Roger Korn writes:
>
> At 06:16 PM 12/24/96 -0800, Bob Bachman wrote:
[why not tapered chucks on drill presses?]
> 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
I've heard of people mounting a drill bit in a vice on the table, and
lowering the chuck with its jaws open onto it, drilling a hole through
the chuck and into the tapered shaft. Remove the chuck, tap
the shaft (or maybe you can simnply tap the chuck and
the shaft together) and then thread a good quality machine screw
into the tapped hole. This is supposed to keep the chuck from loosening.
You'd probably want to make sure the chuck was tight on the shaft
before doing this, and you'd probably want to use thread-locking
compound on the screw.
I don't remamber where I saw this, and I haven't tried it myself, so
I can't recommend it. But maybe someone else here knows more.
It sure seems like it'd work well.
--
Eric Murray Chief Security Scientist N*Able Technologies www.nabletech.com
(email: ericm at lne.com or nabletech.com) PGP keyid:E03F65E5
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