[pieface]

Good morning folks (At least it is a snowy morning here in UK)
Running Fanuc 18i on Enshu JE60.
I have a proven program finish milling around two internal overlapping circular cavities. Works fine, no problem. Problem starts due to a fixture issue, where I need to use co-ordinate rotation to make minor correction for the fixture (This error cannot be corrected on the fixture without serious cost and downtime). When I rotate the feature, I get 041 CRC Interference error, and after experimentation, I have to reduce radius of tool by minimum 4mm for it to run (Tool radius is 12.425), but it runs round fine without the G68. Section of program posted below. There are plenty of variables at the start, as this is a 3 per load fixture and we loop to save memory, most of the variables relate to work offset selection, speeds/feeds, safety checks etc. and don't have any bearing on the milling section.
Those that are relevant are #120 (Rotation angle) this varies across each station, ranging from -0.114° min to +0.153° max, so only minor change in angle. #110=0 in this case (Optional adjustment in centre distance).
What's really confusing me, is that with no G68 line, the program runs perfectly, I don't get why the rotation should upset it as obviously all the start and end points are equally rotated, unless I have a parameter issue.
I've highlighted in BOLD the line where I get error in single block (To avoid read ahead buffer), it runs fine up to there.

Anyone seen anything like this before?
Cheers

N16M6T16(25MM - 3 FLUTE FLY MILL)
(MILL COVER FACE & GEAR CAVITY BOTTOMS)
M35
M1

T15
M52
#112=1.
#113=350.-[760.+#[#112*20.-20.+7003.]]
WHILE[#112LE3.]DO1
#114=#112
IF[#1001EQ1.]THEN#114=#112+20.
#101=315.
#102=3.*.025
#103=25.
#104=#101/[#103*3.142/1000]
IF[#104GT13000.]THEN#104=12950.
#105=#104*#102
#120=#[#112+120.]
IF[#1001EQ1.]THEN#120=#[#112+140.]
G69
G0G90G54.1P#114
G68X0Y0R#120
X-[25.4+#110]Y0S#104M3B0.G43Z#113H16
Z2.M8
(M51)
G1Z-8.8F2000
Z-[11.006+#100]F#105
X0Y0
G41X12.767Y0D16
G3X-14.733F#105Z-[11.012+#100]R13.75
G3X-14.733I14.733
G3X12.767R13.75
G40G1X0Y0

X-[25.4+#110]Y0
G41X-[38.167+#110]Y0D16
G3X-[10.667+#110]Y0R13.75
G3X-[10.667+#110]Y0I-14.733
G3X-[38.167+#110]Y0R13.75Z-10.962
G40G1X-[25.4+#110]Y0
G0Z.05

(COVER FACE )
#102=3.*.075(FEED )
#105=#104*#102
G3X-25.4Y26.75Z0R13.375S#104F#105
G3X-12.700Y-23.543R-26.75
G3X-12.700Y23.543R-26.75
G3X-25.4Y26.75R26.75
G3X-25.4Y0R13.375Z0.5
#113=10.
IF[#112EQ3.]THEN#113=350.-[760.+#[#112*20.-20.+7003.]]
G0Z#113
#112=#112+1.
END1
G69
M9
M19
G91G30X0Y0Z0M80
G90

[pieface]

Found a work around.
It only seems to be struggling with the 360° circle line using the I value, so I split that into 2 x 180° arcs and went with an R value instead, that works no problem.

Experimented with adding J0 to the G3 line, Z0 to the G68 line prior to finding that, none of which helped.

Strange!!

I think it must be a Fanuc thing.

Sorted, but would still like to understand why it failed, so please still post if you have any thoughts.

Cheers
John