Depends on how bad it is, but a little technique may help get the best out of what you have.

First make an accurate centre-pop on the workpiece.

Then clamp the job tight in a machine vice, but don't bolt the vice down hard on the table. Leave just enough slack to allow it to shift sideways. (But firm enough to control a grab – my pillar drill is the most dangerous tool I own.)

Set the drill up so the tip of the drill is close to the work and aligned accurately with the centre-pop. (I use a dress pin with a big round plastic head stuck to the drill tip with plasticine as a wobbler).

Now the counter-intuitive bit. Might be expected holes will be more accurate if the workpiece is clamped firmly down. Don't. Instead, with the drill spinning at the speed suitable for it's diameter, feed the drill into the centre-pop and allow the work to align itself with the drill. You can see if the drill is being pulled off course as it engages – correct as necessary. Then go for it.

This works because a spinning drill prefers to stabilise on its axis, and the axis needn't be forced by tight accurate bearings. Provided the work is aligned with the spinning axis and the drill allowed to cut, it can be accurate. Think gyroscope. The secret is to let the workpiece go floppy and float into alignment. Takes a little practice.

Accurate drilling in a milling machine is easier. Mills are far more rigid than most pillar drills unless the bearings are trashed. Bolting down hard for accuracy works well on mills. And as a slightly inaccurate centre-pop makes things worse on a mill by pulling the drill off-axis, I don't bother with them. Instead, I start with a centre-drill or just go straight in with an ordinary one.

Dave

Edited By SillyOldDuffer on 03/08/2020 18:05:25

What size do you need to drill ?

"Larger diameter" is a bit vague, like, "How long is a piece of string"

I have a 16 speed Taiwan 16 speed drill with a 5/8" chuck, which with the chuck removed, can handle 1" drills with no problem. After that I use the milling machine.

Horses for courses.

Brilliant, I shall remember that one!

Dave