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G code issues
« on: February 27, 2014, 12:23:48 PM »
Hello All.

I am trying to invoke a G41 radius compensation in conjunction with a G3 circular interpolation. The coordinates should cut a circle but instead I am getting a scroll.
If I turn off the G41 the circle cuts correctly but is oversize. I am trying to avoid center of tool programing for the particular program.
 
What a I doing wrong?

Offline ger21

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Re: G code issues
« Reply #1 on: February 27, 2014, 03:06:22 PM »
Show us the code, but it sounds like you don't have a proper lead in move, which might cause the compensation to be variably applied along the circle.
Gerry

2010 Screenset
http://www.thecncwoodworker.com/2010.html

JointCAM Dovetail and Box Joint software
http://www.g-forcecnc.com/jointcam.html
Re: G code issues
« Reply #2 on: February 27, 2014, 06:40:14 PM »
O0046

( PROGRAM TO CUT CIRCLE AND BOLT HOLE PATTERN)
( FEB 24 2014)
(G54 X0 Y0 Z0 IS CENTER OF CIRCLE)

G17 G20  G40 G54 G80 G90
T01 M6
G90
G0 X5.75 Y6.875
M3 S500
G43 H1 Z.5
G1 Z-.7 F20
G41 D1
G1 X3.25
G3 X3.25 Y6.875 I2.50 J0
G1 X3.125
G3 X3.125 Y6.875 I2.624 J0
G3 X5.75 Y4.251 R2.624
G0 Z1.0
G1 G40 X0 Y0
M5
T02 M6
G91 G28 Z0
G90
G0 X9.1752 Y6.875
M3 S500
G43 H2 Z.5
G83 Z-.7 R.05 Q.5 F40
X8.172 Y9.297
X5.70 Y10.30
X3.328 Y9.297
X2.3248 Y6.875
X3.328 Y4.453
X5.75 Y3.4498
X8.172 Y4.453
G80 M5
G91 G28 Z0
G90
M30

Offline ger21

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Re: G code issues
« Reply #3 on: February 27, 2014, 08:51:10 PM »
What diameter tool are you using? It's having trouble with the 1/8" move for the second pass. If you make the tool diameter .125, it works correctly.
Gerry

2010 Screenset
http://www.thecncwoodworker.com/2010.html

JointCAM Dovetail and Box Joint software
http://www.g-forcecnc.com/jointcam.html
Re: G code issues
« Reply #4 on: February 28, 2014, 05:29:48 PM »
What diameter tool are you using? It's having trouble with the 1/8" move for the second pass. If you make the tool diameter .125, it works correctly.

Tool Diameter is .500"... I don't want to use a .125" end mill

I want to get away from center of tool programing so I can adjust for cutter wear.

Offline Graham Waterworth

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Re: G code issues
« Reply #5 on: March 03, 2014, 01:48:34 PM »
Try it like this :-

O0046

( PROGRAM TO CUT CIRCLE AND BOLT HOLE PATTERN)
( FEB 24 2014)
(G54 X0 Y0 Z0 IS CENTER OF CIRCLE)

G17 G20  G40 G54 G80 G90
T01 M6
G90
G0 X5.75 Y6.875
M3 S500
G43 H1 Z.5
G1 Z-.7 F20
G41 X3.25 D1
G3 X3.25 Y6.875 I2.50 J0
G1 X3.125
G3 X3.125 Y6.875 I2.624 J0
G3 X5.75 Y4.251 R2.624
G0 Z1.0
G1 G40 X0 Y0
M5
T02 M6
G91 G28 Z0
G90
G0 X9.1752 Y6.875
M3 S500
G43 H2 Z.5
G83 Z-.7 R.05 Q.5 F40
X8.172 Y9.297
X5.70 Y10.30
X3.328 Y9.297
X2.3248 Y6.875
X3.328 Y4.453
X5.75 Y3.4498
X8.172 Y4.453
G80 M5
G91 G28 Z0
G90
M30
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