When you pak two part....left and right part.....there is some 柱 in order to hold two parts....let think about DW...one side with hole is ww....and the other one is jj OKAY.......I always use the cutter made more wide of the hole, so it will easy to "pak", also can easy for separate two parts when you want to spray color.......The main purpose is make it loss...not to tight:handshake: