Re: Sensitive Chuck for Drilling


Jim Betz
 

Hi,

A friend of mine built a sort of roll-your-own drill for this
purpose. It is little more than a 1.5 inch diameter 12vdc
motor that has a chuck on it that will hold drills down
to a #80. He powers it off of an old DC power pack and
uses that to control the speed - and holds it in his hand.

The advantage to this is that it is hand held and so the
work goes a -lot- quicker than using any kind of drill
press. Even with a precision table you still spend a lot
of time moving from one hole to the next ... and also
figuring out how to hold the model on the table.

He does the same thing I do which is to never use
the recommended drill size. If a #80 is the 'correct'
size use a #78 or even a #76. You will not notice that
the holes are a bit too large ... and the ease of getting
the wires into them is not just meaningful it is great.
And you break a lot less drill bits. *G*

If you use a very fine point such as those found on
the old compasses or better yet "dividers" (a tool I
would not know how to work on models without)
you can 'pre-punch' the holes. This helps a lot to
position/guide the drill when making the actual
holes. The dividers I have are at least 50 years old
and were an essential tool for anyone doing any
sort of "navigation" using nautical charts.

I have seen some 'micro chucks' on eBay but haven't
bought one yet. The key 'accuracy' issue with small
drills is that the chuck has to be designed to hold them.
I have tried holding a pin vise in a drill press and it
is hard to get it lined up so that the tip and drill are
turning true. And there are the issues related to how
much slower it is to do the actual holes than any
kind of hand held method. If I'm only doing the
holes in a single model I almost always end up just
hand holding the pin vise ... *G*.

Although holes that are perfectly perpendicular to
the surface of the model are better/preferred ... I
always seem to be able to hold a pin vise close
enough to perpendicular that it isn't any problem.

- Jim Betz

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