Manual vs DCC alignment

I have taken the basic 1 week PCDMIS course from Hexagon.

Currently I have only modified part programs written by the programmer at our parent company location to run on our cmms.

I work with version 3.7 on cmm 2 and 2014 on cmm 3.

Cmm 1 has Measuremax which I am not sure how to program. This question is regarding cmm 2.

I think I may be a little confused about the purpose of running the dcc alignment after the manual alignment has run. I was under the impression that the manual alignment was to locate the part on the cmm, and the dcc alignment was the "fine tuning" and would adjust for very slight placement changes.

We have a fixture that is bolted to the fixture plate. The part is then mounted on the fixture and screwed into place using 1 screw. The part is secure, but due to different cavities with different die conditions may sit slightly different in the fixture each time. We are measuring the true position of a bore on the x minus side of the part with respect to the plane and bore at the x/y/z 0 position that is used to set the part alignment.

What we have noticed is that when we run the first part with the manual alignment the true position is within tolerance (.04mm). When we run a second part, if I mark all but choose not to mark the manual alignment portion, we see true position values between 0.1mm and 0.2mm.

If I then run the program on that same part again using the manual alignment without moving the part the true position values are again within tolerance. From what I read online yesterday after lots of digging it looks like the dcc alignment serves only to ensure the alignment features are properly probed and defined.

Is there any way around running the manual alignment each time? I don't mind if it's necessary for different cavities or runs, but for a 300pc cpk it's quite time consuming. Thanks in advance for any answers and/or suggestions. Oh, and I'm well aware of the noob hazing here. I have thick skin

.

Amber

Parents

acooke over 9 years ago

Thank you bigtall! I do see that I forgot to translate Z in my A4 alignment. Ugh, I'm starting to think it's more difficult to edit someone else's programs than to create your own. I will change that now and see if it has an effect on my issue. And, as requested, here is the code for the creation of datum D and the TP dimension code.

DAT_D_CYL  =FEAT/CYLINDER,RECT,IN,MAX_INSC
            THEO/6.141,-0.008,-0.02,-1,-0.0000985,-0.0002292,124.435,7.75
            ACTL/6.138,0.006,0.003,-1,0.000159,0.0002539,124.425,7.81
            CONSTR/CYLINDER,BF,D_BOT,D_MID,D_TOP,,
DIM LOC16= TRUE POSITION OF CYLINDER DAT_D_CYL  USE AXIS=START PT  REF LENGTH=0.000  UNITS=MM ,$
GRAPH=OFF  TEXT=OFF  MULT=10.00  OUTPUT=BOTH  DEV PERPEN CENTERLINE=OFF  DISPLAY=DIAMETER
AX    MEAS      NOMINAL     +TOL       -TOL       BONUS       DEV      OUTTOL   
Y       0.004      0.000                                       0.004           
Z       0.012      0.000                                       0.012           
DF                            0.025      0.025                -0.010      0.000 --#------
TP                   RFS      0.040                 0.000      0.026      0.000 -----#---
END OF DIMENSION LOC16

Reply

acooke over 9 years ago

DAT_D_CYL  =FEAT/CYLINDER,RECT,IN,MAX_INSC
            THEO/6.141,-0.008,-0.02,-1,-0.0000985,-0.0002292,124.435,7.75
            ACTL/6.138,0.006,0.003,-1,0.000159,0.0002539,124.425,7.81
            CONSTR/CYLINDER,BF,D_BOT,D_MID,D_TOP,,
DIM LOC16= TRUE POSITION OF CYLINDER DAT_D_CYL  USE AXIS=START PT  REF LENGTH=0.000  UNITS=MM ,$
GRAPH=OFF  TEXT=OFF  MULT=10.00  OUTPUT=BOTH  DEV PERPEN CENTERLINE=OFF  DISPLAY=DIAMETER
AX    MEAS      NOMINAL     +TOL       -TOL       BONUS       DEV      OUTTOL   
Y       0.004      0.000                                       0.004           
Z       0.012      0.000                                       0.012           
DF                            0.025      0.025                -0.010      0.000 --#------
TP                   RFS      0.040                 0.000      0.026      0.000 -----#---
END OF DIMENSION LOC16

Children

No Data