Jansen 123.8 mm Lower Link
Lower link k for the 'NEMA17 Twin-Motor Strandbeest Walker' kit (print ×4). It joins crank pin M to foot vertex K. The two 4.5 mm M4 pivot bores are exactly 123.8 mm apart, centre to centre, and each sits in a 16 mm OD × 6 mm hub. The flat-bottomed 14 × 5.5 mm bar is 139.8 mm long overall, with a 1 × 6 mm lightening groove along the top and a 3 mm hole at mid-length that marks it as the long link. It runs on an M4x35 (M, K') or M4x30 (K) socket head pin, with washers and a nylock nut.
mechanism kit strandbeest jansen-linkage