CYL_A =FEAT/CYLINDER,CARTESIAN,IN,LEAST_SQR,NO THEO/<0,0,-21>,<0,0,-1>,7.75,4 ACTL/<0.0055,0.0007,-20.9971>,<-0.0001267,-0.000003,-1>,7.7542,4.01 CONSTR/CYLINDER,BF,PNTB1,PNTB2,PNTB3,PNTB4,PNTB5,PNTB6,PN TB7,PNTB8,PNTB9,PNTB10,PNTB11,PNTB12,PNTB13,PNTB14 ,PNTB15,PNTB16,PNTB17,PNTB18,, AL_REF_A =ALIGNMENT/START,RECALL:A_PIECE,LIST=YES ALIGNMENT/LEVEL,ZMINUS,CYL_A ALIGNMENT/ROTATE,XPLUS,TO,LIN1,ABOUT,ZMINUS ALIGNMENT/TRANS,XAXIS,CYL_A ALIGNMENT/TRANS,YAXIS,CYL_A ALIGNMENT/TRANS,ZAXIS,PLN2 ALIGNMENT/END
This is my alignment on a cylinde constracted from points on Z axis at -19 / -21 / -23 as Z coordinates. Keep in mind that I have points at around 60 degs on the left and another 60 degs on the right "forming" incomplete inner part circles since there is material missing north and south side of the part. This is my datum and seems to be consistent as a cylinder both at cylindricity and diameter.
In any case. I have 6 "semi" circles on the outside to form 3 circles ( I am probing left and right again of the part) at Z values -5 / -12.5 / -18
CER7 =FEAT/CONTACT/CIRCLE/DEFAULT,CARTESIAN,OUT,LEAST_SQR THEO/<V0,V0,-5>,<V0,V0,1>,12.86,0 ACTL/<-0.0293,-0.0004,-5>,<0,0,1>,12.8863,0 TARG/<V0,V0,-5>,<V0,V0,1> START ANG=-50,END ANG=230 ANGLE VEC=<V0,0+1,V0> DIRECTION=CW SHOW FEATURE PARAMETERS=NO SHOW CONTACT PARAMETERS=YES NUMHITS=5,DEPTH=0,PITCH=0 SAMPLE METHOD=SAMPLE_HITS SAMPLE HITS=0,SPACER=0 AVOIDANCE MOVE=NO,DISTANCE=10 FIND HOLE=DISABLED,ONERROR=NO,READ POS=NO SHOW HITS=YES HIT/BASIC,<5.0669,3.9587,-5>,<0.7880108,0.6156615,0>,<5.0623,3.9473,-4.9989> HIT/BASIC,<6.0797,2.0934,-5>,<0.9455186,0.3255682,0>,<6.0663,2.092,-4.9997> HIT/BASIC,<6.43,0,-5>,<1,0,0>,<6.4121,0.001,-5.0028> HIT/BASIC,<6.0797,-2.0934,-5>,<0.9455186,-0.3255682,0>,<6.0669,-2.0893,-4.9973> HIT/BASIC,<5.0669,-3.9587,-5>,<0.7880108,-0.6156615,0>,<5.0621,-3.9488,-4.9983> ENDMEAS/ CER8 =FEAT/CONTACT/CIRCLE/DEFAULT,CARTESIAN,OUT,LEAST_SQR THEO/<V0,V0,-12.5>,<V0,V0,1>,12.86,0 ACTL/<-0.02,-0.0008,-12.5>,<0,0,1>,12.8713,0 TARG/<V0,V0,-12.5>,<0,0,1> START ANG=0-35,END ANG=0+35 ANGLE VEC=<V0,V0,1> DIRECTION=CCW SHOW FEATURE PARAMETERS=NO SHOW CONTACT PARAMETERS=YES NUMHITS=5,DEPTH=0,PITCH=0 SAMPLE METHOD=SAMPLE_HITS SAMPLE HITS=0,SPACER=0 AVOIDANCE MOVE=NO,DISTANCE=10 FIND HOLE=DISABLED,ONERROR=NO,READ POS=NO SHOW HITS=YES HIT/BASIC,<5.3927,-3.502,-12.5>,<0.8386706,-0.544639,0>,<5.3837,-3.4963,-12.5014> HIT/BASIC,<6.1652,-1.8262,-12.5>,<0.9588197,-0.2840153,0>,<6.1528,-1.8214,-12.502> HIT/BASIC,<6.43,0,-12.5>,<1,0,0>,<6.4156,-0.0032,-12.4938> HIT/BASIC,<6.1652,1.8262,-12.5>,<0.9588197,0.2840153,0>,<6.1522,1.8219,-12.5004> HIT/BASIC,<5.3927,3.502,-12.5>,<0.8386706,0.544639,0>,<5.3844,3.4934,-12.4991> ENDMEAS/ CER9 =FEAT/CONTACT/CIRCLE/DEFAULT,CARTESIAN,OUT,LEAST_SQR THEO/<V0,V0,-18>,<V0,V0,1>,12.86,0 ACTL/<-0.0233,-0.0013,-18>,<0,0,1>,12.8753,0 TARG/<V0,V0,-18>,<V0,V0,1> START ANG=0-50,END ANG=230+0 ANGLE VEC=<V0,0+1,0+0> DIRECTION=CW SHOW FEATURE PARAMETERS=NO SHOW CONTACT PARAMETERS=YES NUMHITS=5,DEPTH=0,PITCH=0 SAMPLE METHOD=SAMPLE_HITS SAMPLE HITS=0,SPACER=0 AVOIDANCE MOVE=NO,DISTANCE=10 FIND HOLE=DISABLED,ONERROR=NO,READ POS=NO SHOW HITS=YES HIT/BASIC,<5.0669,3.9587,-18>,<0.7880108,0.6156615,0>,<5.0576,3.951,-18.0043> HIT/BASIC,<6.0797,2.0934,-18>,<0.9455186,0.3255682,0>,<6.0667,2.0903,-18.0007> HIT/BASIC,<6.43,0,-18>,<1,0,0>,<6.4135,0.0017,-17.9992> HIT/BASIC,<6.0797,-2.0934,-18>,<0.9455186,-0.3255682,0>,<6.0661,-2.089,-18.0017> HIT/BASIC,<5.0669,-3.9587,-18>,<0.7880108,-0.6156615,0>,<5.0593,-3.9529,-17.9999> ENDMEAS/ MOVE/POINT,NORMAL,<10,-7,8> MOVE/POINT,NORMAL,<-10,-7,8> CER10 =FEAT/CONTACT/CIRCLE/DEFAULT,CARTESIAN,OUT,LEAST_SQR THEO/<V0,V0,-5>,<V0,V0,1>,12.86,0 ACTL/<0,0,-5>,<0,0,1>,12.86,0 TARG/<V0,V0,-5>,<0,0,1> START ANG=0+230,END ANG=0+130 ANGLE VEC=<V0,V0,1> DIRECTION=CW SHOW FEATURE PARAMETERS=NO SHOW CONTACT PARAMETERS=YES NUMHITS=5,DEPTH=0,PITCH=0 SAMPLE METHOD=SAMPLE_HITS SAMPLE HITS=0,SPACER=0 AVOIDANCE MOVE=NO,DISTANCE=10 FIND HOLE=DISABLED,ONERROR=NO,READ POS=NO SHOW HITS=YES HIT/BASIC,<-4.3025,-4.7784,-5>,<-0.6691306,-0.7431448,0>,<-4.3025,-4.7784,-5> HIT/BASIC,<-5.8741,-2.6153,-5>,<-0.9135455,-0.4067366,0>,<-5.8741,-2.6153,-5> HIT/BASIC,<-6.43,0,-5>,<-1,0,0>,<-6.43,0,-5> HIT/BASIC,<-5.8741,2.6153,-5>,<-0.9135455,0.4067366,0>,<-5.8741,2.6153,-5> HIT/BASIC,<-4.3025,4.7784,-5>,<-0.6691306,0.7431448,0>,<-4.3025,4.7784,-5> ENDMEAS/ CER11 =FEAT/CONTACT/CIRCLE/DEFAULT,CARTESIAN,OUT,LEAST_SQR THEO/<V0,V0,-12.5>,<V0,V0,1>,12.86,0 ACTL/<0,0,-12.5>,<0,0,1>,12.8223,0 TARG/<V0,V0,-12.5>,<0,0,1> START ANG=0+45,END ANG=0+115 ANGLE VEC=<V0,0+1,0> DIRECTION=CCW SHOW FEATURE PARAMETERS=NO SHOW CONTACT PARAMETERS=YES NUMHITS=5,DEPTH=0,PITCH=0 SAMPLE METHOD=SAMPLE_HITS SAMPLE HITS=0,SPACER=0 AVOIDANCE MOVE=NO,DISTANCE=10 FIND HOLE=DISABLED,ONERROR=NO,READ POS=NO SHOW HITS=YES HIT/BASIC,<-4.7026,4.3852,-12.5>,<-0.7313537,0.6819984,0>,<-4.8833,4.9793,-12.3707> HIT/BASIC,<-5.7544,2.8691,-12.5>,<-0.8949344,0.4461978,0>,<-5.9313,3.4675,-12.2888> HIT/BASIC,<-6.3323,1.1166,-12.5>,<-0.9848078,0.1736482,0>,<-6.5055,1.7185,-12.1912> HIT/BASIC,<-6.3887,-0.7279,-12.5>,<-0.9935719,-0.1132032,0>,<-6.557,-0.1211,-12.1076> HIT/BASIC,<-5.9188,-2.5124,-12.5>,<-0.9205049,-0.3907311,0>,<-6.0848,-1.8983,-12.0174> ENDMEAS/ CER12 =FEAT/CONTACT/CIRCLE/DEFAULT,CARTESIAN,OUT,LEAST_SQR THEO/<V0,V0,-18>,<V0,V0,1>,12.86,0 ACTL/<-0.1875,0.3366,-17.649>,<0.0018237,0.0512188,0.9986858>,12.8411,0 TARG/<V0,V0,-18>,<0,0,1> START ANG=0+220,END ANG=0+140 ANGLE VEC=<V0,V0,1> DIRECTION=CW SHOW FEATURE PARAMETERS=NO SHOW CONTACT PARAMETERS=YES NUMHITS=5,DEPTH=0,PITCH=0 SAMPLE METHOD=SAMPLE_HITS SAMPLE HITS=0,SPACER=0 AVOIDANCE MOVE=NO,DISTANCE=10 FIND HOLE=DISABLED,ONERROR=NO,READ POS=NO SHOW HITS=YES HIT/BASIC,<-5.0669,-3.9587,-18>,<-0.7880108,-0.6156615,0>,<-5.2411,-3.6184,-17.4386> HIT/BASIC,<-6.0797,-2.0934,-18>,<-0.9455186,-0.3255682,0>,<-6.253,-1.7646,-17.533> HIT/BASIC,<-6.43,0,-18>,<-1,0,0>,<-6.6082,0.32,-17.6444> HIT/BASIC,<-6.0797,2.0934,-18>,<-0.9455186,0.3255682,0>,<-6.2634,2.4101,-17.7432> HIT/BASIC,<-5.0669,3.9587,-18>,<-0.7880108,0.6156615,0>,<-5.2594,4.2687,-17.841> ENDMEAS/ MOVE/POINT,NORMAL,<-10,7,8> Ø12_86_5 =FEAT/CIRCLE,CARTESIAN,OUT,LEAST_SQR,YES THEO/<-0.0298,-0.026,-4.95>,<-0.0004096,-0.0006184,0.9999997>,12.86 ACTL/<-0.0067,-0.0001,-4.9997>,<0,0,1>,12.8529 CONSTR/CIRCLE,BF,2D,CER10.HITS[1..CER10.NUMHITS],CER7.HITS[1..CER7.NUMHITS],, OUTLIER_REMOVAL/OFF,3 FILTER/OFF,UPR=0 Ø12_86_12_5=FEAT/CIRCLE,CARTESIAN,OUT,LEAST_SQR,YES THEO/<-0.0298,-0.026,-4.95>,<-0.0004096,-0.0006184,0.9999997>,12.86 ACTL/<-0.1132,0.2985,-12.3472>,<0,0,1>,13.0627 CONSTR/CIRCLE,BF,2D,CER11.HITS[1..CER11.NUMHITS],CER8.HITS[1..CER8.NUMHITS],, OUTLIER_REMOVAL/OFF,3 FILTER/OFF,UPR=0 Ø12_86_18 =FEAT/CIRCLE,CARTESIAN,OUT,LEAST_SQR,YES THEO/<-0.0298,-0.026,-4.95>,<-0.0004096,-0.0006184,0.9999997>,12.86 ACTL/<-0.095,0.1678,-17.8206>,<0,0,1>,13.0068 CONSTR/CIRCLE,BF,2D,CER12.HITS[1..CER12.NUMHITS],CER9.HITS[1..CER9.NUMHITS],, OUTLIER_REMOVAL/OFF,3 FILTER/OFF,UPR=0
No problem with their circularity and diameter either. The issue comes with the repeatability of the circles that are the furthest away from the probings of my datum A, meaning circle -5 and -12.5
The -5 one has terrible repeatability in terms of true position with 0.03mm range of measurements. This is not the case with my circle at -18 which is constructed with the same logic and it is basicly the same tool that is creating it in the CNC machine and same probes and everything in CMM.
What am I missing? Where is the mistake? Could it be the level on a cylinder and how the 2d circle is projected? Does this justify the dispersion? I am not moving the part between the measurements and all other locations / positions / features are consistent.
DIM LOC_0_05_12_86_HAUT_A= POSITION OF CIRCLE Ø12_86_5 UNITS=MM ,$ GRAPH=OFF TEXT=OFF MULT=10.00 OUTPUT=BOTH FIT TO DATUMS=OFF DEV PERPEN CENTERLINE=OFF DISPLAY=DIAMETER AX NOMINAL +TOL -TOL BONUS MEAS DEV OUTTOL X V0 -0.0067 -0.0067 Y V0 -0.0001 -0.0001 DF 12.8600 0.0500 0.0500 12.8529 -0.0071 0.0000 #- TP RFS 0.0500 0.0000 0.0133 0.0133 0.0000 #- END OF DIMENSION LOC_0_05_12_86_HAUT_A DIM LOC_0_05_12_86_MILIEU_A= POSITION OF CIRCLE Ø12_86_12_5 UNITS=MM ,$ GRAPH=OFF TEXT=OFF MULT=10.00 OUTPUT=BOTH FIT TO DATUMS=OFF DEV PERPEN CENTERLINE=OFF DISPLAY=DIAMETER AX NOMINAL +TOL -TOL BONUS MEAS DEV OUTTOL X V0 -0.1135 -0.1135 Y V0 0.2984 0.2984 DF 12.8600 0.0500 0.0500 13.0627 0.2027 0.1527 -> TP RFS 0.0500 0.0000 0.6386 0.6386 0.5886 -> END OF DIMENSION LOC_0_05_12_86_MILIEU_A DIM LOC_0_05_12_86_BAS_A= POSITION OF CIRCLE Ø12_86_18 UNITS=MM ,$ GRAPH=OFF TEXT=OFF MULT=10.00 OUTPUT=BOTH FIT TO DATUMS=OFF DEV PERPEN CENTERLINE=OFF DISPLAY=DIAMETER AX NOMINAL +TOL -TOL BONUS MEAS DEV OUTTOL X V0 -0.0951 -0.0951 Y V0 0.1677 0.1677 DF 12.8600 0.0500 0.0500 13.0068 0.1468 0.0968 -> TP RFS 0.0500 0.0000 0.3856 0.3856 0.3356 -> END OF DIMENSION LOC_0_05_12_86_BAS_A
Thanks in advance for your answers and time.
