Shoulder Wing Root Rocker
This rocker is part of the 'SG90 Scotch-Yoke Flapping Wing Rig' kit, and you print two. The lever is 77 x 16 x 6 mm. It pivots on a shoulder post using an M4x16 screw and an M4 washer, through a 4.5 mm hole in a 16 mm boss that has a 0.5 mm raised thrust ring. The drive link attaches with an M3x16 screw and nyloc nut through a 3.4 mm hole 20 mm inboard. The wing root bolts to two M3 heat-set inserts (4.0 x 5 mm bores) at 30 and 45 mm outboard, which turns the slider's stroke into about ±37° of flap.
mechanism kit ornithopter rocker-arm