On Mon, 28 Dec 2009 01:17:42 -0600, Ignoramus27446 wrote:
On 2009-12-28, Bruce L Bergman wrote:
On Sun, 27 Dec 2009 00:39:14 -0600, Ignoramus9012 wrote:

My Powermatic 1200 has a reversing switch. It seems to work very
nicely for me.

http://igor.chudov.com/projects/Powe...-5845.jpg.html

That drum switch is NOT a proper "Big Red Panic Button" that you can
mash if things go very wrong, and we both know it. Install one, NOW.
Better yet install two, one high and one low. It doesn't have to be
beautiful, it just has to work.

Do you really want 100 of your best buds all yelling "I Told You
So!!" as you learn to type while short a digit or two for the rest of
your life? Or worse, the whole arm?

I definitely do not. OTOH, I have never seen a drill press with such a
button, either.

Then you haven't been looking very hard, Iggy. Or you simply choose
not to see...

The vast majority of the power switches on newer drill presses and
saws and such (unless they are imported from Elbonia) are right out in
front, and are a hybrid Push-Pull Toggle hinged at the top. Pull out
from the bottom to turn on, mash in to turn off.

The fancy ones on stationary tools have a Key Pin you have to insert
to turn it on, and if there are kids in the house you can take the
plastic key out and hide it. Keeps the under six set from losing an
arm.

The "keys" I've seen are easy to defeat with a sliver of wood and a
little whittling, but if the kid is old enough to defeat the lock he
should also be old enough to realize the tool can be dangerous.

Oh, and that drum switch better be connected as a signal-level input
to the VFD, and not be line voltage between the VFD and the motor.
Most VFD's do NOT like it when you open the motor leads under load,
the Magic Smoke tends to escape from the transistors.

Yes, 10v signal level input.

Good. And you used a hunk of CAT-5 cable (4-pair) between the VFD
and the switch, right? Should have taken two pair tops. So take a
spare pair and hook the NC contacts on a mushroom head Panic Button to
the E-Stop contacts on the VFD.

And the second remote switch down low or a few feet away can't hurt
- if there's a large piece of work spinning around on the chuck, you
might not get close enough to hit the button on the machine...

If I was running a CNC Shop where I wanted to start the machine and
let it do it's thing as I wander away to do something else, like
paperwork...

I'd have a video camera on each machine and a monitor on my desk -
with a remoted Little Yellow button for a regular machine stop (to go
out and replace a broken tool without losing the zero and the program)
and a Big Red Button for E-stop if you see (and/or hear) a full-on
crash happening.

Remember our r.c.m motto: Safety Third.

-- Bruce --