For getting a drill centered on a section of a bolt that's a bit higher than
the surrounding metal, one could make up a set of drill bushings on a lathe,
that would center a pilot drill.
The bushings should get the drill started in the center, but won't help a
lot with axial pitch.
Not so simple when the bolt breaks off flush, though.

Managing a Dremel-type tool can be easier than trying to use a moderately
large drill motor to get a center start on a broken fastener.

Having a magnetic base drill for steel/iron base material would definitely
be helpful with keeping the drill on the axial center.
Mag base drills are generally large and expensive, but the recent shop-built
magnetic chucks made with high strength hard drive magnets shows that it may
be possible to make a smaller version for pilot drilling broken fasteners.

Another tool that would help get a drill centered and keep the drill on the
axial center would be a Cole drill. The foot/base that comes with the Cole
allows for easy attachment to an adjacent fastener hole (head surface on a
vehicle engine block, for example).
Again, this example isn't very compact, but an inspired HSM could make some
brackets to support a spindle and chuck, that would hold a drill
perpendicular to a surface.

I remember seeing a drill motor with bubble vials on it a number of years
ago, I don't remember the brand, or how long ago it was.

--
WB
..........
metalworking projects
www.kwagmire.com/metal_proj.html


"spaco" wrote in message
...
Thanks for all your input.
I learned several methods that I hadn't tried before.
One thing I could still use help with is actually getting the hole in the
exact center when drilling out a fastener. The @##$$$%^%^^^ bolt never
seems to be in a decent position to get straight at it. I center punch as
best I can, then drill undersize so I have room to correct, but I'm never
sure exactly where the center is until its pretty late in the game. I
sure wish that drill motors had X and Y levels on them!

I added your comments to the webpage that I put up yesterday or so,
http://www.spaco.org/MachineShop/StuckFasteners.html

Thanks again,
Pete Stanaitis
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