate. Also note the slick micro-size lock nut in the picture below. It is a metal 4-40 lock nut about half the size of the lock nuts that come on these high-end ball links. It is available from Microfasteners, is way better than the supplied lock nuts or those that come without a locknut at all, and comes in several micro sizes. Unfortunitely the below site desn't have a pic, but the below is good as you probably can see.

http://www.microfasteners.com/catalo...cts/NUTLNM.cfm


PS on Toms comment: One thing I had failed to concider that will reduce the torque forces,is how much the arm needs to move in the up and down plane. If it is minimal, you can remove the spacer plate just below the ball and replace it with a micro washer, reduce the torque on the servo and still have the movement you need.