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I need help with measuring TP

Good morning All,
I have a problem with TP. The position of the cylinders on the cone is at an angle. I need to understand why TP is out of tolerance if the diameter and position of these cylinders are correct.
Every tip is valuable.

-A- -> TOP PLN ( Z+ )
-B- ->ID CYL in center ( Z+ )
-C- -> cylinder on the side ( Y-)​

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  • Don't have all the print views I need, but here we go:

    The surface the hole is defined in is either also defined by basics, or there is a plane down from -A- where that Ø31.500 bolt circle is hitting, as it clearly isn't the intersection point with -A-.
    That point MUST exist, or you are under-defined on the drawing. If the face is defined by non-basics, I probably wouldn't argue it much with design, but you want to make manufacturing hold it REALLY close so you don't get a different answer than your customer during inspection and not be able to argue why you are right.

    Align ABC, which I presume puts you in the middle of a main bore, flat on -A- face, rotated so that -C- is pointing along an axis (I'm going to say it is pointing +X for the balance of this, but it could be -Y, you'd just have to adjust what you translate).
    Rotate 5° around Z, the basic rotation, bottom right.
    Translate down wherever the Ø31.500 is contacting surface (I hope that is a basic in a view you didn't provide, otherwise, you'll have to calculate it off the definition of that angled surface).
    Translate X 15.75, that is half the basic diameter.
    This puts your XYZ zero right at the mouth of where a perfect hole would be.
    Rotate around X around Y 120° (you could rotate Z around Y 30°, but if you do what is explicitly on the print, you don't have to think about what you did later during review).
    This has your alignment zeroed at the mouth of the hole AND rotated along the axis of the hole.

    Output in Legacy the Position of the hole.

    Tell it to give you BOTH start and end. You'll know where your cylinder is, if it is crooked, and why you have an issue.

    If you are programming off the CAD, and the alignment to the CAD isn't QUITE perfectly in agreement, the software might think the hole is somewhere other than it is supposed to be.

    you'll see this in the legacy command, as your axes should be both at 0. No numbers as a theo, you moved to the perfect (True) location. That is the concept with basics, you move to perfect and report Actual Position against the True Position. If your theo's have a number, something is wrong with your alignment, or something is wrong with your CAD, or, something is wrong with your alignment relating to the CAD.

    If the theos are zero, and the hole is off, you'll see if it is off at the top or bottom.

    Is there a burr.
    Did you go too far out the bottom of the hole and you are shanking.
    Is the probe angle off enough that you are shanking.
    Did you take three levels in that cylinder?
    Did the software solve the cylinder in the correct axis, or did it rotate it? (three levels will help prevent this, though it isn't 100%, especially if you shank or have other form error)

    Lots of ressons why, but start with looking at hard data you can conceptualize.

    I don't know anyone that thinks in polar coordinates.
Reply
  • Don't have all the print views I need, but here we go:

    The surface the hole is defined in is either also defined by basics, or there is a plane down from -A- where that Ø31.500 bolt circle is hitting, as it clearly isn't the intersection point with -A-.
    That point MUST exist, or you are under-defined on the drawing. If the face is defined by non-basics, I probably wouldn't argue it much with design, but you want to make manufacturing hold it REALLY close so you don't get a different answer than your customer during inspection and not be able to argue why you are right.

    Align ABC, which I presume puts you in the middle of a main bore, flat on -A- face, rotated so that -C- is pointing along an axis (I'm going to say it is pointing +X for the balance of this, but it could be -Y, you'd just have to adjust what you translate).
    Rotate 5° around Z, the basic rotation, bottom right.
    Translate down wherever the Ø31.500 is contacting surface (I hope that is a basic in a view you didn't provide, otherwise, you'll have to calculate it off the definition of that angled surface).
    Translate X 15.75, that is half the basic diameter.
    This puts your XYZ zero right at the mouth of where a perfect hole would be.
    Rotate around X around Y 120° (you could rotate Z around Y 30°, but if you do what is explicitly on the print, you don't have to think about what you did later during review).
    This has your alignment zeroed at the mouth of the hole AND rotated along the axis of the hole.

    Output in Legacy the Position of the hole.

    Tell it to give you BOTH start and end. You'll know where your cylinder is, if it is crooked, and why you have an issue.

    If you are programming off the CAD, and the alignment to the CAD isn't QUITE perfectly in agreement, the software might think the hole is somewhere other than it is supposed to be.

    you'll see this in the legacy command, as your axes should be both at 0. No numbers as a theo, you moved to the perfect (True) location. That is the concept with basics, you move to perfect and report Actual Position against the True Position. If your theo's have a number, something is wrong with your alignment, or something is wrong with your CAD, or, something is wrong with your alignment relating to the CAD.

    If the theos are zero, and the hole is off, you'll see if it is off at the top or bottom.

    Is there a burr.
    Did you go too far out the bottom of the hole and you are shanking.
    Is the probe angle off enough that you are shanking.
    Did you take three levels in that cylinder?
    Did the software solve the cylinder in the correct axis, or did it rotate it? (three levels will help prevent this, though it isn't 100%, especially if you shank or have other form error)

    Lots of ressons why, but start with looking at hard data you can conceptualize.

    I don't know anyone that thinks in polar coordinates.
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