GM0EUL Keys and printed gizmos
I set out to develop a miniature paddle that was at least as good as my beloved Palm Pico Paddle, sadly Palm Radio closed down and these are no longer available but will forever remain the iconic paddle for the ultra-lightweight portable operator.
So the bar is very high and with this first release version of the UMPP (Ultra-Miniature Precision Paddle) I believe I have achieved it.
Best in class principles
I looked at the attributes of some of the acknowledged best keys in the world including my own Begali Expedition (S/N 499) . Begali and other top end manufacturers use precision bearings to support the arms and magnets instead of springs for a deliciously smooth action. So does the UMPP-1
And not all miniature bearings are the same. To enable precision adjustment of the gap, a consistent action and minimal variation between units and batches you need tight tolerances. I use Japanese EZO bearings which are smooth running, noise and vibration tested and Abec rating 3-5/tolerance P6-P5. Cheap bearings bought online can be far too wobbly (Abec 1/Tolerance P0) for precision equipment.
Each one built with love
I want you to love your UMPP-1 and I put a lot of care into building each one by hand.
The main components are 3-D printed from PFA, a plant based plastic-like material that is much less harmful to the environment than conventional plastics.
The printed components are finished by hand to give them a smooth and tactile feel. The bearings and magnets are held in place with epoxy resin and the contact points are adjustable by means of stainless steel grub screws. Pure copper foil is used for the contacts and the key is wired for a standard 3.5 mm jack plug.