XXT Head vs Vast Head

[[St...]]

Comparing results from a XXT Head to results from a Vast Head on a Prismo Navigator.

 

Not sure what type of CMM that the supplier is using but do know that they are using an XXT Head, we are using a Prismo Navigator with a VAST Head. So, the Quality Engineer is comparing results of five parts that the supplier has measured to the same five parts that we have measured. Supplier is using a XXT Head, and we are using a VAST Gold Head. Even though all the measurements from both of us are within tolerance. They are expecting only a 10% deviation in the measurements. Is this a reasonable expectation given the different CMM's and Heads? Plus not knowing how many points, speed or if they are using any filters. 

[[Ri...]]

It is reasonable, but, filters and outliers, scanning speeds will factor into this.

[[Ow...]]

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As well as how they may hold the part while it is being inspected, the alignments, temperature, part deformation over time, probe lengths and ruby size .

Quite frankly, there are a lot of variables that affect the results.

I've acquired a few grey hairs over the years working with other companies CMM report results 🙂 

[[Ke...]]

Tyically, when there are discrepancies between results and the supplier is using a Zeiss CMM, I will request a copy of their Measurement Plan, so that I can evaluate their settings and evaluation methods.

[[Ri...]]

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And that's why hair color was invented. 😁

[[Ra...]]

10% deviation is probably not possible unless you have the exact same program, stylus systems, holding fixture, etc. Depending on the tolerances, you might even need the exact same lab environment.

[[Wo...]]

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I think it depends on the tolerance. Does 10% equal 0.001" or 0.0001" ? In situations like this we've usually had our customer share the CMM plan with us, and then we've tried to match the probes as close as possible. This way at least all the evaluation settings were the same.