[mwbridgwater]

I wrote this simple program today for finishing a slot (I've omitted the first part which is roughing.). Please see the sketch and code I wrote. One problem which I can't figure out: The finished slot measures the correct width (.280) but the length is exactly .015 short at each end (2.220 inside the ends of the full radii instead of 2.250). Using a .250 end mill with D code at .250 diameter. Funny, that the amount the ends are short is the same as the amount that the sides are over 1/4", but I don't see how that can be related. See PDF sketch: Starting at point "A", CCW loop, finishing at point "B". Gotta figure this out by the morning! Thanks for any insight.

N23 X2.3 Y0
N24 G01 Z-.5 F80.
N25 G41 D04 X2.345 Y0
N26 G03 X2.485 Y.140 I.140 J0
N27 G01 X.515
N28 G03 X.515 Y-.140 I0 J-.140
N29 G01 X2.485
N30 G03 X2.625 Y0 I0 J.140
N31 G40 G01 X2.3 M09
N32 G00 G91 G28 Z0.
N33 M30

[broby]

I wrote this simple program today for finishing a slot (I've omitted the first part which is roughing.). Please see the sketch and code I wrote. One problem which I can't figure out: The finished slot measures the correct width (.280) but the length is exactly .015 short at each end (2.220 inside the ends of the full radii instead of 2.250). Using a .250 end mill with D code at .250 diameter. Funny, that the amount the ends are short is the same as the amount that the sides are over 1/4", but I don't see how that can be related. See PDF sketch: Starting at point "A", CCW loop, finishing at point "B". Gotta figure this out by the morning! Thanks for any insight.

N23 X2.3 Y0
N24 G01 Z-.5 F80.
N25 G41 D04 X2.345 Y0
N26 G03 X2.485 Y.140 I.140 J0
N27 G01 X.515
N28 G03 X.515 Y-.140 I0 J-.140
N29 G01 X2.485
N30 G03 X2.625 Y0 I0 J.140
N31 G40 G01 X2.3 M09
N32 G00 G91 G28 Z0.
N33 M30

Hi,
At first look, it appears you are not starting your Cutter Rad Comp in the correct place.
On line N23 you are positioning to the Left of the indicated point A.
You are then using Cutter Rad Comp to the Left (G41)
I do believe that you need to have your start point on line N23 at X2.485
This will then allow the CCR to startup correctly as it positions the cutter to X2.345 Y0.
The rest of the program is correct.
Hope that helps you.
Cheer
Brian.

[dcoupar]

Did you get it figured out? What was the solution?