Bolt hole circle without a mill

[Bill_Hancoc]

dave beat me to it by 4 minutes


you should be able to scribe a circle on the part you want the holes on and then figure out where you want the holes...in this case ill use a 6 hole evely spaced bolt circle. First start by scribing the diameter you want the holes at. Find the degree of each hole 360degrees/6holes= 60degrees spacing. on the lathe mark a line then turn the chuck 60 degrees arny direction and mark you next 5 lines in this manner. to get the exact degree you need a backgear with 72 teeth which allows you to remove the pin and advance 1 tooth to rotate the chuck 5 degrees. to rotate the chuck an even 60 degrees rotate the chuck 12 teeth and replace the pin that will be every 60 degrees


hope this helps