uArm base bearing

I use .177 Cal. (4.4 mm) bbs from walmart for the bearing takes 28 balls to fill it. innerRing-B is the bottom, attaches to the base of the uArm (3 holes). innerRing-A is the top, attach the horn to it. might have to shim the servo up a bit to achieve right clearance.
Assemble the whole bearing first. Use long bolts #6 x 1.5" to go through square base.