Guys,
I am working on a new project and need to move a full flying stab...................no big deal but after thirty plus years of flying and not paying attention to servo ratings very much can someone explain the meaning of oz/in. I realize that a 100 oz/in servo is more powerful then a 50 oz/in. ................but what does it mean? Is it the ability to move 50 ounces, one inch in one second or what? That said anyone familar with the JR 4721 or JR 8711 servos;
Thanks,
Glenn

I should have paid more attention in physics class

10oz/inch means, the servo can 'push' with a force of 10oz, one inch from the center of the servo-arm. (which means 5 oz 2 inch from the center of the arm, or 20oz 1/2 inch from the center of the arm)

Shameless copy-paste from another website:

The torque rating specifies how much force the servo can exert. It is typically expressed in units of ounce-inches (oz-in) or kilogram-centimeters (kg-cm). The higher the number, the more force the servo can exert. If you know the length of the servo arm that will be used, you can use this measurement and the servo torque rating to calculate how much force end of the arm can exert. A long arm will reduce the maximum possible force, and a short arm will increase it.

Yep, you should also note the holding power (important with big flying stabs that have to stay in a set position) and gear types.
A Comp ARF Hawk uses 2 x 8711 on one stab, this helps reduce linkage slop, increase holding power and you cannot over power a surface..you can underpower them!

Dave W