I've broken the bottom (threaded) cap for my "Good Luck" 12 meters long fishing pole and lost the top (rubber) one, therefore had to design my own.
I've printed mine in PETG, PLA should work just fine. Use lot of perimeters, top/bottom layers and infill for extra strength - may help during a collapse.
Good Luck is not a reputable fishing rod manufacturer, so your dimensions may differ. If too tight or too loose, just scale the parts by few percent.
To find the original Onshape designs, search for "goodluck_top_cap" and "goodluck_bottom_cap" in Public designs.
good_luck_bottom_cap.stl | 2.7MB | |
good_luck_top_cap.stl | 2.2MB |