Filament Roller End caps for 22mm Tube

As soon as I saw HugoHuge's ingenious filament holder, I knew it was the one I wanted. But every time I printed the '3DPNFilHoldRoller' file I hit the same problem; the bearing pin snapped off. You can see one with exactly this issue in the main pic.

Sometimes it snapped off when I was printing it. Other times it was when I was trying to get the thing off the print bed. ...And once it went just as I was fitting it to the holder.

Now, it's almost certain that the problem's at my end. Either