I'm splitting hairs I suppose, but I'm trying to make a 3.3mm hole with a 3.125mm (1/8") end mill. It's on an angled surface, which is why this gives me pause.

In VCP, I program it to go inside the profile, and spiral down. This is the code I get, which has no spiraling until it's all the way at the bottom.

F900 XY [SET FEEDRATE FOR X AND Y]

F700 Z [SET FEEDRATE FOR Z]

G0 X10.000000 Y-6.288500

G0 Z7.000

G0 X10.000000 Y-6.288500 Z5.000000

G1 X10.000000 Y-6.288500 Z0.000000

G1 X10.000000 Y-6.288500 Z-5.000000

G1 X10.000000 Y-6.288500 Z-10.000000

G1 X10.000000 Y-6.288500 Z-15.000000

G3 X9.938500 Y-6.350000 I0.000000 J-0.061500

G3 X10.000000 Y-6.411500 I0.061500 J0.000000

G3 X10.061500 Y-6.350000 I0.000000 J0.061500

G3 X10.000000 Y-6.288500 I-0.061500 J0.000000

G0 X10.000000 Y-6.288500 Z7.000000

G53 Z0

If I make the hole bigger, it works. This is for a 4mm hole and looks like what I expect.

F900 XY [SET FEEDRATE FOR X AND Y]

F700 Z [SET FEEDRATE FOR Z]

G0 X10.000000 Y-5.938500

G0 Z7.000

G0 X10.000000 Y-5.938500 Z5.000000

G1 X10.000000 Y-5.938500 Z0.000000

G1 X9.950472 Y-5.941492 Z-0.096023

G1 X9.899572 Y-5.950943 Z-0.196209

G1 X9.848529 Y-5.967392 Z-0.299992

G1 X9.798759 Y-5.991065 Z-0.406648

G1 X9.751771 Y-6.021801 Z-0.515308

G1 X9.709025 Y-6.059026 Z-0.625000

G1 X9.671802 Y-6.101770 Z-0.734691

G1 X9.641065 Y-6.148759 Z-0.843352

G1 X9.617393 Y-6.198529 Z-0.950008

G1 X9.600943 Y-6.249572 Z-1.053791

G1 X9.591492 Y-6.300472 Z-1.153977

G1 X9.588500 Y-6.350000 Z-1.250000 etc.....

For this application I need 3.3 not 4.0

I can go down as far as 3.6 before it stops spiraling.

Anything I can do here?