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Showing posts from April, 2018

CMM Fixturing Measurement Techniques

Does CMM correct a bad fixturing of a workpiece? Does CMM correct the impact that a bad fixturing has  on GD&T's, lengths, diameters and angles ? I think, the part fixturing and part alignment into the fixture is the main factor in CMM incorrect measurements. If we define the part fixturing and alignment incorrectly as a concept the CMM will be used incorrectly.  If the CMM result of a trueposition of a feature to datum -A- is out of the tolerance can the CMM correct the true position if it the datum A is measured as a cylinder and the part is 3 degrees skewed from being parallel to the CMM axis. I never have assumed that the CMM corrects the errors of fixturing, and the part can be measured without a precise fixturing/alignment. First question I will ask is what’s our benefit if the CMM does that? We do not need a precise fixturing-alignment of the part into a fixture and consequently we save some time/cost on this. Practically, how it is going to work when we mea