In the book Machine shop trade secrets - there is a print for a 3" diameter 1.5 inch thick with 7/8 arbor and through the center goes your cutter - I built one and used it for the following
[video=youtube;zo04S2mjkTA]http://www.youtube.com/watch?list=UUe4eLPphlnH7HGn_smXtk8A&v=zo04S2mjkTA& feature=player_detailpage[/video]
that was a special bar I made just for that project but I have different bars and it is super ridged
and my mill is R8 spindle if I am fly cutting I do slow rpms in back gear and about 15K to 25K depending on what I am cutting
and it makes a great trepanning tool
[video=youtube;zo04S2mjkTA]http://www.youtube.com/watch?list=UUe4eLPphlnH7HGn_smXtk8A&v=zo04S2mjkTA& feature=player_detailpage[/video]
that was a special bar I made just for that project but I have different bars and it is super ridged
and my mill is R8 spindle if I am fly cutting I do slow rpms in back gear and about 15K to 25K depending on what I am cutting
and it makes a great trepanning tool