Roger Korn wrote:
>
> At 06:16 PM 12/24/96 -0800, Bob Bachman wrote:
>
> >snip<...
>
> >I'm curious why you don't want a taper attached chuck. Actually, my
> >choice is a spindle with a #2 Morse internal taper. This allows you to
> >change chucks easily, use taper shank tools and taper collet tool
> >holders.
> >
> >Bob Bachman
> >
> >
> The problem with taper chucks is safety. I am primarily a woodworker and
> there are two situations that require some sort of positive attachment of
> chuck to quill:
> 1. Mortising attachments with a hollow, square chisel. The bit inside the
>chisel
> can jam up and cause the chuck to come off the quill on the upstroke.
>
> 2. The really dangerous one: using an unbalanced fly cutter (circle cutter).
>The
> asymetrical forces caused by cutting on one side of the circle are ideal for
> unseating the chuck from the quill taper. When this happens, you have about
> two pounds of chuck + flycutter zipping across the shop, hopefully missing
> your fingers, body, and other vulnerable objects.
>
> The ideal situation is many, if not most of the modern drill press chucks
> that can provide a screw-on collar that locks to matching threads on the
> quill, above the taper. This provides the ideal situation. Unfortunately, my
> 1936 Delta has no way of substituting a modern quill and chuck for the
> original, so I'm gonna have to ingratiate myself with my machinist buddy to
> get one made. It'll probably cost me an oak printer stand, but I've had
> accident #2, see above, occur twice and I'm losing my courage with advancing
> age.
>
> Roger, newly sober and counting my blessings along with my fingers
Roger,
I have seen a fairly effective fix to prevent the chuck from coming off
the taper by drilling a 1/4" hole up through the center of the chuck
body and then tapping a 1/4" X 20 hole up into the center of the
spindle.
Use a 1/4" flat head socket with some medium grip Loc-tite on the
threads as locking screw to keep the chuck in place. You may need to
alter the
screw head slightly and/or countersink the drill body. The normal
spindle rotation will tend to tighten the screw if the chuck slips on
the taper.
Bob
|