Reporting Alignment Deviation

[zoolander303]

I tried searching for this with no luck, but in the software I use for our faro arm it will show me the actual alignment deviation from the part to the cad. When I run the cmm using PCDMIS I use a lot of iterative alignments for our parts, is their a way I can extract the deviation of the alignment and possibly even how many iterations it had to cycle through? I understand if I have a point target radius of 0.1 and a fixture tolerance of 0.1 then obviously everything is below that tolerance, but I just wanted to get the actual number.

Thank you.

[DAN_M]

*BUMP*

Anybody know the answer to this?

[neil.challinor]

This is something me and JEFMAN came up with. https://www.pcdmisforum.com/forum/pc...753#post477753

My bit is the first section that calculates the RMS (root mean squared) value. This is provided as an example routine - available from the discover tab of the home page in 2020 R1 or later.

Jefman used my example and then added the latter section to give the machine to part transformation.

[DAN_M]

Neil,

Thanks for taking the time to try and answer this for me. Unfortunately, as comfortable with the software as I am... that post is a bit over my head =/

Is there a more simplistic way to pull the calculated Target Point Radius out of an iterative alignment?

[Matthew D. Hoedeman]

Well, I would think that if you are talking about vector/surface points (AND SNAP=OFF must be used, and should be used), then you could just dimension them in the non-locating axis.

[DAN_M]

No my friend, am looking for something different. Sorry if I didn't properly articulate.

We specify to PCD that we want it to "FIND" the part within lets say 0.010" (target point radius).
Lets say the software does it's first iteration and actually finds the part within a target point radius of 0.002". 0.002 is less than 0.010 so its now happy & moves on.

How do I get PCD to report that 0.002 (or whatever number it was happy at and then accepted) to me?

[NinjaBadger]

Just as he says Dan.

If your A (Leveling) points are controlling Z, then report the X & Y for them.

[neil.challinor]

Like this. I added in the RMS calculation too since some people find it useful.

CIR1 =FEAT/CONTACT/CIRCLE/DEFAULT,CARTESIAN,IN,LEAST_SQR
THEO/<93.5,80.5,0>,<0,0,1>,15
ACTL/<93.5,80.52,0>,<0,0,1>,15
TARG/<93.5,80.52,0>,<0,0,1>
START ANG=0,END ANG=360
ANGLE VEC=<1,0,0>
DIRECTION=CCW
SHOW FEATURE PARAMETERS=NO
SHOW CONTACT PARAMETERS=NO
CIR2 =FEAT/CONTACT/CIRCLE/DEFAULT,CARTESIAN,IN,LEAST_SQR
THEO/<154.5,80.5,0>,<0,0,1>,15
ACTL/<154.51,80.5,0>,<0,0,1>,15
TARG/<154.51,80.5,0>,<0,0,1>
START ANG=0,END ANG=360
ANGLE VEC=<1,0,0>
DIRECTION=CCW
SHOW FEATURE PARAMETERS=NO
SHOW CONTACT PARAMETERS=NO
CIR3 =FEAT/CONTACT/CIRCLE/DEFAULT,CARTESIAN,IN,LEAST_SQR
THEO/<154.5,19.5,0>,<0,0,1>,15
ACTL/<154.5,19.53,0>,<0,0,1>,15
TARG/<154.5,19.53,0>,<0,0,1>
START ANG=0,END ANG=360
ANGLE VEC=<1,0,0>
DIRECTION=CCW
SHOW FEATURE PARAMETERS=NO
SHOW CONTACT PARAMETERS=NO
A1 =ALIGNMENT/START,RECALL:STARTUP,LIST=YES
ALIGNMENT/ITERATE
PNT TARGET RAD=5,START LABEL=,FIXTURE TOL=0.05,ERROR LABEL=
MEAS ALL FEAT=NO,LEVEL AXIS=ZAXIS,ROTATE AXIS=YAXIS,ORIGIN AXIS=XAXIS
LEVEL=CIR1,CIR2,CIR3,,
ROTATE=CIR1,CIR2,,
ORIGIN=CIR3,,
ALIGNMENT/END
DISPLAYPRECISION/6
DIM LOC1= LOCATION OF CIRCLE CIR1 UNITS=MM ,$
GRAPH=OFF TEXT=OFF MULT=10.00 OUTPUT=BOTH HALF ANGLE=NO
AX NOMINAL +TOL -TOL MEAS DEV OUTTOL MAX MIN
X 93.500000 0.050000 0.050000 93.480010 -0.019990 0.000000 100.980009 85.980010 --#------
Y 80.500000 0.050000 0.050000 80.500000 0.000000 0.000000 88.000000 73.000000 ----#----
Z 0.000000 0.050000 0.050000 0.000000 0.000000 0.000000 -2.000000 -2.000000 ----#----
D 15.000000 0.050000 0.050000 15.000000 0.000000 0.000000 0.000000 0.000000 ----#----
END OF DIMENSION LOC1
ASSIGN/DDSUMDEVSQRD=(LOC1.X.DEV^2+LOC1.Y.DEV^2+LOC1.Z.DEV ^2)
DIM LOC2= LOCATION OF CIRCLE CIR2 UNITS=MM ,$
GRAPH=OFF TEXT=OFF MULT=10.00 OUTPUT=BOTH HALF ANGLE=NO
AX NOMINAL +TOL -TOL MEAS DEV OUTTOL MAX MIN
X 154.500000 0.050000 0.050000 154.490013 -0.009987 0.000000 161.990013 146.990014 ---#-----
Y 80.500000 0.050000 0.050000 80.500000 0.000000 0.000000 88.000000 73.000000 ----#----
Z 0.000000 0.050000 0.050000 0.000000 0.000000 0.000000 -2.000000 -2.000000 ----#----
D 15.000000 0.050000 0.050000 15.000000 0.000000 0.000000 0.000000 0.000000 ----#----
END OF DIMENSION LOC2
ASSIGN/DDSUMDEVSQRD=DDSUMDEVSQRD+(LOC1.X.DEV^2+LOC1.Y.DEV ^2+LOC1.Z.DEV^2)
DIM LOC3= LOCATION OF CIRCLE CIR3 UNITS=MM ,$
GRAPH=OFF TEXT=OFF MULT=10.00 OUTPUT=BOTH HALF ANGLE=NO
AX NOMINAL +TOL -TOL MEAS DEV OUTTOL MAX MIN
X 154.500000 0.050000 0.050000 154.500000 0.000000 0.000000 162.000000 147.000000 ----#----
Y 19.500000 0.050000 0.050000 19.530000 0.030000 0.000000 27.030000 12.030000 -------#-
Z 0.000000 0.050000 0.050000 0.000000 0.000000 0.000000 -2.000000 -2.000000 ----#----
D 15.000000 0.050000 0.050000 15.000000 0.000000 0.000000 0.000000 0.000000 ----#----
END OF DIMENSION LOC3
ASSIGN/DDSUMDEVSQRD=DDSUMDEVSQRD+(LOC1.X.DEV^2+LOC1.Y.DEV ^2+LOC1.Z.DEV^2)
ASSIGN/ALNMT_RMS=SQRT((1/3)*DDSUMDEVSQRD)
COMMENT/REPT,
"Alignment RMS value = "+ALNMT_RMS