Machine drills sqaure hole

[jetboat]

i see it but i dont believe it.

It just looks different to us round-eyes.

[turbostang]

The noise you hear is the eccentric inside of the mechanism, that is in turn inside of the chuck. Depending on the size/shape of the cutter determines what it can cut.

For example, I used to run an engine lathe that was primarily used for cutting hex shaped holes (that were used for a really BIG allen wrench). This cutter only had 5 sides, but the eccentric it went insde of made it cut a 6 sided hole. Really wierd... made a very similar noise. Perfectly safe.