CAD - coordinate system 90 degree flip

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  • CAD - coordinate system 90 degree flip

    Hopefully this is a simple issue.

    How do I flip the model's coordinate system by only 90 degrees?

    I've come across a solid model where I need to flip an axis 90 degrees so it's coordinate system will match my CMM coordinate system when I IMPORT my CAD model.

    In the solid model file, I choose "Insert / Reference Geometry / Coordinate system. Here I am able to choose an axis then hit an icon to flip it 180 degrees. I don't know how to flip it just 90 degrees.

    FYI, after I flip the model's coordinate system, I save it as an IGES file and IMPORT this new IGES file into my CMM Program.

    Thank you in advance.
    Your life is happening, Participate!

  • #2
    The following may help you

    Originally posted by Matthew D. Hoedeman View Post
    Alignments:

    First of all, to do ANY alignment, 3-2-1 or iterative, you MUST have XYZ values for whatever you use for the alignment.

    Step #1
    Do this no matter WHAT type of alignment you are going to do.
    1) Place the part on the table the way it will sit for your inspection
    2) Import your model data BEFORE you do any measuring
    3) Using the CTRL-F3 option (3-D rotate), rotate the cad data until it matches the way the part sits on the machine, remembering that as you look at the screen you are looking DOWN on the machine
    4) Once you have the cad data rotate (you are actually ONLY rotating the VIEW of the cad data), use F5 to open the setup options.
    5) Go to the Part/Machine tab and while looking at the 3-D rotate cube, set your CAD to MACHINE axis
    6) Click OK
    7) Set your workplane to the ‘top’ of the cube (if the top, facing YOU face of the cube is X-, use the X- workplane)

    You are now ready to do an alignment.

    Iterative alignment
    1) You need to know WHAT the datums are that you have to use for alignment. Use CTRL-F to open the AUTO FEATURES window
    2) Select the type of feature you are going to use (vector, surface, circle, etc.) and pick that feature from the model
    3) Create the feature, BUT DO NOT MEASURE IT!
    4) Continue until you have all the features you need for your alignment, remember, ALL circular feature types NEED a minimum of 3 surface sample hits (circles, cylinders, cones, slots)
    5) Go into the alignment and then into ITERATIVE alignment
    6) Select the (minimum of) 3 ‘level’ features
    7) Select the (minimum of) 2 ‘rotate’ features
    8) Select the (minimum of) 1 ‘origin’ feature
    9) Set the tolerance to high values, I use 10mm radius and 1mm fixture
    10) OK out of the iterative window and the alignment window
    11) You are now aligned
    12) Turn on DCC mode and repeat steps 1 to 10, making the program executable, meaning it will run without crashing. HOWEVER, for the tolerances, at this point, I use 0.5 for radius and 0.05 for fixture. ALSO, mark the MEASURE ALL ALWAYS box in the iterative window
    13) Now, program the checks of the part

    3-2-1 alignment (mostly for holding fixtures)
    This is a very easy alignment, however, you will have to think back to 2nd or 3rd grade when they taught you to use a number line (you’ll see)
    1) All the alignment features on the fixture SHOULD have XYZ values stamped on them. For this example, I will use a plane, and 2 lines (top corner of the fixture base)
    2) Measure the plane, making sure that all the touches are EXACTLY where you want them to be
    3) Measure a line (the longer edge of the base) for the ROTATE, making sure of the DIRECTION of the line
    4) Measure the second edge of the base (direction makes no difference)
    5) Construct a point at the intersection of the 2 lines
    6) Now, you need to know exactly WHAT each of those features represent. We will say that the PLANE is for the X+ axis, the rotate line points in the Y+ direction (first to last point taken on the line) and we need to know they XYZ value for that corner of the fixture base
    7) Open the alignment window
    8) Level X+ to the plane
    9) Rotate Y+ ABOUT the X+ axis to the rotate line
    10) Set the X origin to the plane
    11) Set the Y axis to the corner point
    12) Set the Z axis to the corner point
    13) Now, it is time to offset the origins. This is where the number line comes into play
    IF the X value for the top of the base is equal to 1250mm, then you need to offset the X origin –1250mm. What you are doing is telling Pcdmis the direction (in this case -) and the amount to move the ZERO point, which right now is located at the corner of the base. This will make the base equal to X1250.

    Do this for each of the axis, remembering that you are telling it the DIRECTION and AMOUNT to move the origin AWAY from where you have the origin set to.

    So, for the corner values of the fixture at X1250, Y-250 and Z2321, your offsets will be X-1250, Y250 and Z-2321

    14) Click on CAD=PART
    15) Close the alignment window.
    You model should now be ‘floating’ in space about the alignment features just like it does on the fixture.
    16) Go into DCC mode and program the alignment as an executable program (one that will run without crashing). The reason for this is simple, the machine will give better, more accurate touches than you, the operator can. The speed of the touch CAN and DOES have a big impact on the final results Pcdmis see for the touch. Faster or slower can change the comp of the point, so use DCC. Not only that, but if you have to re-home the machine or re-calibrate the probes (for whatever reason), you need ONLY run the DCC portion of the alignment, the manual can be left un-done, as long as the fixture has not been moved on the table
    16) Program and check the part.

    I use non-iterative alignments almost exclusively and I never have any problems or issues with them. I also keep the alignment as a separate program, saving the alignment to an external file, then recalling that external file in my check programs. In this way, I can have multiple programs to check various portions/operations of the part WITHOUT the need to align multiple times. Sure, you can cram it all into one program, but that will slow Pcdmis down. Also, by using separate check programs, I can send the various data sets to different Datapage files.
    Lately, it occurs to me
    What a long, strange trip it's been.

    2017 R1 (Offline programming)

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    • #3
      Originally posted by Big Red View Post
      Hopefully this is a simple issue.

      How do I flip the model's coordinate system by only 90 degrees?

      I've come across a solid model where I need to flip an axis 90 degrees so it's coordinate system will match my CMM coordinate system when I IMPORT my CAD model.

      In the solid model file, I choose "Insert / Reference Geometry / Coordinate system. Here I am able to choose an axis then hit an icon to flip it 180 degrees. I don't know how to flip it just 90 degrees.

      FYI, after I flip the model's coordinate system, I save it as an IGES file and IMPORT this new IGES file into my CMM Program.

      Thank you in advance.
      PC DMIS does not provide a method of rotating or translating model files. My 'other' DMIS progam allows this and it was a shock for me to work with PC DMIS.

      Now the good news. You do not need to. You just need to pick some points on the model in Manual Mode and align to them. When you run this on your CMM it will rotate as you want.

      Here are a couple detailed ways:

      You can actually rotate the model with as little as one point. Pick a point on the model in the Axis you WANT Z to be in. Measure it as a POINT. Level to the POINT in Z Axis. When you run the program measure the point directly in the Z AXIS and after your alignment command is encountered the model will be rotated to the orientation on the table.

      I used the point scenario as an illustration of the concept. In practice you will want to grab a 3-2-1 alignment in manual. Plane Line Point etc. The only key here is that you have to pick the points on the model and let them be defined by the model. Do not worry that they are not in the same coordinate system as your CMM. Then, when you measure them on the CMM in their actual vectors the model will 'snap' to your Table Coordinate System.

      Works easier than you might think.

      HTH,
      Bill
      Bill Jarrells
      A lie can travel half way around the world while the truth is putting on its shoes. - Mark Twain

      Comment


      • #4
        Originally posted by Wingman View Post
        PC DMIS does not provide a method of rotating or translating model files. My 'other' DMIS progam allows this and it was a shock for me to work with PC DMIS.
        Well... actually, I think this is possible, just not in versions prior to 4.0.

        Big Red, I'm not exactly sure if this is what you're looking for, but in 4.0 and later you can do Operation | Graphics Display Window | Transform. This provides a way for you to translate, scale, and rotate your part model to a new coordinate system. Access that dialog and press F1 to view the help file's topic on this functionality.
        Jared Hess - Techwriter @ WAI
        [View 2008 Reporting Tutorials Here]

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        • #5
          Originally posted by JaredHess View Post
          Well... actually, I think this is possible, just not in versions prior to 4.0.

          Big Red, I'm not exactly sure if this is what you're looking for, but in 4.0 and later you can do Operation | Graphics Display Window | Transform. This provides a way for you to translate, scale, and rotate your part model to a new coordinate system. Access that dialog and press F1 to view the help file's topic on this functionality.
          I don't mean to hijack this thread, but I needed to do this myself and it works. However, while programming offline, my probes are being animated as coming from Zminus. I need them to come from Zplus

          ?
          -Bill

          PC-DMIS 4.2 MR1 - Global Image 7107 - PH10MQ - SP600M

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          • #6
            You need to transform/rotate 180 degrees around X or Y.
            Lately, it occurs to me
            What a long, strange trip it's been.

            2017 R1 (Offline programming)

            Comment


            • #7
              Humm, I did. It flips my cad back around, but not the probes. What am I doing wrong?

              Eh, never mind. I'm going to have it done in mastercam.
              Last edited by PowerJunkie; 02-13-2009, 01:40 PM.
              -Bill

              PC-DMIS 4.2 MR1 - Global Image 7107 - PH10MQ - SP600M

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