This is a remix of dist's excellent PÄR² joystick, but split to make it easier to print the rounded corners. Additionally, I changed the cord hole to a DB9 connector, to make it easier to just use a DB9 serial cable to use as the joystick's cord.
I used the following hardware to build the stick:
M3 x 12 flat head machine screws (to replace the ones that came with the joystick)
#4-40 machine screws and nuts (to retain the DB9 connector)
DB9 female solder-type connector