Drilling tool

[msm19b034]

Drill bit linear velocity at center is zero. ( V = (R)(w) and R=0 at center).
Then how it is able to remove material at center? R-radius w-angular velocity

[seth.madore · Accepted solution]

Tip geometry and brute force, honestly 🙂

[matty.fuller · Accepted solution]

If you have an awareness of physics and want to get mathematical about it, you can assume that the drill is actually ground to a perfectly sharp point, then at the "point" which has zero velocity there is probably not actually any matter to remove, the atoms at the tip of the drill are somewhere near and adjacent to the nearest atoms of the workpiece.

Does this help you drill better holes?

[ed21b6]

In end mills, we do a "ramp and plunge"(RnP) operation to overcome this problem ( very low tool velocity at the center of the tool). This RnP ensures we are cutting with the outer edges of the tool where velocity is very high and not with the center of the tool, when plunging!. But this can't be done in a drill bit! So curious which aspect of the drill bit geometry enables it to remove material at center, even though the tool velocity is zero at center !!