RE: Glider cradle causes tow plane instability
I use this mailing tube to drop 6 ping-pong balls, one at time, from a Yard Stick.
The release servo is on channel 5.
The ball to be dropped rests against the release wire.
When the servo moves that wire out of the way, another wire gets pushed between the ball to be dropped and the next ball in line.
When the ball is dropped, and the servo returns to 0, the wire that held the next ball is removed, and that ball moves into the drop pocket for the next drop.
Without the air vent, the balls tended to stay in the tube until I climbed the airplane.