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True position of sphere with lmc bonus tolerance issue

I Have attached an example report showing that the bonus tolerance given when using the DEFAULT feature size on a SPHERICAL TRUE POSITION with LMC is incorrect.
As you can see the other 3 bonuses given are correct when using LSQ feature size or MMC.
It seems to be only when using LMC with DEFAULT feature size that there is an error.
Can anyone please explain this?
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  • MMC/LMC shouldn't change the size though should it? only the amount of bonus tolerance?


    That's true for LSQ because least squares only has one size (the LSQ average of all the hits). When using DEFAULT math, you have both mating envelope and local size. Mating envelope is based on the Taylor principle and is either internal or external to material. For the LSQ case we are currently reporting the MMC mating envelope instead of the LMC mating envelope.

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  • MMC/LMC shouldn't change the size though should it? only the amount of bonus tolerance?


    That's true for LSQ because least squares only has one size (the LSQ average of all the hits). When using DEFAULT math, you have both mating envelope and local size. Mating envelope is based on the Taylor principle and is either internal or external to material. For the LSQ case we are currently reporting the MMC mating envelope instead of the LMC mating envelope.

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