RE: [CAD_CAM_EDM_DRO] emc g92

Hi all,

I've had a P133 running Linux with EMC on it for a number of
years now (sitting in a corner gathering dust actually).

The intention was to add it to my Drill/Mill XY vise with some
size 23 steppers. Never did get around to it with the Gingery
Lathe project and other things always taking precedence.

But this thread has been very interesting. I read through the
EMC manual last night, including the parts by Jon Elson looking
for clues about the G92 instruction. Either the manual is very
old or there just isn't much.

So that brings up an interesting question alluded to by some of
the posters. I can see installing each milling cutter in a
removable insert pulled automatically off a tool tray. I can
see setting up the insert so the machine knows where the end of
the tool is. Then each time the tool is grabbed it uses the
correct offset and all works well.

But for the home/light_industry CNC world where a program might
use three different cutters, how is this set up if the G92
command doesn't work? Is there a different command?

Say I had three end mills which I wanted to use for three
different slots. (Yes, I know, use the smallest and make
multiple passes). What would a program for the EMC application
look like to cut three slots, 1" apart for two inches, X=3.000,
Y=3.000 away from the home position. Let's make each of the
slots 0.100" deep so they can all be cut in one pass. Oh yes,
to make things a bit more difficult, two of the cutters have the
same shank diameter and one is a bit smaller.

My Drill/Mill has MT-3 tooling so I'd have to move the table out
of the way, undo the drawbar, whack the drawbar with a mallet,
unscrew the MT-3 the rest of the way and insert and tighten up
the other MT-3 holder. Or would I keep 3 MT-3 holders in stock,
each with their respective cutter and measure the end of the
cutter relative to some 0 point for each cutter? Base of the
Spindle perhaps?

People have discussed moving the cutter down until it touches
paper that is 0.005" thick so there I'm assuming that the cutter
is changed in the holder and sits at a different height and then
adjusting for the 0.005".

So what would the program look like? Seems it would be a simple
G-Code application so could someone experienced post how they'd
do this? How would it be done in Turbo-CNC. How about some
commercial machine?

Thanks

John Dammeyer


Wireless CAN with the CANRF module now available.
http://www.autoartisans.com/products
Automation Artisans Inc.
Ph. 1 250 544 4950