Model Alignment Question

[[Da...]]

I have a part that has a model, but I needed to align off a fixture of sorts. They are using a pin to clock the part. I trapped the pin between two parallels and touched off the outside of one of the parallels. I manually touched off the part and made an alignment. Then I brought the model into the alignment and Transformed the model into the alignment. It seems to have worked but, I get some tiny differences between the model and the alignment. Have any of you used this method? I think the differences are due to slight flatness or perpendicularity differences between the model and the actual part, It's good enough for what I'm doing , but, can it be refined?

Oh, Happy Friday !

[[Ia...]]

I might not fully grasp your issue, but if I only have the part model, and want to do a fixture alignment, I still create the features off the part CAD for the fixture alignment. I grab the mating face of the part, and then just invert the points and move them in space to fit the fixture. Same with pins, I'll grab the nominals for the hole or slot, and then invert the points. Should be nominally perfect.

[[No...]]

I agree with Ian. Avoid mixing data touched on the real part with data taken from CAD whenever possible. It's a PITA to get rid of those tiny deviations afterwards.
By the way, to you can model simple fixture parts in Calypso by adding planes and cylinders to the CAD model. It's under CAD / Modify CAD Entities --> Create Geometry.