Re: [CAD_CAM_EDM_DRO] Cutter compensation

First of all, you should know that cutter comp is usually
implemented in the first linear X-Y move after it's
callout. Generally, you must feed a distance of at least
the cutter comp distance to effect it. This means that
before you get to the starting point, you must place the
tool in a 'lead-in' position, so that when the cutter comp
takes effect, the tool will be where you want it. If, for
example, you want left C-C, you'll call for G41. The
sequence of co-ordinates you show will yield a
counter-clockwise path INSIDE the 5x5 square, using a
process commonly referred to as 'climb milling'. Also, it's
best not to start a cut in a corner (actually, forbidden in
some software). Better to start somewhere in the middle of
the linear cut, so for your part: (assuming dim's are
inches, and E.M. is in mm)

G0 X0 Y0 Z0 ' rapid move to 'Home' position
Tn M06 'change to tool #n
M03 Sxxx 'set cw spindle at xxx rpm's
G0 X2 Y.5 Z.1 'rapid move to those coordinates
G0 Z-.xxx 'rapid down to cutting plane
G41 Tn 'initiate the cutter comp (& length
offset, if req'd) stored for Tn
G01 X2.5 Y0 Fxx 'lead-in to our starting point at Feed of
xx units/min
X5 'feed to lower right-hand corner of
square
Y5 'feed to upper right-hand corner of
square
X0 'feed to upper left-hand corner of
square
Y0 'feed to lower left-hand corner of
square
X2.5 'feed to starting point
G40 X3 Y.5 'feed through the lead-out, cancelling
cutter comp, on the way
G0 Z.1 'get back above work plane
X0 Y0 Z0 'go home
M2 'end program

The CAM program must 'look-ahead' to see where the next cut
will take the tool, and compensate accordingly. Some
software asks for an angle (P) to indicate the direction of
the next cut to implement that function.

So, the path of the tool C/L will be (X0,Y0):(X2,Y.5):
(X2.5,Y.1181):(X4.8819,Y.1181):(X4.8819,Y4.8819):
(X.1181,Y4.8819):(X.1181,Y.1181):(X2.5,Y.1181):
(X3,Y.5):(X0,Y0)

The resulting pocket is 5" x 5" inside, with .1181R inside
corners. HTH

RayHex
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> From: sid8ball <sid8ball@...>
>
> When I select cutter compensation to the left or the

right what is

> the equation the cnc control computes. And when it rounds

accute line

> angles with a rad what angles does this work on. For

example

>
> G00 x0 Y0
> G01 x5 y0
> G01 x5 y5
> G01 x0 y0
>
> For the above program if I wanted tool comp to the left

using a 6mm

> dia tool what would be the new points if i were to

program using no

> tool comp.
>
> Any help would be most appriated.
>
> cheers
>
> Sid