Mating or Component Constraints if it is a regular shape with flat and circular surfaces. Reposition component is the catch all method for aligning by three points, two lines etc. If you component is at the right angular attitude but just out of position you can also use point to point repositioning if necessary.
First, since you're using NX 5, you should be using Assembly Constraints and NOT Mating Conditions. Generally speaking you should be able to use the 'default' Touch & Align methods and simply select edges or faces which are 'shared' between the part model and the mold cavity. Or as an alternative you could use Move Component and use the 'Reposition' method and use '3-point' methods picking common points between the part model and the mold cavity and once it's where you want it, go back the Assembly Constraints and use a 'Bond' constraint to keep the parts fixed relative to each other.
John R. Baker, P.E.
Product 'Evangelist'
NX Design
Siemens PLM Software Inc.
Cypress, CA
If your adding a revised part model that needs to be in the same place as the old one, try this:
-open original part/product model (make displayed part)
-add new part using absolute csys
-open too assembly
You will now have the new part in the correct position, as a sub-component to the existing part. To fix that,
-drag and drop the new part in the assy tree
I find this MUCH easier than adding the new part and trying to reposition it. Sometimes thats not possible with the 3d shape, lack of datums, and compound rotations required.
It will not be mated, but if you require that it could be mated after put into roughly the position you want.
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