In article ,
Chris wrote:
Grant wrote:
um, "deflect". Do you mean it wanders and the hole doesn't start where
you think it should start? ...

English really is my first language, even if it doesn't show
sometimes.

The point of the bit makes 1 move, in one direction - it doesn't move
in a circle or make random motions. I could be convinced that it is
the chuck that is moving, rather than the bit flexing, too. I don't
see any sort of nut or screw or drawbar or ??? holding the chuck to
the machine, so I'm not sure how I would tighten it if this is indeed
the case.

I think your suggestion about the mill-drill is probably the right
solution.

It will help -- but what may help more is to get split point
drill bits. Normal drill bits have what is known as a "chisel point" --
a bar across the center which really does not cut, and which on any
irregular surface (or even on a smooth surface if you are coming in at
an angle) will sort of "walk" on the ends of the chisel point until the
bit deflects enough so the added force needed is sufficient to allow it
to start to bite in.

A split-point has a more complex tip geometry, which terminates
in a relatively sharp point which will not walk. That would help you
get these bits started where you want them.

Good Luck,
DoN.

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