using cad model as reference

[Homer-Jay]

i have a question about probing points onto a casting using the cad model reference as the compensation direction for your points. ie.. you would be probing points, and instead of choosing compensate to plane, or use compensation point in the sub menu, you choose compensate to reference object. my question is this. if i have a casting with a surface that is drafted, or uneven, how does the program know which way to compensate for the ball if in one spot your refence object is larger than the part being inspected, and in another spot on the same face, the reference object is smaller than the casting.   maybe it was a low spot caused by over-grinding or something.

[jrayself]

It compensates along the normal vector of the CAD surface.

[Homer-Jay]

i finally made it to the training, and while i was there downloaded the latest patch. the 11.0.28 version doesn't seem to give you the option to compensate to the reference object like the previous version did. but it did introduce the ability to compensate along a standard axis, which is now (in my opinion) the best way to compensate for the tip when probing points to use for linear dimmensionig. What i do is probe enough features to build an accurate coordinate system, using the "probe orientation" compensation mode to probe my features, then switch to the "compensation point" compensation mode to probe points for linear dimmensions. i was previously using the compensation point method to lay in my points for linear dimmensioning. this is where you pull the probe away from the surface to instruct the machine to compensate in the opposite direction. this was giving me cosine error though. because it is impossible to pull it away exactly normal to the surface, unless you built some kind of jig. but using the option to compensate along the standard axis i am able to dimmension a gage block to within 0.0001 accuracy. this is of course with the work piece positioned in the optimal location in relation to the base of the arm.