On 2008-04-09 16:34:10 +0100, Adrian C said:

geraldthehamster wrote:
I need to drill accurately some holes for taps in a 40mm thick beech
worktop.

How might I ensure that I am drilling exactly vertically, with my hand-
held drill?

Forget the drill. Mark exactly where you need the holes. Stand the
worktop flat against a house wall and stand a measured and calculated
distance back. Take account of any local interference such as wind in
your calculations.

With your shooting rifle ready, do the necessary.

Important. Make sure no one is in the vicinity inside the house or out.
Some bloke did it while installing his satellite dish, things did'nt go
down too well.

Certainly his wife didn't after that.....