Cad vs touch programming

[[Ji...]]

When using Cad model for true position, the call out is true position .005 mmc AYmmcZmmc. The true position box will not give me the mmc for Y&Z. If we do it touch probe all the way the true position box lets me put mmc on Y&Z. Is there a way to get it to let me but mmc on Y&Z when doing it from the cad model? 

[[Ma...]]

Thats so confusing just to read it.

[[Ji...]]

I know it is confusing to read but I can not share the print due to corporate policy. I also do not have GD&T symbols.  So Datum Y has MMC and Datum Z has MMC. When doing it off the cad model it will not let me use MMC on Y or Z, If I manually program the same part I can use MMC, Why?

 

[[Ma...]]

I highly doubt that CAD has anything to do with that.

Check for evaluations ( tangential, gauss, ... ) and if it's same type of a feature.

[[Ri...]]

In some cases, a circle will not allow modifiers where a cylinder will.

[[Dr...]]

Hi Jimmy,

Could you describe the datum structure in terms of the pieces of geometry that make up A, Y, and Z? Understanding their orientation relative to each other may also be helpful. In a similar vein, are these pieces of geometry identical between the CAD-generated and manually probed method?

Let’s say that datum Y on the print is a shallow and very gently tapered bore, perhaps due to draft on an injected molded part. If you were to generate this feature via CAD, it would be detected as a cone, but if you were to probe it, the cone angle could be so slight that Calypso would generate the feature as a cylinder. This would cause a discrepancy on where material modifiers could be applied; MMB can be applied to a cylinder but not a cone. This is just one example, but knowing more about the geometry in play will help us narrow down specifics.

[[Ji...]]

Looks like you nailed it Drew. Where the CAD model created a circle on a cone is the issue. When you force it to cylinder or just scan a circle the MMC is able to be applied. I did not know that a cone would not allow MMC. So that keeps the streak alive of learning something new every day. Thanks Drew, Richard and Martin.