Jam Chuck with Shop Made Faceplate

This is a jam chuck. It is used to hold a bowl or a platter when you want to reverse it and work on The bottom. Normally you would make a jam chuck by using an MDF disk and cutting a groove that would properly hold the rim of the bowl. The variation that you are looking at, uses 4 scrap boards glued onto of the MDF disk. Then a groove is cut into the boards to hold the bowl you are reversing. After you have used the jam chuck and cut several different grooves into the boards, you can simply turn off the remaining part of the boards and glue 4 more boards onto the MDF disks. This is easier than starting with a new disk, or gluing a new disk on the on top of the old disk.