[TheForge] Drill press woes

[Andrew Vida]

On 7/2/2013 8:33 AM, Bob Ehrenberger wrote:
> Ron,
>
> You can probably get a Moris taper reamer and clean up the taper in the
> spindle.

	That will certainly do the trick, but it is a PITA.  As per the other 
branch of this thread, if you are sure the tapers are that worn, which 
would be a lot, you can lap them back into each other.

	What I would do first is get some Dykem HiSpot and give the make taper 
a light coating.  Then place the taper into the quill and gently rotate 
it in the socket back and forth in perhaps a 10* or 20* arc.  Then 
examine the tapered bore to see where you find red and where it is no 
longer red on the male end.  With that you can get an idea where the 
high spots are and perhaps how bad they are.  If they do not appear to 
be too terrible, then goo up the taper with lapping compound, jam it in 
the hole gently and very gingerly lap the parts back into each other. 
Try not to push too hard because the taper may seize in the hole and 
with the grit holding it fast you may have a more difficult time getting 
it back out, especially if you do not have the proper drift.

Even a relatively coarse compound will do as the crystals will break 
down fairly rapidly.  After a while they will become so fine as to 
polish the surfaces, though that much work should not be necessary.

You can actually run the drill and hold the taper by hand, applying 
gentle pressure.  Make sure the chuck is closed tightly an be VERY 
careful because if the taper catches, the chuck will not remain still 
and if you are gripping too hard you could end up with an unpleasant 
surprise.  Always remember: machine is strong and dumber than a post.

Also, do not limp-wrist the taper.  Too little pressure can cause the 
geometry of the tapers not only to change, but to diverge rather than 
converge.  Run the press SLOWLY - slowest speed it has.  If it cannot go 
below, say, 300 rpm, do it by hand without power.  Every once in a while 
increase pressure to see whether the taper grabs.  When it does, you 
will know you are very close to finished, or even there.