On 2010-05-14, Robert Swinney wrote:
Seems to me a drill press out of tram, even with a tilted table, would only tend to drill larger
holes - not holes at the angle of tilt.

Huh?

Perhaps if the workpiece was being rotated (such as in a lathe
chuck) instead of the bit.

However, if the bit is rotating (as is normal on a drill press)
I can't see how it would enlarge the hole (other than making it slightly
elliptical based on the angle, thus making a very slightly larger major
axis on the surface of the workpiece.) The diameter of the hole along
the axis of the bit will still be circular and as accurate as the bit
can drill anyway. :-)

But the *real* problem often with inexpensive drill presses is
that the force of the drill bit (especially with the usual chisel-point
bits) causes the arm supporting the table to deflect a bit, thus taking
a table which is in tram before you start drilling and forcing it out of
tram while drilling -- and then letting it return to tram when you
release the force. There just is not enough cast iron in the arm, and
not a long enough bearing surface on the column to prevent the
deflection. You can reduce it a bit by using a split-point drill bit,
which reduces the force needed to drive the bit into the workpiece.

Enjoy,
DoN.

--
Email: | Voice (all times): (703) 938-4564
(too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html
--- Black Holes are where God is dividing by zero ---