Center axis as a datum not repeat

Post some code?

I will post code once I get the morning fires put out.

What is the length of Datum B? How are you aligning? Are you Leveling to the Axis and Origin, what stops rotation? How far linearly is the measured feature to Datum B

Datum b is .50 imchs. My Original alignment was based off of the drawings a b and c datums. My feature control frame was using a b n c as a data reference feature. My future control frame was a true position to threecell at b. I created b as a datum off of the center of that cylinder. Engineering disagreed with the way I have that aligned. They want to see datum b as an alignment to itself. It is not leveled. It has nothing controlling rotation.

As long as datum -B- is measured as a 3d feature, you should be able to level to it as +Z and set both the X and Y origins to it. Since the measured feature will be coaxial to -B-, in theory, you do not need a rotational lock (X = 0; Y = 0). You will, however need a rotation for reference if you expect to be able to adjust based on the results.

Original code

BUB_37 =FEAT/CONTACT/CYLINDER/DEFAULT,CARTESIAN,IN,MAX_INSC
THEO/<-1.05,6.1515,-1.375>,<0,1,0>,1.437,-0.3069
ACTL/<-1.0509,6.1515,-1.3734>,<-0.0015014,0.999998,-0.0013551>,1.4376,-0.3069
TARG/<-1.05,6.1515,-1.375>,<0,1,0>
START ANG=0,END ANG=360
ANGLE VEC=<-1,0,0>
DIRECTION=CCW
SHOW FEATURE PARAMETERS=NO
SHOW CONTACT PARAMETERS=YES
NUMHITS=5,NUMLEVELS=3,DEPTH=0.1587,END OFFSET=0.0787,PITCH=0
SAMPLE METHOD=SAMPLE_HITS
SAMPLE HITS=0,SPACER=0
AVOIDANCE MOVE=BOTH,DISTANCE BEFORE=0.3937,DISTANCE AFTER=0.3937,DIRECTION=ALONG FEATURE VECTOR
FIND HOLE=DISABLED,ONERROR=NO,READ POS=NO
SHOW HITS=NO
BUB_39_DATUM_B=FEAT/CONTACT/CYLINDER/DEFAULT,CARTESIAN,IN,MAX_INSC
THEO/<-1.05,6.0663,-1.3726>,<0,1,0>,1.375,0.36
ACTL/<-1.0508,6.0663,-1.3734>,<0.0000676,1,0.0001943>,1.3754,0.36
TARG/<-1.05,6.0663,-1.3726>,<0,1,0>
START ANG=0,END ANG=360
ANGLE VEC=<-1,0,0>
DIRECTION=CCW
SHOW FEATURE PARAMETERS=NO
SHOW CONTACT PARAMETERS=YES
NUMHITS=3,NUMLEVELS=2,DEPTH=0.0587,END OFFSET=0.0787,PITCH=0
SAMPLE METHOD=SAMPLE_HITS
SAMPLE HITS=0,SPACER=0
AVOIDANCE MOVE=BOTH,DISTANCE BEFORE=0.3937,DISTANCE AFTER=0.3937,DIRECTION=ALONG FEATURE VECTOR
FIND HOLE=DISABLED,ONERROR=NO,READ POS=NO
SHOW HITS=NO
BUB_23 =FEAT/CONTACT/CYLINDER/DEFAULT,CARTESIAN,IN,MAX_INSC
THEO/<-2.03,6.5175,-1.3719>,<0,1,0>,0.1577,0.13
ACTL/<-2.0312,6.5175,-1.3702>,<0.007006,0.9999316,-0.0093632>,0.1578,0.13
TARG/<-2.03,6.5175,-1.3719>,<0,1,0>
START ANG=0,END ANG=360
ANGLE VEC=<-1,0,0>
DIRECTION=CCW
SHOW FEATURE PARAMETERS=NO
SHOW CONTACT PARAMETERS=YES
NUMHITS=3,NUMLEVELS=2,DEPTH=0.0587,END OFFSET=0.03,PITCH=0
SAMPLE METHOD=SAMPLE_HITS
SAMPLE HITS=0,SPACER=0
AVOIDANCE MOVE=BOTH,DISTANCE BEFORE=0.3937,DISTANCE AFTER=0.3937,DIRECTION=ALONG FEATURE VECTOR
FIND HOLE=DISABLED,ONERROR=NO,READ POS=NO
SHOW HITS=NO​

per engineering requests

BUB_37 =FEAT/CONTACT/CYLINDER/DEFAULT,CARTESIAN,IN,MAX_INSC
THEO/<-1.05,6.1515,-1.375>,<0,1,0>,1.437,-0.3069
ACTL/<-1.0509,6.1515,-1.3734>,<-0.0015014,0.999998,-0.0013551>,1.4376,-0.3069
TARG/<-1.05,6.1515,-1.375>,<0,1,0>
START ANG=0,END ANG=360
ANGLE VEC=<-1,0,0>
DIRECTION=CCW
SHOW FEATURE PARAMETERS=NO
SHOW CONTACT PARAMETERS=YES
NUMHITS=5,NUMLEVELS=3,DEPTH=0.1587,END OFFSET=0.0787,PITCH=0
SAMPLE METHOD=SAMPLE_HITS
SAMPLE HITS=0,SPACER=0
AVOIDANCE MOVE=BOTH,DISTANCE BEFORE=0.3937,DISTANCE AFTER=0.3937,DIRECTION=ALONG FEATURE VECTOR
FIND HOLE=DISABLED,ONERROR=NO,READ POS=NO
SHOW HITS=NO
BUB_39_DATUM_B=FEAT/CONTACT/CYLINDER/DEFAULT,CARTESIAN,IN,MAX_INSC
THEO/<-1.05,6.0663,-1.3726>,<0,1,0>,1.375,0.36
ACTL/<-1.0508,6.0663,-1.3734>,<0.0000676,1,0.0001943>,1.3754,0.36
TARG/<-1.05,6.0663,-1.3726>,<0,1,0>
START ANG=0,END ANG=360
ANGLE VEC=<-1,0,0>
DIRECTION=CCW
SHOW FEATURE PARAMETERS=NO
SHOW CONTACT PARAMETERS=YES
NUMHITS=3,NUMLEVELS=2,DEPTH=0.0587,END OFFSET=0.0787,PITCH=0
SAMPLE METHOD=SAMPLE_HITS
SAMPLE HITS=0,SPACER=0
AVOIDANCE MOVE=BOTH,DISTANCE BEFORE=0.3937,DISTANCE AFTER=0.3937,DIRECTION=ALONG FEATURE VECTOR
FIND HOLE=DISABLED,ONERROR=NO,READ POS=NO
SHOW HITS=NO
A1 =ALIGNMENT/START,RECALLCC_ALIG,LIST=YES
ALIGNMENT/LEVEL,YPLUS,BUB_39_DATUM_B
ALIGNMENT/TRANS,ZAXIS,BUB_39_DATUM_B
ALIGNMENT/TRANS,XAXIS,BUB_39_DATUM_B
ALIGNMENT/END
BUB_23 =FEAT/CONTACT/CYLINDER/DEFAULT,CARTESIAN,IN,MAX_INSC
THEO/<-0.98,6.5175,0.0007>,<0,1,0>,0.1577,0.13
ACTL/<-0.9804,6.5171,0.0031>,<0.0069385,0.9999303,-0.0095575>,0.1578,0.13
TARG/<-0.98,6.5175,0.0007>,<0,1,0>
START ANG=0,END ANG=360
ANGLE VEC=<-1,0,0>
DIRECTION=CCW
SHOW FEATURE PARAMETERS=NO
SHOW CONTACT PARAMETERS=YES
NUMHITS=3,NUMLEVELS=2,DEPTH=0.0587,END OFFSET=0.03,PITCH=0
SAMPLE METHOD=SAMPLE_HITS
SAMPLE HITS=0,SPACER=0
AVOIDANCE MOVE=BOTH,DISTANCE BEFORE=0.3937,DISTANCE AFTER=0.3937,DIRECTION=ALONG FEATURE VECTOR
FIND HOLE=DISABLED,ONERROR=NO,READ POS=NO
SHOW HITS=NO​

drawing

​

That's fine, but your X has a non-zero value. Without a rotational datum, you'll get a different measurement every time you stage it.

I agree and this is exactly what is happening.