INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Jobs

Fig 6-19 - ASME 1994 and orientation (profile versus position)

Fig 6-19 - ASME 1994 and orientation (profile versus position)

(OP)
Does the profile in Fig 6-19 / 1994 (ASME) controls orientation or this job is reserved for the position?

RE: Fig 6-19 - ASME 1994 and orientation (profile versus position)

aniiben,

The outline cannot be rotated sufficiently to extend through the LMC and MMC outlines. That is an orientation control.

--
JHG

RE: Fig 6-19 - ASME 1994 and orientation (profile versus position)

Profile tolerance controls the perpendicularity of the walls to A. I might agree with drawoh that the boundary created by the position tolerance will probably restrict the orientation to B and C before the profile tolerance IF the feature is at it's MMC size; however, at LMC it will be a close call to figure out which boundary restricts orientation to B and C first (inner or outer.

John Acosta, GDTP Senior Level
Manufacturing Engineering Tech

RE: Fig 6-19 - ASME 1994 and orientation (profile versus position)

Does anyone know/guess why in 2009 revision datum feature A has been removed from the profile? I don't.
Or I am not sure why.

RE: Fig 6-19 - ASME 1994 and orientation (profile versus position)

Probably because the inner boundary is already oriented to A via the position callout. The walls can be in any location and orientation within the profile tolerance zone and the inner boundary cannot be violated. I don't think this is an incorrect callout. It's definitely different from the 1994 figure though.

John Acosta, GDTP Senior Level
Manufacturing Engineering Tech

RE: Fig 6-19 - ASME 1994 and orientation (profile versus position)

aniiben,

I am curious. What lead you to ask this question?

pylfrm

RE: Fig 6-19 - ASME 1994 and orientation (profile versus position)

2

Quote (pylfrm)

I am curious. What lead you to ask this question?

Maybe it is the wording of associated paragraph in the standard (6.5.5.1):
"In this example [fig. 6-19], the basic dimensions and the profile tolerance establish a tolerance zone to control the shape and size of the feature."

Because of presence of A in the profile callout, that statement seems incomplete at best.

By removing A from the profile callout in the 2009 standard, this problem was solved.

RE: Fig 6-19 - ASME 1994 and orientation (profile versus position)

However, pmarc, having datum A in the profile tolerance at least allowed the two geometric tolerances to be measured on the same primary plane. Perhaps that made it easer for gaging; just drop the part onto a table, and it would be a simple matter to engage B and C when needed for the position measurement.
But I agree that the actual relationship to datum A is controlled by position, and you make a good point about the picture now matching the text description.

John-Paul Belanger
Certified Sr. GD&T Professional
Geometric Learning Systems

RE: Fig 6-19 - ASME 1994 and orientation (profile versus position)

greenimi

With the presence of A in the profile callout, it will not only control the shape and size geometric characteristics but also the orientation, the table below is a good reference. (quote from Alex's Advanced Concepts of GD&T page 22-9)

Thanks pmarc lead me to look at this table, you catched the point shape and size.

RE: Fig 6-19 - ASME 1994 and orientation (profile versus position)

Since some answers were addressed directly to me (even I am not the one who asked the original question) I would say that having datum feature A in the profile is a mistake in the standard (rectified by the 2009 revision). In the court of law only the text (and yes, not the pictures) counts and considered in a legal argument. Pictures only help visualize the concept.
That is my opinion based on pmarc's referenced paragraph from 1994.

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources


Close Box

Join Eng-Tips® Today!

Join your peers on the Internet's largest technical engineering professional community.
It's easy to join and it's free.

Here's Why Members Love Eng-Tips Forums:

Register now while it's still free!

Already a member? Close this window and log in.

Join Us             Close