[Maxwell1045]

Howdy, a student here at Colorado Mesa University. currently in class have a very simple problem that can be solved in a few minutes but I have no idea what I'm doing wrong. a simple part, 4" long 1" wide .750" deep with .2" 45-degree cuts on the corners, G54 is the center of the part using a 1/2" endmill. I have a few numbers but can't seem to get the 45 right, I need help finding the correct X and Y values for start and endpoints. let me know if there's anything I can add. here's the basic start of the code. includes face op.


O1046 (MAH OP10); 1.188X1.188X3.375
G17G20;
G40G94;
G0;
G90;
G54; (center of part)
T1M6(1/2);
G43H1;
Z1.0;
;
;
G0X-3.0Y0;
G1Y.51F46.5;
X3.0;
Y.25;
X-3.0;
Y0;
X3.0;
Y-.25;
X-3.0;
Y-.51;
X3.0;
;
;(profile)
G0 X-3.0Y.75;
G1 X2.05 F46.5;
X2.5Y.3

[Jim Dawson]

Try this

(2D CONTOUR1)
M5
T1 M6
S1146 M3
G54
M8
G0 X-2.4 Y-0.05
G43 Z0.6 H1
Z0.2
G1 Z0.0394 F3.5
Z-0.7
G18 G2 X-2.35 Z-0.75 I0.05 K0. F10.4
G1 X-2.3
G17 G3 X-2.25 Y0. I0. J0.05
G1 Y0.3
G2 X-2.1768 Y0.4768 I0.25 J0.
G1 X-1.9768 Y0.6768
G2 X-1.8 Y0.75 I0.1768 J-0.1768
G1 X1.8
G2 X1.9768 Y0.6768 I0. J-0.25
G1 X2.1768 Y0.4768
G2 X2.25 Y0.3 I-0.1768 J-0.1768
G1 Y-0.3
G2 X2.1768 Y-0.4768 I-0.25 J0.
G1 X1.9768 Y-0.6768
G2 X1.8 Y-0.75 I-0.1768 J0.1768
G1 X-1.8
G2 X-1.9768 Y-0.6768 I0. J0.25
G1 X-2.1768 Y-0.4768
G2 X-2.25 Y-0.3 I0.1768 J0.1768
G1 Y0.
G3 X-2.3 Y0.05 I-0.05 J0.
G1 X-2.35
G18 G3 X-2.4 Z-0.7 I0. K0.05
G0 Z0.6
G17


M9
G53 G0 Z0.
G53 G0 X0. Y0.
M30

[Maxwell1045]

Thanks! Interesting to see how others do this. Our print actually calls for a sharp 45* cut with no radius, also how did you find the start and end pints for the 45* cut?? what math was used? Thanks for the help!

[Jim Dawson]

Thanks! Interesting to see how others do this. Our print actually calls for a sharp 45* cut with no radius, also how did you find the start and end pints for the 45* cut?? what math was used? Thanks for the help!

I cheated. I drew it up in Fusion 360 based on your description and then did the CAM work on it. Even though you see arc moves, the corners are squared off. The tool path rolls around the corner with an arc radius of 1/2 the cutter diameter. To hand write the G code, it is easiest to draw the part, offset the tool path by the radius of the cutter, then just measure the transition points and plug those numbers into your G code.

Here is the profile sketch of the part. The outer shape is the tool path using a 0.500 cutter, the inner shape is the part. The dimensions in parentheses are the transition points for a direction change based on the part and the tool.



Here is the solid model showing the tool path generated in the CAM software.



Here is the same G code without any arcs

(2D CONTOUR1)
M5
T1 M6
S1146 M3
G54
M8
G0 X-2.25 Y0.
G43 Z0.6 H1
Z0.2
G1 Z0.0394 F3.5
Z-0.75
Y0.3 F10.4
Y0.4036
X-1.9036 Y0.75
X1.9036
X2.25 Y0.4036
Y-0.3
Y-0.4036
X1.9036 Y-0.75
X-1.9036
X-2.25 Y-0.4036
Y0.
G0 Z0.6


M9
G53 G0 Z0.
G53 G0 X0. Y0.
M30