Made Cowl Flap Linkage using 6061 T6 0.3130 O.D. aluminum tubing with a wall thickness of 0.0580 x 11.5" length. Progressively drilled out the tube center to a final #3 drill size. Tapped both ends for a 1/4" x 28 thread. To the top of the linkage, I attached a CM-4S Aurora Rod Bearing with a 1/4" thread on both the bearing and the rod end. On the cowl flap end, I attached a MM-4 Aurora Bearing that has a 1/4" center hole that will be filled by Clevis Pin to secure the flap to the linkage.
Made brackets to attach the linkages to the cowl flap using 3/4" pieces of 3/4" aluminum right angle stock. Two pieces were used for each linkage and they were match drilled with a 1/4" hole for the Clevis Pins.
