I just ran into this issue with a modified fixture (gage) that I needed to certify. Basically an existing fixture had a feature relocated. The feature is simply a holder for a digital indicator to measure a point on the part. I received the fixture and the new CAD,step, from our CAD guy. Three tooling balls on the fixture used for Iterative alignment with the cartesian coordinates stamped on the plate. I have PC-DMIS 2014. Using CAD and the tooling balls I create my iterative alignment manually and then in DCC mode. So far so good. All that is needed is to verify the new location which is simply an intersection point created from the plane of the surface the indicator mounts to and the inside cylinder in which the indicator resides. The program runs great but the resulting coordinates show the point to be a much as almost a millimeter off from nominal. First problem is that the outside gage company shows the point to be near nominal in all axis. We verified the tooling ball numbers as correct and then looked at the created point coordinates. Here is where we are perplexed. I do not have any CAD software available on the CMM computer so the CAD guy performed the function on Solidworks and we printed the coordinates. We then went to the CMM and I created a new program with the same CAD, created the point in the program, not actually performing the measurement, and the resulting numbers are similar to the results from the actual measurements. I have done this numerous times with other fixtures with no issues. We did the same with the tooling balls on CAD just to rule that out and his data and mine were identical. How can the intersection point, performed exactly the same manner, be different on the two computers? It can't be a hardware issue as I am not actually measuring the part. And if it is a software issue why is it only on this particular CAD? Would greatly appreciate some thoughts. Thank.
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