In article ,
Lumpy wrote:
Lumpy wrote:
I want to add a small (4 or 6") cross table
vise to my drill press. I see similar tables

[ ... ]

DoN. Nichols wrote:
I do feel that I should ask what you are planning to do with
this. The reason for asking is that while these are fairly nice

[ ... ]

Not milling. Drilling .100 inch spaced holes
in printed circuit boards. No side load.

Great! This is an entirely appropriate application for the X/Y
table. Be sure to always feed in the same direction (and if you
overshoot, back up far enough so that you take out the slack when you
feed forward again).

Two drill presses. One a conventional Craftsman 1/2" chuck.
The other a dremel, 28k rpm through a 0.7mm dental burr.
Dremel is for the smaller stuff like component leads.
Craftsman is for the larger holes like mounting holes.
PC board material is generally laminated glass cloth,
1 oz copper clad.

I've drilled a lot of that. Ideally, you'll want solid carbide
drill bits for this. I once drilled about 80 holes in a small board
using a brand new #70 HSS drill bit (in a Cameron Precision sensitive
drill press), and by the time I was done, the drill bit was so worn that
it looked like a needle in shape -- and the holes were lined with
fibreglass fur. :-) Once I got some solid carbide bits, the problem went
away. (Be careful with them to not allow the workpiece to shift
sideways, however -- that will *certainly* break a carbide bit in an
instant.

What you might want for the small drilling is a sensitive drill
adaptor for the big drill press (so you can still use the X/Y table, and
yet can feed gently enough so you won't break drills.

O.K. No examples on eBay at the moment, so I'll try to describe
it:

1) 1/8" chuck (probably Albrecht, though I have seen them with
Jacobs chucks as well.

2) There is a 1/2" hollow shank to be gripped with the main drill
chuck, and a smaller shank sliding inside it -- with a key to
keep them rotating together. The smaller one has the small
chuck attached.

3) There is a spring to retract the small chuck back to the top.

4) There is a ball bearing assembly surrounding the smaller shank,
with a disc of aluminum press fitted to the OD of the ball
bearing assembly.

This allows you to use the drill disc to gently feed the drill
chuck (and whatever bit it is holding) into the workpiece,
instead of having to use the rather excessive leverage that the
drill press' feed arms offer. Thus, it is a lot easier to keep
from breaking the drill bit.


A sensitive drill press works well for the smaller drill bits
(I've used mine down to #80 bits), but usually has trouble reaching to
the center of a large PC board.

There are versions of the Cameron Precision which offer such
access, but mine does not. I think that it will reach to the center of
about a 4" -- maybe 5" board.

Enjoy,
DoN.
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