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Constructing features with scan data

I'm trying to construct a width feature using scan data. I've used two patch scans on opposing planar surfaces, and constructed planes from each scan. But when I try to construct a 3D width feature--either with the constructed planes, or with the individual hits from the scans--my width feature is wider than the part by the diameter of my probe tip. The only way I get the correct size is to construct from the planes using BF. If I use BFRE, the construction uses ball-center data, not surface data. Am I doing something wrong?

I'm new to scanning, and I'm still working offline at this point. I want to get this ironed out before I take it to a machine.

SCN1       =FEAT/SCAN,PATCH,NUMBER OF HITS=89            ,SHOW HITS=NO,SHOWALLPARAMS=YES
            EXEC MODE=NORMAL, NOMS MODE=FIND NOMS,CLEARPLANE=NO,SINGLE POINT=NO,THICKNESS=0
            FINDNOMS=0.1,SELECTEDONLY=NO,USEBESTFIT=NO,PROBECOMP=YES,AVOIDANCE MOVE=YES,DISTANCE=0,CAD Compensation=NO
            DIR1=VARIABLE,MAX INCR=0.05,MIN INCR=0.01,MAX ANGLE=2,MIN ANGLE=1
            DIR2=LINE,INCR=0.2,AXIS=X
            HITTYPE=VECTOR
            INITVEC=0,-1,0
            DIRVEC=1,0,0
            CUTVEC=0,0,-1
            ENDVEC=0,-1,0
            PLANEVEC=1,0,0
            POINT1=0.08,0,-3.64
            POINT2=0.92,0,-3.64
            POINT3=0.92,0,-4.44
            POINT4=0.08,0,-4.44
            MEAS/SCAN
            BASICSCAN/LINE,NUMBER OF HITS=17,SHOW HITS=NO,SHOWALLPARAMS=NO
            ENDSCAN
            BASICSCAN/LINE,NUMBER OF HITS=18,SHOW HITS=NO,SHOWALLPARAMS=NO
            ENDSCAN
            BASICSCAN/LINE,NUMBER OF HITS=18,SHOW HITS=NO,SHOWALLPARAMS=NO
            ENDSCAN
            BASICSCAN/LINE,NUMBER OF HITS=18,SHOW HITS=NO,SHOWALLPARAMS=NO
            ENDSCAN
            BASICSCAN/LINE,NUMBER OF HITS=18,SHOW HITS=NO,SHOWALLPARAMS=NO
            ENDSCAN
            ENDMEAS/
A_FRONT    =FEAT/PLANE,CARTESIAN,OUTLINE,NO
            THEO/<0.49618,0,-4.044494>,<0,-1,0>
            ACTL/<0.49618,0,-4.044494>,<0,-1,0>
            CONSTR/PLANE,BF,SCN1,,
            OUTLIER_REMOVAL/OFF,3
            FILTER/OFF,WAVELENGTH=0
SCN4       =FEAT/SCAN,PATCH,NUMBER OF HITS=89
            ,SHOW HITS=NO,SHOWALLPARAMS=YES
            EXEC MODE=NORMAL, NOMS MODE=FIND NOMS,CLEARPLANE=NO,SINGLE POINT=NO,THICKNESS=0
            FINDNOMS=0.1,SELECTEDONLY=NO,USEBESTFIT=NO,PROBECOMP=YES,AVOIDANCE MOVE=YES,DISTANCE=0,CAD Compensation=NO
            DIR1=VARIABLE,MAX INCR=0.05,MIN INCR=0.01,MAX ANGLE=2,MIN ANGLE=1
            DIR2=LINE,INCR=0.2,AXIS=X
            HITTYPE=VECTOR
            INITVEC=0,1,0
            DIRVEC=1,0,0
            CUTVEC=0,0,-1
            ENDVEC=0,1,0
            PLANEVEC=-1,0,0
            POINT1=0.08,0.4,-3.64
            POINT2=0.92,0.4,-3.64
            POINT3=0.92,0.4,-4.44
            POINT4=0.08,0.4,-4.44
            MEAS/SCAN
            BASICSCAN/LINE,NUMBER OF HITS=17,SHOW HITS=NO,SHOWALLPARAMS=NO
            ENDSCAN
            BASICSCAN/LINE,NUMBER OF HITS=18,SHOW HITS=NO,SHOWALLPARAMS=NO
            ENDSCAN
            BASICSCAN/LINE,NUMBER OF HITS=18,SHOW HITS=NO,SHOWALLPARAMS=NO
            ENDSCAN
            BASICSCAN/LINE,NUMBER OF HITS=18,SHOW HITS=NO,SHOWALLPARAMS=NO
            ENDSCAN
            BASICSCAN/LINE,NUMBER OF HITS=18,SHOW HITS=NO,SHOWALLPARAMS=NO
            ENDSCAN
            ENDMEAS/
A_BACK     =FEAT/PLANE,CARTESIAN,OUTLINE,NO
            THEO/<0.49618,0.4,-4.044494>,<0,1,0>
            ACTL/<0.49618,0.4,-4.044494>,<0,1,0>
            CONSTR/PLANE,BF,SCN4,,
            OUTLIER_REMOVAL/OFF,3
            FILTER/OFF,WAVELENGTH=0
[COLOR=#008000]'FOUR ATTEMPTS TO CONSTRUCT[/COLOR]
WIDTH1     =FEAT/WIDTH,CARTESIAN,OUT,LEAST_SQR,NO
            THEO/<0.49618,0.2,-4.044494>,<0,1,0>,[COLOR=#ff0000]0.4[/COLOR]
            MEAS/<0.49618,0.2,-4.044494>,<0,1,0>,0.4
            CONSTR/WIDTH,[COLOR=#ff0000]BF,A_FRONT,A_BACK[/COLOR]
WIDTH2     =FEAT/WIDTH,CARTESIAN,OUT,LEAST_SQR,NO
            THEO/<0.49618,0.2,-4.044494>,<0,1,0>,[COLOR=#ff0000]0.55748[/COLOR]
            MEAS/<0.49618,0.2,-4.044494>,<0,1,0>,0.55748
            CONSTR/WIDTH,[COLOR=#ff0000]BFRE,A_FRONT,A_BACK[/COLOR]
WIDTH3     =FEAT/WIDTH,CARTESIAN,OUT,LEAST_SQR,NO
            THEO/<0.49618,0.2,-4.044494>,<0,1,0>,[COLOR=#ff0000]0.55748[/COLOR]
            MEAS/<0.49618,0.2,-4.044494>,<0,1,0>,0.55748
            CONSTR/WIDTH,[COLOR=#ff0000]BF,SCN1.HIT[1..SCN1.NUMHITS],SCN4.HIT[1..SCN4.NUMHITS][/COLOR]
WIDTH4     =FEAT/WIDTH,CARTESIAN,OUT,LEAST_SQR,NO
            THEO/<0.49618,0.2,-4.044494>,<0,1,0>,[COLOR=#ff0000]0.55748[/COLOR]
            MEAS/<0.49618,0.2,-4.044494>,<0,1,0>,0.55748
            CONSTR/WIDTH,[COLOR=#ff0000]BFRE,SCN1.HIT[1..SCN1.NUMHITS],SCN4.HIT[1..SCN4.NUMHITS][/COLOR]