(Another) bicycle headset pressing tool. This time for 1 1/8", 30.2 x 41 x 6.5 mm angular contact ball bearings. Should also work (what I'm going to use it for first) to seal off the seatings while spraying the frame.
Uses a 12 mm screw down the middle - yes, in my case, that has to be that short, but longer screws/bolts/threaded rods do exist. In addition, requires a nut (of course) and two large washers (google translates "Karosseriescheibe" as "body disc", so be it).

Print it pretty solid, I used 4 walls and 30% infill.