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i need help with a big part with iterative

pcdmisstudent
Hey guys
so i have this big part, that the datums are defined by 3 datums points (three holes with sample hits that i did iterative with). I then constructed three theorietical planes (alignment planes) and defined those as ABC. Then i measured all the different features on the parted and called them out using FCF position.
the program works well, but some of my results gets weirdly high.
Ill upload pics with the datum targets (see black circles)
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  • I dont trust my alignment.
    Most numbers are ok, but they r sketchy
    Like these two threads for example, one of them are measured 0.216mm the other 0.517mm
    They are done by the same tool it shouldnt differente that much between them.
    i dont like iterative...cos i dont understand it

    Check out this thread I made ages ago.

    I think the formatting is off, but if you can follow it it might make clearer what an iterative alignment does.

    Basically your creating an offset plane from your level features and leveling to that (offset in the axis they're controlling). Then an offset line from your rotation features, and rotating to that. You then create an offset point from you origin feature, and origin on that.

    The iterative part, is that after aligning, the position of each point is evaluated against the point target radius, and if it's out it's remeasured, and the process repeated until it's in tolerance. For features with a fixed centre (such as spheres or circles with sample hits ) this typically isn't necessary so one DCC measure will do.

    https://www.pcdmisforum.com/forum/pc-dmis-enterprise-metrology-software/pc-dmis-for-cmms/388452-long-hand-iterative-alignment-without-using-iterative-alignment-command
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  • I dont trust my alignment.
    Most numbers are ok, but they r sketchy
    Like these two threads for example, one of them are measured 0.216mm the other 0.517mm
    They are done by the same tool it shouldnt differente that much between them.
    i dont like iterative...cos i dont understand it

    Check out this thread I made ages ago.

    I think the formatting is off, but if you can follow it it might make clearer what an iterative alignment does.

    Basically your creating an offset plane from your level features and leveling to that (offset in the axis they're controlling). Then an offset line from your rotation features, and rotating to that. You then create an offset point from you origin feature, and origin on that.

    The iterative part, is that after aligning, the position of each point is evaluated against the point target radius, and if it's out it's remeasured, and the process repeated until it's in tolerance. For features with a fixed centre (such as spheres or circles with sample hits ) this typically isn't necessary so one DCC measure will do.

    https://www.pcdmisforum.com/forum/pc-dmis-enterprise-metrology-software/pc-dmis-for-cmms/388452-long-hand-iterative-alignment-without-using-iterative-alignment-command
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