Expert: J. B. Borge - 4/25/2005

Question
I would like to know how to draw a helix on a typical drill bit. This will be my first time attempting this. Thank you.

Answer
Colin, there are several ways this can be done in autocad. You have to have a bit of understanding in surface or solid modeling using bolean operators. This procedure gets really indepth & too long to even write down but this is typically the generic process: Extrude a circle, rendering the OD (cylinder) of the drill bit. using the same plane used in the circle, create an ellipse (with its quadrants running thru the circle's profile) & project a helical extrusion using the cylinder's axis as your center of path. recreate the same procedure but exactly the opposite of the initial extruded ellipse. Now use bolean subtract to extract the 2 helix leaving you the core of the bit. So in essence, you're creating a cylinder, extruding 2 helical ellipses, then subtracting. Hope you get the concept.