On Nov 20, 4:26*pm, Dave B wrote:
One our customers recently had an operator that left the chuck key in
the chuck and started the spindle.

They asked us to provide a solution and here is what it looks like.
We have installed 20 of them in the last few weeks.

Will not allow the spindle to start without the key in place and if
removed of course the spindle stops.

http://s32.photobucket.com/albums/d1...ion=view¤t=chu...

Dave B


For the truly paranoid worried about chips or a defeat cheat, you
could mount a spring loaded plunger on the top, where the plunger hit
the switch, and the switch would allow the plunger to 'overrun' a bit.

You'd have to insert the key into the top, push up a bit to gain
clearance for lip on the bottom, set the key into the recess on the
bottom.

This would keep chips from jamming the switch, and a defeat piece
would have to be purpose-built.
Too long, it won't go in, too short, it won't push the top plunger up
to trip the switch.

That's a lot more work, though!


Dave