hexagon logo
Register Sign in
  • Replies 4 replies
  • Subscribers 17 subscribers
  • Views 59 views
  • Users 0 members are here
Options
Related

Run out question

Michael R
Good morning all, i have a gd&t question i"m not sure about.
Does circularity come into play when both the feature and the datum are running out together, each in the same direction?
The o-ring groove and datum are both elliptical by .005 but measure within .0003 to each other. Well within the .002 called out.
I feel the parts meet the runout requirement but my coworker's opinion is the .005 measured on circularity puts them out.
Thanks in advance.
  • Runout is relative to the axial center of the datum. Not the outer face. The runout dimension is a nonconformance.
    A datum is not per print either, if it has 0.005" roundness on a 0.003" tolerance. Form is controlled by size if not controlled by any other call-outs.
  • in reply to louisd
    however, if both diameters show they are concentric to each other, you should consider the root cause to be handling/damage, and not manufacturing-related causes.
  • Yes Louisd both diameters are concentric, they were turned together in the same setup and the part went out of round .005 when taken out of the lathe possibly from stress relief.
    Since the print did not have a cylindrical or roundness call out and both diameters ran together from center I thought the part was in tolerance, but I stand corrected that roundness is a requirement of run out.
    Thank you for your reply.
  • As said, the form (ie. roundness) is controlled by Rule 1 of Y14.5 which states that "the limits of size of a feature prescribe the extent within which variations of geometric form, as well as size are allowed." The 0.005" roundness would suggest that somewhere on the diameter, 2 opposing points violate the diametrical tolerance zone. This is independent of the runout tolerance zone.
    HTH
© 2024 Hexagon AB and/or its subsidiaries. Privacy Policy | Cloud Services Agreement