I've got a problem with groove milling. It seems to work if I look at the screen while the mashine is running but when i messure the groove I find that the bottom of the the groove has a smaller with (0,1mm smaller). It's probably an issue with the radius compensation. Perhaps the issue starts when the roughing is done and the finnishing starts, when I go from Y2.4 to Y-2.5. I use a diameter 4mm endmill. The width of the finniched groove si suppose to be 5mm. There is two identical paralell grooves.
In the awesome illustration bellow the orange arrows point at the groove while the yellow arrow point at the smaller with. Just to get an idea of what is going on. The inner diameter of the (hollow) work pice is 17.1mm.
I use a Nakamura Tome WT-300

Attachment 338458

And the code...
Code:
M120(WAIT) 
 
N70M91(PINNFRAAS MAX  DIA 4.8, GLOM EJ RADIEKOMPENSERING ) 
G19
G28H0
G0C90
G0G40G97G99T0909M89S3600 
G0Z5 
G0G41X20.3Y-2.5M7
G1Z-16F0.1 
G3Z-18.5Y0R2.5 
G3Z-16Y2.5R2.5 
G1Z5 
G0G40Y0X31 
G0C0X30.5Z-6.9 
(START 1)
G1X24.3F0.02 
G1G41Y-2.4F0.1 
G1Z-42.1 
G3Z-44.5Y0R2.4 
G3Z-42.1Y2.4R2.4 
G1X23.3Z-6.9 
G3Z-4.5Y0R2.4
G3Z-6.9Y-2.4R2.4(SLUT 1.1) 
G1X22.2Z-42.1
G3Z-44.5Y0R2.4 
G3Z-42.1Y2.4R2.4 
G1X21.2Z-6.9 
G3Z-4.5Y0R2.4
G3Z-6.9Y-2.4R2.4(SLUT 1.2) 
G1X20.2Z-42.1
G3Z-44.5Y0R2.4 
G3Z-42.1Y2.4R2.4 
G1X19.2Z-6.9 
G3Z-4.5Y0R2.4
G3Z-6.9Y-2.4R2.4(SLUT 1.3) 
G1X18.2Z-42.1
G3Z-44.5Y0R2.4 
G3Z-42.1Y2.4R2.4 
G1X17.2Z-6.9 
G3Z-4.5Y0R2.4
G3Z-6.9Y-2.4R2.4(SLUT 1.4) 
G1X16.2Z-42.1
G3Z-44.5Y0R2.4 
G3Z-42.1Y2.4R2.4 
G1X14.6Z-6.9 
G3Z-4.5Y0R2.4
G3Z-6.9Y-2.4R2.4(SLUT 1.5) 
G1Z-42.1 
G3Z-44.5Y0R2.4 
G3Z-42.1Y2.4R2.4 
G1Z-6.9
G1Y-2.5F0.06(FINFRAASNING 1 BOORJAN) 
G1Z-42 
G3Z-44.5Y0R2.5 
G3Z-42Y2.5R2.5 
G1Z-7
G3Z-4.5Y0R2.5
G3Z-7Y-2.5R2.5 
G1Z-13 
G1Y0(FINFRAASNING 1 SLUT)
G1G40X33Y0F0.2 
G28U0V0
G0G40G97G99T0909M89S3600 
M91
(SLUT 1) 
G0C180X30.5Z-6.9M7 
(START 2)
G1X24.3F0.02 
G1G41Y-2.4 
G1Z-42.1F0.1 
G3Z-44.5Y0R2.4 
G3Z-42.1Y2.4R2.4 
G1X23.3Z-6.9 
G3Z-4.5Y0R2.4
G3Z-6.9Y-2.4R2.4(SLUT 2.1) 
G1X22.2Z-42.1
G3Z-44.5Y0R2.4 
G3Z-42.1Y2.4R2.4(HAR)
G1X21.2Z-6.9 
G3Z-4.5Y0R2.4
G3Z-6.9Y-2.4R2.4(SLUT 2.2) 
G1X20.2Z-42.1
G3Z-44.5Y0R2.4 
G3Z-42.1Y2.4R2.4 
G1X19.2Z-6.9 
G3Z-4.5Y0R2.4
G3Z-6.9Y-2.4R2.4(SLUT 2.3) 
G1X18.2Z-42.1
G3Z-44.5Y0R2.4 
G3Z-42.1Y2.4R2.4 
G1X17.2Z-6.9 
G3Z-4.5Y0R2.4
G3Z-6.9Y-2.4R2.4(SLUT 2.4) 
G1X16.2Z-42.1
G3Z-44.5Y0R2.4 
G3Z-42.1Y2.4R2.4 
G1X14.6Z-6.9 
G3Z-4.5Y0R2.4
G3Z-6.9Y-2.4R2.4(SLUT 2.5) 
G1Z-42.1 
G3Z-44.5Y0R2.4 
G3Z-42.1Y2.4R2.4 
G1Z-6.9
G1Y-2.5F0.06(FINFRAASNING 2 BOORJAN) 
G1Z-42 
G3Z-44.5Y0R2.5 
G3Z-42Y2.5R2.5 
G1Z-7
G3Z-4.5Y0R2.5
G3Z-7Y-2.5R2.5 
G1Z-13 
G1Y0(FINFRAASNING 2 SLUT)
G1G40X30Y0F0.5 
G0X100Z5M9 
M90
G28U0V0
G18
If I can only get this to work I have made a timesaving macro version of the same program. It's almost identical and gives the same issues with the width of the groove. (sorry about the Swedish comments
Code:
M120(WAIT) 
 
 
(FUNGERAR ENBART VID BEARBETNING MED ETT DAAR SPAARETS BOORJAN HAR ETT HOOGRE Z VAARDE AAN SLUTET )
#1=-4.5(OK ATT AANDRA)(Z-VAARDE BOORJAN, TOTAL SPAARLAANGD)
#2=-44.5(OK ATT AANDRA)(Z-VAARDE SLUT, TOTAL SPAARLAANGD)
#3=0.1(OK ATT AANDRA)(SPARAS TILL FINKOORNINGEN, ANGE ETT PLUSVAARDE EX #3=0.1)
#4=2.5(OK ATT AANDRA)(SPARETS RADIE, EX. 5MM BRETT SPAAR= RADIE 2.5) 
#5=28(OK ATT AANDRA)(GAAR TILL DETTA X-VDRDE NDR CYKELN BOORJAR, KAN BOORJA I LUFTEN CA 0.5MM OOVER, ELLER BOORJA I INGREPP.)
#6=0.02(OK ATT AANDRA)(MATNING I X NAAR FRAASEN GAAR TILL #5)
#7=0(OK ATT AANDRA)(C VAARDET DAR FOORSTA SPAARET SKALL KOORAS)
#8=2.5(OK ATT AANDRA)(EXTRA LANGD I Z FOOR ATT INTE LAMNA EN KANT VID FINKOORNING) 
#9=0.1(OK ATT AANDRA)(MATNING UNDER GROVCYKELN)
#13=1(OK ATTT AANDRA)(DIAMENTRAL MINSKNING I X FVR VARJE STEG REKOMMENDERAT VDRDE -1)
#14=15(OK ATT AANDRA)(X VAARDE DAR CYKELN SLUTAR/BOTTEN PAA SPAARET) 
#20=0(OK ATT ANDRAA)(Y-VAARDE MITT I SPARET, STANDARDVAARDE=0) 
#21=30.5(OK ATT AANDRA)(X-VAARDE INNAN BEARBETNING BOORJAR, OBS  MESTE VARA FRITT/OVANFOOR DETALJEN) 
#22=72(OK ATT AANDRA)(BLOCKNUMMER SOM PROGRAMMET HOPPAR TILL EFTER FINCYKELN, EX #22=65 HOPPAR TILL N65) 
#23=2(OK ATT AANDRA)(ANTAL SPAAR MED JDMN DELNING SOM SKALL FRAASAS, VAARDET FAAR EJ VARA 0) 
#25=71(OK ATT AANDRA)(BLOCKNUMMER SOM GROVCYKELN STARTAR PAA)
 
 
 
(AANDRA EJ DESSA  DE ANVAANDS TILL AUTOMATISKA UTRAAKNINGAR )
#24=0(ROOR EJ)(RAKNAR ANTALET SPAR SOM KOORTS) 
#26=360/#23(ROOR EJ)(RAAKNAR UT DELNINGEN OM FLER AAN 1 SPAAR SKALL KOORAS)
#27=#26*#24(ROOR EJ)(RAKNAR UT VAR NAASTA SPAR SKALL FRAASAS)
#16=1(ROOR EJ, RAAKNAR ANTALET GROVCYKLER) 
 
N70M91(PINNFRAAS, GLOM EJ RADIEKOMPENSERING )
G19
G28H0
G0C90
G0G40G97G99T0909M89S3600 
G0Z5 
G0G41X20.3Y-2.5M7
G1Z-16F0.12
G3Z-18.5Y0R2.5 
G3Z-16Y2.5R2.5 
G1Z5 
G0G40Y0X31 
G0C#7(STALL C VAARDET DAR FOORSTA SPAARET SKALL KOORAS)
N71(NUMMER DAAR CYKELN BVRJAR, MAASTE STAAMMA MED #25) 
G0X#21Y#20Z[#1-#4+#3]
G1X#5F#6 
WHILE[[#5-#13*#16]GT#14]DO1
G1G41Y[-#4+#3]F#9
(START GROVCYKEL)
G1X[#5-#13*#16]Z[#2+#4-#3] 
#16=#16+1
G3Z#2Y#20R[#4-#3]
G3Z[#2+#4-#3]Y[#4-#3]R[#4-#3]
G1X[#5-#13*#16]Z[#1-#4+#3] 
G3Z#1Y#20R[#4-#3]
G3Z[#1-#4+#3]Y[-#4+#3]R[#4-#3](SLUT) 
#16=#16+1
END1 
 
G1X#14Z[#2+#4-#3]F#9 
G3Z#2Y#20R[#4-#3]
G3Z[#2+#4-#3]Y[#4-#3]R[#4-#3]
G1Z[#1-#4+#3]
G1G40Y#20
(G3Z#1Y#20R[#4-#3])
(G3Z[#1-#4+#3]Y[-#4+#3]R[#4-#3]) 
 
WHILE[[#5-#13*#16]LE#14]DO2
(START FINKOORNING)
G1G41Z[#1-#4]Y-#4F#9 
G1X#14 
G1Z[#2+#4] 
G3Z#2Y#20R#4 
G3Z[#2+#4]Y#4R#4 
G1Z[#1-#4] 
G3Z#1Y#20R#4 
G3Z[#1-#4]Y[-#4]R#4
G1Z[#1-#4-#8]
#16=1
#24=#24+1
G1G40Y#20
G0X#21 
IF[#24EQ#23]GOTO#22(OM ALLA SPAAR AR KORDA, HOPPA TILL SLUTET) 
G0H[#26*#24] 
GOTO#25
END2 
N72(NUMMER DAAR CYKELN SLUTAR, MAASTE STAAMMA MED #22) 
M90
M9 
G28U0V0
G18