This is a short video I shot demonstrating the arm extension mechanism on the Voight-Kampff.

The 2 pulley wheels and the coupling attaching the rods together I designed and 3D printed for this test, the thicker metal rod is a 7mm guide rod salvaged from an old scanner auicnd the thinner rod was taken from a pants hanger (it ran through the 2 clips on the hanger). For a quick and easy bushing for the rod to slide through I used HDPE (from kitchen cutting board).

Still picture of test: