Yoke Slide Retainer Strip
This flat 12 x 56 x 3 mm strip is part of the 'SG90 Scotch-Yoke Flapping Wing Rig' kit, and you print two. Each one bolts across the top of a spine slide-channel wall with two M3x8 socket head screws into M3 heat-set inserts. The screws go through 3.4 mm holes spaced 40 mm apart, 8.4 mm in from the inner edge. The strip hangs 4 mm over the slider's edge band so the slider can't lift out. It has 3 mm radius ends and a 0.4 mm chamfer on the inner edge so the slider doesn't catch.
mechanism kit scotch-yoke retainer