When I built my yeethammer my plunger tube would torque down on whichever side it was being pulled from, and as a result the plunger wouldn't always latch. I found myself spreading my hand and grabbing the nut side of the bolt as well and it seemed to latched more successfully, but whichever side the bolt nut was on was unpleasant to grab. This is the result.
Uses the same hardware that comes with the yeethammer, and only requires an additional bolt nut holder printed for assembly. (The part in the red box in the last picture - takes less than a half hour total to print.)
Printed with 5 walls, 50% gyroid infill. Probably could be less, but I didnt want it to break.
The author remixed this model.
An alternate priming method that works with original hardware.