A Joystick for the Twitch Block http://www.thingiverse.com/thing:1798009
Takes the place of the ball bearing at the end. The Gasket needs to be printed in some sort of flex filament. You can put a magnet in the end of it and one in the block if you want it to attract to the middle or how I like it oppose each other and act against you trying to center it.
I am also including a version of the block that prints in two parts - the whole stopping mid print thing was getting old when printing many of these.
Additionally is a version of the block which uses 4x2mm magnets to hold on the plates, Allows me to design new plates and swap them in and out easily.
Print anyway that works - I suggest high infill or a few perimeters as you want it strong