Constraining a bolt to a hole in a curved surface

[HIG2ALIFE]

I am having some trouble getting an assembly constraint to work out in NX 10. I am trying to get a fastener to be constrained to a hole in a curved surface. The bolt needs to be “centered” in the hole and the head of the bolt needs to remain tangent to the surface. I thought a combination of an “infer center/axis” touch/align on the cylindrical face of the bolt and the face of the hole with a touch constraint on the bolt head and curved surface would work, but that failed. What I resorted to was using a distance constraint on the axis of the bolt and the hole face making it the radius of the hole size and followed with an align constraint for the bolt head and the curved surface. That worked in about 50% of cases, but not in all cases. A concentric constraint doesn’t work because the hole is not a circle (due to being through a curved surface). Any thoughts on the right way to do this?

 

[JohnRBaker]

If the face of the 'hole' is cylindrical, there should be no problem aligning the axis of the bolt to the axis of the hole. Now as for constraining the head to the non-planar surface, I would try creating a Datum Plane normal to the hole axis and tangent to the surface and then use it to constrain the head of the bolt.

John R. Baker, P.E. (ret)
EX-Product 'Evangelist'
Irvine, CA
Siemens PLM:
UG/NX Museum:

The secret of life is not finding someone to live with
It's finding someone you can't live without

 

[Dave K]

As John said, the cylinders should align. For the bottom of the bolt head to the surface, try a touch between an edge on the bottom surface of the bolt, and the other surface.

-Dave

NX 11, Teamcenter 11