Concentricity

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JMDurex16
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Concentricity

Post by JMDurex16 » Fri Oct 16, 2020 8:32 am

Looking for some quick help on reporting concentricity.


Is it best to use circle to circle or cylinder to cylinder?

When reporting concentricity between circles, to me, it shouldn't matter which i use as the "datum" but when I report them I'm getting to very different answers depending on which circle I use as the datum. Does this happen to anyone else? Is it something I'm doing or just a software flaw? When we physically indicate the part on the machine, we are getting less than .002, but CMM is showing me .010+.

Any help would be greatly appreciated, thanks!

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CrashN8
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Re: Concentricity

Post by CrashN8 » Fri Oct 16, 2020 2:28 pm

This is due to Tilt and (maybe form error) of each circle. Think of the circles as Cylinder... then consider the c-line of one vs. the other... I think there are previous discussions here on forum about this topic.

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