Determine How Many Flutes To Use
How do I determine the number of flutes for a turning?
There are basically two ways.
One is the mathematical one. Measure the diameter of the turning and multiply by 3.1415 (π x diameter) to get the circumference. Add the width of the fluting bit to the width you want between flutes and divide the circumference with that figure.
For example, if the circumference is 16 inches, using a ¼ inch wide bit and ¼ inch between flutes, then divide 16 by ½ to arrive at 32 flutes. You must be careful that flutes don’t run together at the smallest diameter of your turning. So in this case 28 flutes might be used.
The second method is the one I prefer. There are two places on the index wheel where four holes line up from outside edge to the center. With the pin in one of those four holes, make a shallow flute cut on a small diameter part of your turning. Then see how many holes you want to move for the next flute. That way it is visual and you will get what you want. Check with the included index chart to see how many flutes will be produced using the row of holes on the index wheel.
I think flutes looks best when placed fairly close together, but this is a design decision.
Posted on Mon, June 5, 2017
by Dick Webber