Re: Cutter Radius Compensation

[Ray Henry <rehenry-at-up.net>]

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