Can anyone give me advice on removing a Jacob's chuck from a Rockwell
drill press? I think it is a Jacob's taper. The drill press is model
15-069, but I imagine that doesn't matter much.
Someone left this drill press in a humid place, and the chuck got frozen
from rust. Had to damage it to open it up.
To rule out the obvious, is there an oval shaped slot cut into the quill
that you can insert a drift key (ie. rectangular piece of metal with a taper
on one side)?. If not, have you tried using a tie rod separator (ie. a
tapered fork intended for car repair that you insert between the chuck and
the drill body)?
I have one of these sets (they make different ones for different tapers). I
never figured out how to use it. There is too much space between the top of
the chuck and the bottom-most surface on the drill press. Am I supposed to
make a spacer?
[ ... ]
It is presumed that there is a shoulder on the spindle just
above the chuck. It is important that the wedges match the size of the
taper (you should be able to find a marking on the side of the chuck
saying something like "J33" (Jacobs 33 taper) or similar. If the wedges
are too big, they will just slip past the shoulder.
And there are some cases of arbors which have no visible
shoulder (usually when a smaller Morse taper is going into the quill,
and a larger Jacobs taper into the chuck.) An example would be a JT-6
or a JT-33 with a MT-2 arbor.
Note that while some suggested that you look for a slot for a
drill drift to extract an arbor, what they did not tell you is that it
may not always be visible. *Sometimes*, it is -- on an extension
below the quill. But -- *sometimes* it is not.
On my drill press (a floor-standing Taiwanese model from about
1978 or so) it is not visible until you use the feed levers to advance
the quill a few inches. Look on the side of the quill, and you may find
a pair of slots opposite each other by 180 degrees. If you find that,
you should find a second pair of slots in the internal rotating part.
You may have to rotate the spindle by hand to make those line up with
the external ones.
To remove my arbor (MT-2) from a larger chuck (JT-6 or JT-33), I
would have to drill a hole through the arbor for a cross-pin, and add a
spacer between the cross-pin and the chuck body to support the chuck
There are other ways as well -- with a chuck which has an arbor
instead of being mounted directly to the spindle. One is to mount a
drill bit in a drill press vise ponting upwards, and bring the fully
opened chuck down over the bit to drill a centered hole through the
chuck into the cavity which is the Jacobs taper. Then remove the arbor
from the drill press spindle, move it over a big heavy vise, support the
chuck with the vise jaws, and use a punch through the just-drilled hole
to drive the arbor out.
But if you have an arbor which can be removed from the spindle,
and are changing the chuck, you may need a different arbor to adapt to a
different chuck taper anyway, in which case the separation of the chuck
from the arbor is just an exercise to prove that you can do it -- or
perhaps to save the arbor for some other later use. :-)
On Mon, 04 Oct 2004 03:02:05 GMT, "AL" calmly ranted:
Only if you want them to work. ;) Improvise, man! That's the heart
and fun of being mechanically inclined. We get to make "stuff". If
a tool doesn't work, we think up a new one for this problem and new
uses for the tool. When one solution doesn't work, we think up a new
one. We keep the ideas flowing until the solution is at hand.
Just Do It! Put into reality that which Goldberg could only pen!
I suspect a J33. I would try a pipe wrench on the chuck, set the
handle where it can smack the column (protect with a board if you
want) and flip the power switch quickly. May need to bump it a
few times, but should pop it loose with the least beating and
Keep the whole world singing . . . .
DanG (remove the sevens)