Re: Cutter Radius Compensation

["Frank Hess" <hess-at-flatplate.com>]

Thanks Ray.  I _have_ read the section of "The NIST RS274/VGER
Interpreter" that deals with this topic but I must be too dense to
understand it.

Later,
Frank

----- Original Message -----
From: Ray Henry <rehenry-at-up.net>
To: Multiple recipients of list <emc-at-nist.gov>
Sent: Tuesday, December 14, 1999 15:50
Subject: Re: Cutter Radius Compensation


>
> Frank
>
> I hadn't gotten quite that far studying RS274NGC.  I'm still working on
> outside comp but here goes what I found.
>
> I got your code to run if I turn on diameter comp and approach the first
> end of the first arc from outside of the circle.  You'll need to get the
> cutter right close to the surface before you turn on comp.  Moving z after
> comp messed it up for me.
>
> This is what I ran:
>
> N0010 G53 G0 Z0
> N0020 X-1 Y1 (load position)
> N0030 G43 H2 (activate tool length comp)
> N0040 G1 X1 Y-1 F25 S1000 M4
> N0045 z0.01 (z axis just above surface)
> N0050 g17 g41 d2 X1 Y0 F25 (near start corner)
> N0080 G3 X-1 R1 Z-.05 F3
> N0090 X1 R1 Z-.1 F3
> N0100 X-1 R1 Z-.15 F3
> N0110 X1 R1 Z-.2 F3
> N0120 X-1 R1 Z-.25 F3
> N0130 X1 R1 Z-.3 F3
> N0140 X-1 R1 Z-.35 F3
> N0150 X1 R1 F3
> N0160 X-1 R1 F3
> N0170 X1 R1 F3
> N0200 G40
> N0210 G0 Z3
> (Frank Hess)
>
> This way the interpreter treats the x1 y0 as a hard corner and does a
> little arc dance around from the end of the comp approach to the face of
> the arc itself.  The first helical z ramp will be a little steeper that
the
> way you planned.
>
> (wish I could draw here)
>
> Good luck.
>
> Ray
>
> -----om-----
> At 08:47 AM 12/14/1999 -0500, Frank Hess wrote:
>
> I am having a problem trying to use cutter radius compensation with
> circular interpolation.
>
> We have a Bridgeport milling machine running the emc controller.
>
> I want to use a 1/2" end mill to "part" a slug from a plate and produce a
> 2" dia. hole.
>
> I have included a portion of the code below.  Can anyone tell me what I am
> doing wrong?
>
> I am pretty sure that the problem is in the approach moves.  Depending on
> how I approach it I get different error messages when it reads the G3
block.
>
> Assume that tool 2 is loaded in the spindle and that a .5" dia is loaded
in
> the tool table. Center of hole is at X0Y0.
>
> N0010 G53 G0 Z0
> N0020 X-1 Y1 (load position)
> N0030 G43 H2 (activate tool length comp)
> N0040 G1 G41 X0 Y0 F25 S1000 M4 D2
> N0050 G1 X1 Y0 F25
> N0070 G1 Z0 F5 (position Z axis)
> N0080 G3 X-1 R1 Z-.05 F3
> N0090 X1 R1 Z-.1 F3
> N0100 X-1 R1 Z-.15 F3
> N0110 X1 R1 Z-.2 F3
> N0120 X-1 R1 Z-.25 F3
> N0130 X1 R1 Z-.3 F3
> N0140 X-1 R1 Z-.35 F3
> N0150 X1 R1 F3
> N0160 X-1 R1 F3
> N0170 X1 R1 F3
> N0200 G40
> N0210 G0 Z3
>
>
>
>
>
>