Poul Ladegaard's Air Bearing Tangential Tonearm!
The picture shows the final version of the author's (Poul Ladegaard) first prototype. Here he uses a sort of ball bearing to pivot the arm. Later he found that knife blades work equally well. (Stanley blades seem fine)
The arm tube is a carbon fibre tube, actually from a badminton racket. This seems to be a very good choice of material for the arm. The mid graph of 'armgraphs.jpg' shows measurements of vibration done on the arm using a high level sweep. The arm behaves well, as the graph shows.
The arm lift appearing on this picture is made from bent piano wire and an oil damped lift from an old Colton arm.