Toothpaste Roller that just works

Yes, another toothpaste roller. This unit was designed using specifications from an old Marquette EKG electrode gel tube roller. It simply works. I created two outer shells. The original unit is round, but I thought a hexagonal shape might be nice, so I added that feature.

The shell should print without support.
You might want to add support on the shaft, but I didn't, and it printed fine.
I also suggest upping the wall loops to 4 or 6 to add strength to the print. That depends on how aggressively you might try to get the last out of the tube.