On Fri, 19 Mar 2004 07:18:16 -0500, Peter T. Keillor III
wrote:

On Fri, 19 Mar 2004 05:04:59 GMT, Gunner
wrote:

On Thu, 18 Mar 2004 20:08:07 -0600, "Bob Swinney"
wrote:

Peter sez: " Just curious, what do you use instantaneous, as opposed to
fast,
reversing for in machining (I'm still a newbie)? Also, is there any
electrical downside to really fast reversing on either a converter or
vfd? I have a L-00 spindle, so I'm not overly concerned with sending
the chuck across the floor."

Mine was intended to be a commentary on reversing, in general, not an
indicator of any particular preference. Personally, I have no need for
reversing other than that which occurs when the machine coasts down to a
gentle stop. I am told some use "fast reversing" for power tapping on a
vertical mill. IMO, power tapping is yet another incursion of technology
into one of the last realms of craftsmanship.

Bob Swinney

I use fast reversing for tapping on my Gorton Mastermil, which has a
HEAVY spindle, and on the various lathes here in my hope shop.

Most production shops use fast reversing for CNC lathe tapping, wobble
broaching, and for cut off (gang tooled machines with the cut off tool
on the back side.

Gunner

snip big sig

Thanks, Gunner. So it's a primarily a production technique.

Pete

Yup..but..when tapping, and you will G tap on the mill sooner or
later..its right handy.

Im making a couple sets of QC tool holder posts and blocks for myself
and a friend. Im nearly done, and each holder has (24) 1/4-20 clamp
screw holes. I just finished 8 of them G

One drill bit, one tap, fast reverse. Worked like a champ and I was
only a couple hours doing it all. Doing that by hand...and Id still
be at it G

The center column of the tool holder..the part that attaches to the
lathe cross slide, were all drilled and tapped on the lathe as well,
using quick reverse. Floating tap holder in the tailstock.

The VFD really pays for itself on jobs like this.

Gunner

"As physicists now know, there is some nonzero probability that any object will,
through quantum effects, tunnel from the workbench in your shop to Floyds Knobs,
Indiana (unless your shop is already in Indiana, in which case the object will
tunnel to Trotters, North Dakota).
The smaller mass of the object, the higher the probability.
Therefore, disassembled parts, particularly small ones,
of machines disappear much faster than assembled machines."
Greg Dermer: rec.crafts.metalworking