Ball connector, Ball link, probably one and the same. However, the type I was refuring to is shown on page 82 of the Tower catalog. They are Great Planes P/N GPM03840. Goldberg used to make them and possibly DuBro, also. They arn't the bolt-on type; but, the snap-on type. The reason for using them is they allow for an amount of "un-fair lead" (they allow for an amount poor alignment). They also have very low friction.

Other folks have nicely jumped in here and given further ideas on their use and set-up, thanks!

Mark DeSchane
AMA59157