The other day Richard and Melinda showed up at one of our EDH workshops. She had problems with her gas filler for Vinzenz, which leaked badly. So we decided to make a new one which lets her use the Asian butane cans. It turned out to be a very simple and effective gadget. It is made from 1/2" Delrin. The hole which slides on the can valve was reamed 4mm, but a 5/32" drill may do the job. The hole on the other side can be opened out with a 1/16" drill and the cone is done with a center drill (opened out to slighly less than 1/8"). It took longer to make the photo and describe how to make it than "manufacturing" it.