hexagon logo
Register Sign in
  • Replies 16 replies
  • Subscribers 227 subscribers
  • Views 346 views
  • Users 0 members are here
Options
Related

Auto-Cylinder vs Circles Constructing a Cylinder: For Perpendicularity

cmmGrum
Which is more accurate, the auto-cylinder to plane OR 3 auto-circles (constructing a best fit, least squared, cylinder) to plane.

Essentially they should have the same result, correct?

When I run it I have a 0.0009 difference between the results.

Which number should I trust?

(I am building off of an IGES file)

Looking at previous posts I made sure that I had it set to Perp to Datum
Parents
  • Note that the length of the cylinders will be different, and has an effect on the perpendicularity result. An auto cylinder gets the length from the CAD Surface, while the constructed (or measured) cylinder gets its length from the hits (ie. shorter than the auto cylinder). You can test by adding "projected zone" - (P) <length> - to your two perp dimensions to verify that they give the same result when applied to the same length (assuming the hits are the same).

    What version of PC-DMIS? I believe the length calculation for auto cylinder has changed during the life of PC-DMIS.
Reply
  • Note that the length of the cylinders will be different, and has an effect on the perpendicularity result. An auto cylinder gets the length from the CAD Surface, while the constructed (or measured) cylinder gets its length from the hits (ie. shorter than the auto cylinder). You can test by adding "projected zone" - (P) <length> - to your two perp dimensions to verify that they give the same result when applied to the same length (assuming the hits are the same).

    What version of PC-DMIS? I believe the length calculation for auto cylinder has changed during the life of PC-DMIS.
Children
© 2025 Hexagon AB and/or its subsidiaries. Privacy Policy | Cloud Services Agreement