Hi Guys,
Lack of balance and vibration are just two of the issues with fly cutters.
These are my fly cutter tools !

This one is on a 20 mm shaft and is made from a 20 mm thick steel disc three inches in diameter.
The tool bit is basically any old bit of broken HSS. The piece that you see in the disc is a bit of 6 mm HSS, square lathe tool ground as required. It is simply secured by a single hex grub screw.

This picture shows using a fly cutter to machine the fork of a bearing holder to a given thickness. The tool was simply turned over to cut the other leg and the mill run the other way.
The large body mass has a flywheel effect and reduces vibration due to any out of balance.
Edited By John Baron on 20/09/2018 15:01:15