if you have a 2 inch diameter piece for instance, set a pair of dial
calipers[preferably the 15 dollar chineses ones] a tad over half, say
1.015. scribe a number of lines near the center of the shaft from
different points on the circumference. Of course layout die[read
sharpie] makes it easier to see. You will end up with a pattern grouped
around the center, making it much easier to see if you are in error when
you center punch it. I prefer solid punches to the automatic ones,
sharpened to a nice sharp point.
Tap very lightly the first time, so if it is visibly out of center, you
can fix it.
drill with a small center drill or a 1/8 inch drill. drill progressively
larger

Much of this relates to your eye; if you can see[and care about] the
error or not. If your scribe marks are ~.03 apart, the average person
can 'see' ~.005 error, if they want to.

Silvan wrote:
Doc wrote:


Looking for any tips/tricks for drilling a hole w/a drill press that's as
close to dead-center to a specified point as possible.


First tip: use an awl or center punch (depending on whether it's wood or
metal you're drilling) to mark the precise location of the hole first.
Even with a brad point bit, it's difficult to prevent drills from wandering
off the target when they enter the material. The smaller the gauge of the
bit, the worse the problem is.

Second tip: depending on the nature of the work involved, you may be able
to use a cross-slide vise for fine positioning of the work relative to the
bit. They only work on stock that can fit inside the jaws, but they are
quite useful to have when precision matters.

Something like this:

http://www.grizzly.com/products/item...emnumber=G1064

Now, whether you have one of those handy gizmos or not, position the work
(with the hole locations pre-punched), then pull down the quill with the
motor off. Listen for a plinking sound, and watch with hawk eyes for the
slightest bit deflection. If the bit is deflecting to enter the dimple,
your hole won't come out right.

I find it helpful to rotate the chuck by hand to position the flutes or
other cutting edges in a way that allows a clear view of the very tip of
the point in relation to the dimple. Repeat the process of making fine
adjustments to the X and Y axes and then checking with the quill until the
bit enters straight and true, then drill the hole.

This process is tedious and time consuming, but if there's a better way to
ensure a hole as close to perfectly placed as possible with a drill press,
I haven't discovered it.