This paddle was given to me by a friend of mine who wanted me to try out his design. This prototype unit lacked the "presentation finish" that many of us like on our paddles, but the design was so solid I felt it was more than worthy of a makeover to give it an appearance that matched its functional quality. For years now this paddle has been my "daily driver".
Except for the base, most of the parts on this paddle are aluminum. For weight, the base is steel (not stainless unfortunately) that I sprayed with a clear coat to keep it from rusting. The paddle levers pivot on shafts supported at both ends by sealed ball bearings which are glued into the central bearing block. Small setcrews and some glue hold the levers on the shafts. The levers themselves are made from slices of large extruded aluminum angle. The contacts are silver buttons scrounged from relays and are soldered to the stationary adjustment screws. Since the contacts couldn't be soldered to the aluminum levers, they were left attached to small pieces of their original relay armatures which were then screwed into the levers.
Tension is provided by ballpoint pen springs which are coaxial with the tension adjustment screws. The springs also give an additional current return path to ground for the moving contacts in addition to the path through the ball bearings. All adjustment screws are held in place with jam nuts. This method is simple to construct, but adjustments can be a tedious trial and error procedure because the 4-40 threads are fairly coarse and the screw gets loose and wobbly as soon as the jam nut is loosened. Short of going to a fine precision thread, a way around this might be to use split posts with a pinch screw like Bencher does on their paddles.
The white caps on the return stop screws are Teflon bumpers to quiet the return click. I haven't noticed a contact spacing drift problem due to these deforming over time, but you could argue that Teflon might not be the right material to use here. Since I made the initial adjustments, everything on this paddle has stayed put for years, so I haven't felt the need to make any changes to the design.