Xactmeasure nominals change from run to run.

[Jtkuyt]

I'm running version 2014, for what it's worth

I have a pair of holes I'm trying to measure. Hole 2 uses hole 1 as a datum, and the other datums are a bit awkward, but nothing ridiculous. However, 2 back-to-back runs of the same part can give me up to 0.05mm of difference between the two results. That's not the worst problem, though. The nominals that it's using to get those results is changing drastically from run to run. One run, the true position output will say the X nominal is something like 37.5mm, the next run it will say that same distance should be 13.7mm. Either way is completely disregarding actual dimensions I've put in. I've tried toggling Fit To Datums, I've used both Current Alignment and Datum Reference Frame Alignment. Just when I get a few matching reports in a row and think it's sorted, the next one will be different again. I'd like to think my alignment is solid, but obviously SOMETHING isn't right.

I can attach program excerpts and info as needed (I just figured it'd be a bit obtrusive to copy/paste the whole program if it wasn't needed)

[KIRBSTER269]

Post your Code, you use auto features? you using a CAD? are all your features to size and location? Is the sky blue? Did we go to different schools together?

[Kp61dude!]

I look forward to anything Kirby on this forum.

[Jtkuyt]

The holes being measured are auto features, yes using CAD. One hole is a different size in the CAD model than the current part, but both are to size for the nominals. Location is a definite no, as we don't have any way to verify a part besides the CMM.

Standby, I'll post code in a sec.

[Jtkuyt]

Here's the program, minus startup, Initial alignment features, move points, and formatting, plus an attached copy of a report so you can see the nominals. (I have both Xact and Legacy for the sake of comparison)

A1         =ALIGNMENT/START,RECALL:STARTUP,LIST=YES
            ALIGNMENT/LEVEL,ZPLUS,PLN1
            ALIGNMENT/END
A2         =ALIGNMENT/START,RECALL:A1,LIST=YES
            ALIGNMENT/ROTATE,XPLUS,TO,LIN1,ABOUT,ZPLUS
            ALIGNMENT/END
A3         =ALIGNMENT/START,RECALL:A2,LIST=YES
            ALIGNMENT/TRANS,XAXIS,CIR1
            ALIGNMENT/TRANS,YAXIS,CIR1
            ALIGNMENT/TRANS,ZAXIS,PLN1
            ALIGNMENT/END
            MODE/DCC
PLNK       =FEAT/PLANE,CARTESIAN,TRIANGLE
            THEO/<0.918,-2.249,0>,<0,0,1>
            ACTL/<0.917,-2.255,0.034>,<-0.0020129,0.0029771,0.9999935>
            MEAS/PLANE,4
            HIT/BASIC,NORMAL,<-10.337,-9.79,0>,<0,0,1>,<-10.34,-9.797,0.024>,USE THEO=YES
            HIT/BASIC,NORMAL,<6.06,-13.039,0>,<0,0,1>,<6.061,-13.044,0.086>,USE THEO=YES
            HIT/BASIC,NORMAL,<13.289,4.616,0>,<0,0,1>,<13.288,4.611,0.03>,USE THEO=YES
            HIT/BASIC,NORMAL,<-5.34,9.215,0>,<0,0,1>,<-5.339,9.209,-0.005>,USE THEO=YES
            ENDMEAS/
PNT1       =FEAT/POINT,CARTESIAN
            THEO/<-30.596,-18.262,-17>,<-0.0005458,-0.9999835,-0.0057203>
            ACTL/<-30.6,-18.208,-17.848>,<-0.0005458,-0.9999835,-0.0057203>
            MEAS/POINT,1,WORKPLANE
            HIT/BASIC,NORMAL,<-30.596,-18.262,-17.849>,<-0.0005458,-0.9999835,-0.0057203>,<-30.6,-18.208,-17.848>,USE THEO=YES
            ENDMEAS/
PNT2       =FEAT/POINT,CARTESIAN
            THEO/<-13.315,-18.263,-17>,<-0.0005458,-0.9999835,-0.0057203>
            ACTL/<-13.318,-18.197,-19.374>,<-0.0005458,-0.9999835,-0.0057203>
            MEAS/POINT,1,WORKPLANE
            HIT/BASIC,NORMAL,<-13.315,-18.263,-19.374>,<-0.0005458,-0.9999835,-0.0057203>,<-13.318,-18.197,-19.374>,USE THEO=YES
            ENDMEAS/
LIN2       =FEAT/LINE,CARTESIAN,UNBOUNDED,NO
            THEO/<-30.596,-18.262,-17>,<1,-0.0000411,0>
            ACTL/<-30.6,-18.208,-17.848>,<0.9961233,0.0006086,-0.0879661>
            CONSTR/LINE,BF,3D,PNT1,PNT2,,
            OUTLIER_REMOVAL/OFF,3
            FILTER/OFF,WAVELENGTH=0
CIR2       =FEAT/CONTACT/CIRCLE/DEFAULT,CARTESIAN,IN,LEAST_SQR
            THEO/<0.031,-0.008,0>,<0.0179592,-0.0057301,0.9998223>,10.398
            ACTL/<0.14,-0.044,0.008>,<-0.0033117,0.0026892,0.9999909>,10.524
            TARG/<0.031,-0.008,0>,<0.0179592,-0.0057301,0.9998223>
            START ANG=227.749,END ANG=405.449
            ANGLE VEC=<0.6777621,0.7352382,-0.0079605>
            DIRECTION=CCW
            SHOW FEATURE PARAMETERS=NO
            SHOW CONTACT PARAMETERS=YES
              NUMHITS=5,DEPTH=1.3,PITCH=0
              SAMPLE METHOD=SAMPLE_HITS
              SAMPLE HITS=3,SPACER=2
              AVOIDANCE MOVE=BOTH,DISTANCE=10
              FIND HOLE=DISABLED,ONERROR=NO,READ POS=NO
            SHOW HITS=NO
A4         =ALIGNMENT/START,RECALL:A3,LIST=YES
            ALIGNMENT/LEVEL,ZPLUS,PLNK
            ALIGNMENT/ROTATE,XPLUS,TO,LIN2,ABOUT,ZPLUS
            ALIGNMENT/TRANS,XAXIS,CIR2
            ALIGNMENT/TRANS,YAXIS,CIR2
            ALIGNMENT/TRANS,ZAXIS,PLNK
            ALIGNMENT/END
PLNG       =FEAT/PLANE,CARTESIAN,TRIANGLE
            THEO/<6.853,22.777,-0.244>,<-0.5605086,0.8280161,0.0148144>
            ACTL/<6.93,22.65,-0.245>,<-0.5609837,0.8277121,0.0137845>
            MEAS/PLANE,3
            HIT/BASIC,NORMAL,<11.372,25.679,8.584>,<-0.5605086,0.8280161,0.0148144>,<11.437,25.557,8.586>,USE THEO=YES
            HIT/BASIC,NORMAL,<-0.226,17.917,3.598>,<-0.5605086,0.8280161,0.0148144>,<-0.146,17.79,3.597>,USE THEO=YES
            HIT/BASIC,NORMAL,<9.412,24.737,-12.914>,<-0.5605086,0.8280161,0.0148144>,<9.499,24.602,-12.917>,USE THEO=YES
            ENDMEAS/
CIRM       =FEAT/CONTACT/CIRCLE/DEFAULT,CARTESIAN,IN,LEAST_SQR
            THEO/<-0.054,0.018,-2.94>,<0.0179659,-0.0057261,0.9998222>,8
            ACTL/<0.287,0.219,-3.153>,<0.0179659,-0.0057261,0.9998222>,8.12
            TARG/<-0.054,0.018,-2.94>,<0.0179659,-0.0057261,0.9998222>
            START ANG=134.8,END ANG=134.8
            ANGLE VEC=<0.6777318,0.7352661,-0.0079673>
            DIRECTION=CCW
            SHOW FEATURE PARAMETERS=NO
            SHOW CONTACT PARAMETERS=YES
              NUMHITS=7,DEPTH=1.3,PITCH=0
              SAMPLE METHOD=SAMPLE_HITS
              SAMPLE HITS=1,SPACER=2
              AVOIDANCE MOVE=BOTH,DISTANCE=10
              FIND HOLE=DISABLED,ONERROR=NO,READ POS=NO
            SHOW HITS=NO
            DATDEF/FEATURE=PLNK,K
            DATDEF/FEATURE=PLNG,G
            DATDEF/FEATURE=CIRM,M
CIR3       =FEAT/CONTACT/CIRCLE/DEFAULT,CARTESIAN,IN,LEAST_SQR
            THEO/<-26.701,-5.585,-11.509>,<0.0179655,-0.0057269,0.9998222>,14.25
            ACTL/<-26.512,-5.451,-11.487>,<0.0179655,-0.0057269,0.9998222>,14.3
            TARG/<-26.701,-5.585,-11.509>,<0.0179655,-0.0057269,0.9998222>
            START ANG=0,END ANG=360
            ANGLE VEC=<0.6777318,0.7352661,-0.0079664>
            DIRECTION=CCW
            SHOW FEATURE PARAMETERS=NO
            SHOW CONTACT PARAMETERS=YES
              NUMHITS=7,DEPTH=2,PITCH=0
              SAMPLE METHOD=SAMPLE_HITS
              SAMPLE HITS=1,SPACER=2
              AVOIDANCE MOVE=BOTH,DISTANCE=10
              FIND HOLE=DISABLED,ONERROR=NO,READ POS=NO
            SHOW HITS=NO
CIR4       =FEAT/CONTACT/CIRCLE/DEFAULT,CARTESIAN,IN,LEAST_SQR
            THEO/<-27.15,-5.442,-36.468>,<0.0179655,-0.0057269,0.9998222>,14.25
            ACTL/<-26.957,-5.334,-36.471>,<0.0179655,-0.0057269,0.9998222>,14.293
            TARG/<-27.15,-5.442,-36.468>,<0.0179655,-0.0057269,0.9998222>
            START ANG=0,END ANG=360
            ANGLE VEC=<0.6777318,0.7352661,-0.0079664>
            DIRECTION=CCW
            SHOW FEATURE PARAMETERS=NO
            SHOW CONTACT PARAMETERS=YES
              NUMHITS=7,DEPTH=1,PITCH=0
              SAMPLE METHOD=SAMPLE_HITS
              SAMPLE HITS=0,SPACER=2
              AVOIDANCE MOVE=BOTH,DISTANCE=10
              FIND HOLE=DISABLED,ONERROR=NO,READ POS=NO
            SHOW HITS=NO
CYL1       =FEAT/CYLINDER,CARTESIAN,IN,LEAST_SQR,NO
            THEO/<-26.952,-5.505,-25.488>,<-0.0179655,0.0057269,-0.9998222>,14.25,23.963
            ACTL/<-26.762,-5.384,-25.479>,<-0.0178157,0.0046279,-0.9998306>,14.296,24.003
            CONSTR/CYLINDER,BF,CIR3,CIR4,,
CFLOC1 =POSITION : CIRM
            FEATCTRLFRAME/SHOWNOMS=NO,SHOWPARAMS=YES,SHOWEXPANDED=YES
            CADGRAPH=OFF,REPORTGRAPH=OFF,TEXT=OFF,MULT=10.00,ARROWDENSITY=100,OUTPUT=BOTH,UNITS=MM
            COMPOSITE=NO,FIT TO DATUMS=NO,DEV PERPEN CENTERLINE=ON,OUTPUT ALIGNMENT=Current Alignment
            CUSTOMIZED DRF=NO
            STANDARDTYPE=CUSTOM
              SIZE TOLERANCES/1,DIAMETER,8,0.25,0
              PRIMARY DIMENSION/POSITION,DIAMETER,0.25,MMC,G,K,<dat>
              SECONDARY DIMENSION/<Dim>,<tol>,<MC>,<dat>,<dat>,<dat>
              NOTE/FCFLOC1
            FEATURES/CIRM,,
FCFLOC2 =POSITION : CYL1
            FEATCTRLFRAME/SHOWNOMS=NO,SHOWPARAMS=YES,SHOWEXPANDED=YES
            CADGRAPH=OFF,REPORTGRAPH=OFF,TEXT=OFF,MULT=10.00,ARROWDENSITY=100,OUTPUT=REPORT,UNITS=MM
            COMPOSITE=NO,FIT TO DATUMS=NO,DEV PERPEN CENTERLINE=ON,OUTPUT ALIGNMENT=Current Alignment
            CUSTOMIZED DRF=NO
            STANDARDTYPE=CUSTOM
              SIZE TOLERANCES/1,DIAMETER,14.25,0.1,0.1
              PRIMARY DIMENSION/POSITION,DIAMETER,0.25,MMC,<PZ>,<len>,G,K,M,<MC>
              SECONDARY DIMENSION/<Dim>,<tol>,<MC>,G,K,<dat>
              NOTE/FCFLOC2
            FEATURES/CYL1,,
DIM LOC79= POSITION OF CIRCLE CIRM  UNITS=MM ,$
GRAPH=OFF  TEXT=OFF  MULT=10.00  OUTPUT=REPORT  FIT TO DATUMS=OFF  DEV PERPEN CENTERLINE=OFF  DISPLAY=DIAMETER
AX    NOMINAL       +TOL       -TOL      BONUS       MEAS        DEV     OUTTOL
Y       0.018                                       0.219      0.201           
Z      -2.940                                      -3.153     -0.214           
DF      8.000      0.250      0.000      0.120      8.120      0.120      0.000 ----#----
TP        MMC      0.010                 0.120      0.587      0.587      0.457 -------->
END OF DIMENSION LOC79
DIM LOC80= POSITION OF CYLINDER CYL1  USE AXIS=AVERAGE  REF LENGTH=0.000  UNITS=MM ,$
GRAPH=OFF  TEXT=OFF  MULT=10.00  OUTPUT=REPORT  FIT TO DATUMS=OFF  DEV PERPEN CENTERLINE=OFF  DISPLAY=DIAMETER
AX    NOMINAL       +TOL       -TOL      BONUS       MEAS        DEV     OUTTOL
Y      -5.505                                      -5.384      0.122           
Z     -25.488                                     -25.479      0.009           
DF     14.250      0.100      0.100      0.146     14.296      0.046      0.000 ------#--
TP        MMC      0.010                 0.146      0.244      0.244      0.088 -------->
END OF DIMENSION LOC80

[KIRBSTER269]

YUCK!!!!!!!! first of all square up some of your planes, circles, and other stuff. Your vector hits on your features are telling DMIS to take your hits awkward. Plane vector hits 0,0,1. Some of your circles.

CIR3       =FEAT/CONTACT/CIRCLE/DEFAULT,CARTESIAN,IN,LEAST_SQR
            THEO/<-26.701,-5.585,-11.509>,<[COLOR=#FF0000]0.0179655,-0.0057269,0.9998222[/COLOR]>,14.25
            ACTL/<-26.512,-5.451,-11.487>,<0.0179655,-0.0057269,0.9998222>,14.3
            TARG/<-26.701,-5.585,-11.509>,<[COLOR=#FF0000]0.0179655,-0.0057269,0.9998222[/COLOR]>
            START ANG=0,END ANG=360
            ANGLE VEC=<0.6777318,0.7352661,-0.0079664>
            DIRECTION=CCW
            SHOW FEATURE PARAMETERS=NO
            SHOW CONTACT PARAMETERS=YES
              NUMHITS=7,DEPTH=2,PITCH=0
              SAMPLE METHOD=SAMPLE_HITS
              SAMPLE HITS=1,SPACER=2
              AVOIDANCE MOVE=BOTH,DISTANCE=10
              FIND HOLE=DISABLED,ONERROR=NO,READ POS=NO
            SHOW HITS=NO
CIR3       =FEAT/CONTACT/CIRCLE/DEFAULT,CARTESIAN,IN,LEAST_SQR
            THEO/<-26.701,-5.585,-11.509>,<[COLOR=#FF0000]0,0,1[/COLOR]>,14.25
            ACTL/<-26.512,-5.451,-11.487>,<0.0179655,-0.0057269,0.9998222>,14.3
            TARG/<-26.701,-5.585,-11.509>,<[COLOR=#FF0000]0,0,1[/COLOR]>
            START ANG=0,END ANG=360
            ANGLE VEC=<0.6777318,0.7352661,-0.0079664>
            DIRECTION=CCW
            SHOW FEATURE PARAMETERS=NO
            SHOW CONTACT PARAMETERS=YES
              NUMHITS=7,DEPTH=2,PITCH=0
              SAMPLE METHOD=SAMPLE_HITS
              SAMPLE HITS=1,SPACER=2
              AVOIDANCE MOVE=BOTH,DISTANCE=10
              FIND HOLE=DISABLED,ONERROR=NO,READ POS=NO
            SHOW HITS=NO

Go through the rest of the program and clean up your vectors.

[Jtkuyt]

Will do.

[Sora5]

Keep in mind when positioning Cylinders, Xact measure will always report the Worse Axis. You can see this on the report as (End PT) or (Start PT) next to the feature in the deviation section. You are constructing a cylinder from two circles that have different X and Y nominals. This will cause your reporting nominal to change depending on which circle has a higher deviation. This behavior is normal. In your legacy dimension, you're reporting the average axis.

[Jtkuyt]

Keep in mind when positioning Cylinders, Xact measure will always report the Worse Axis. You can see this on the report as (End PT) or (Start PT) next to the feature in the deviation section. You are constructing a cylinder from two circles that have different X and Y nominals. This will cause your reporting nominal to change depending on which circle has a higher deviation. This behavior is normal. In your legacy dimension, you're reporting the average axis.

If I change the dimension to measure only one circle it does appear to be consistent. I'll run a bunch of parts and see if this clears it up.