Newbie Circular Interpolating

[eliot15]

Hello,

We were using a radius cutter to cut a radius on a small mold centralizer. The centralizer's diameter was 2.036", and the cutter radius is .5".

I understand the I and J addresses. The X and Y coordinate words in the G41 block represent the arc starting point, right? The J value is the centralizer radius plus 1/2 the cutter diameter away from the center of the arc. The center of the arc is part zero in this case.

What's up with line N99. G2 is still in effect 'cause its modal. So the X and Y coordinate words in line N99 represent end points of an arc starting at
X.0005 Y1.268, right? That doesn't make any sense to me.

Is this some of that "lead-out" arc style code? I'm in absolute mode, so those are absolute values, right? It doesn't seem like the cutter could move to that location without hitting the part.

I didn't get to run the code, just trying to understand it.

Any help greatly appreciated.

(.500 Radius Cutter)
S325 M3
G90 G0 X.0006 Y1.3
G43 Z1. H18 T5
Z.1
M8
G41 X.0005 Y1.268 D18 F4.
G2 I-.0005 J-1.268
N99 X.8999 Y.8933 I-.0005 J-1.268
G40 G1 X.900 Y.900
G0 Z1.
M101
G28 Y0
M30

[eliot15]

oops...

Forgot the line after the M8 and before the G41 block...

G1 Z-.477 F6.

[eliot15]

Almost looks like :

N99 X.8999 Y.8933 I-.0005 J-1.268

would be a second cutting pass. Is that possible?

[eliot15]

I installed NCPlot evaluation version from Peter Smid's book and was able to look at it.

X.8999 Y.8933 I-.0005 J-1.268

continues a short "lead-out" arc at the same distance from arc center (part zero) as the initial G2 full circle. X.8999 Y.8933 looks like its at a dead 45 degree angle from part zero in Quadrant 1 of the circles circumference.