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How to do cad to part alignment

I am trying to figure out just the start to finish method to align the cad model to the actual part itself in order for the cmm to know the true parts location. Can someone help break that down for me? Brand new to CMM and where I work just now started sending us cad files to work with, any help would be greatly greatly appreciated! Thanks!

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  • Well since you are brand new, maybe you wont get beat up too badly here... Have you taken the Demon 101 class? 

    I am not sure what you are trying to do though. 
    Are you trying to have the bad model in the proper orientation before starting your program?
    Have your machine automatically find the part and start measuring? 
    Do you need to know how to create a basic alignment?

  • I go for the 101 next week so I will probably get my answers there but we have a part I have to get laid out by this week so figured here might be my best bet between reaching out to support. I have the cad model loaded into pcdmis, but when I do the alignment for it to pull the cad and the true model together I think I must be doing it wrong because the true measurements don't line up with the model at all. And yes, the main goal is to get it to where when I click on a feature in the cad model, I can tell the cmm to go measure it and it know where the part is

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  • I go for the 101 next week so I will probably get my answers there but we have a part I have to get laid out by this week so figured here might be my best bet between reaching out to support. I have the cad model loaded into pcdmis, but when I do the alignment for it to pull the cad and the true model together I think I must be doing it wrong because the true measurements don't line up with the model at all. And yes, the main goal is to get it to where when I click on a feature in the cad model, I can tell the cmm to go measure it and it know where the part is

Children
  • So if you need to know where the part is, are you familiar with the readpoint function? It's the quickest way to help your machine find the part. Aside from maybe manual probing.

    Example here with the hexblock I put the readpoint at the center of a circle, and aligned to that readpoint position. Then it measures that circle, and you could align to that after. So you would execute the program from the readpoint with your probe manually placed there by you so that it can get it's position relative to the machine.

    To insert a readpoint just type read in the edit window. Of  course after this comes your main alignments to control your 6 Degrees of Freedom

    READ       =FEAT/POINT,CARTESIAN
                THEO/<0,0,0>,<0,0,1>
                ACTL/<0,0,0>,<0,0,1>
                READPOINT/
    READ_ALN   =ALIGNMENT/START,RECALL:STARTUP,LIST=YES
                  ALIGNMENT/TRANS,XAXIS,READ
                  ALIGNMENT/TRANS,YAXIS,READ
                  ALIGNMENT/TRANS,ZAXIS,READ
                ALIGNMENT/END
                MODE/DCC
                MOVE/CLEARPLANE
    CIR1       =FEAT/CONTACT/CIRCLE/DEFAULT,CARTESIAN,IN,LEAST_SQR
                THEO/<0,0,0>,<0,0,1>,2.5
                ACTL/<0,0,0>,<0,0,1>,2.5
                TARG/<0,0,0>,<0,0,1>
                START ANG=0,END ANG=360
                ANGLE VEC=<1,0,0>
                DIRECTION=CCW
                SHOW FEATURE PARAMETERS=NO
                SHOW CONTACT PARAMETERS=NO