×
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!
  • Students Click Here

*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.

Students Click Here

Jobs

Orientation question

Orientation question

Orientation question

(OP)
When I specify a Parallelism and/or Angularity is it necessary to specify a distance(parallelism) or an angle(angularity)?

In my case I am locating two parts to each other which will be welded in place.

In the case of the parallelism there are two surfaces which require to be parallel, but due to the complexity of the stack-up a dimension could not be given. I just want where ever they show up to be parallel.

For the Angularity there is one part with a large flat surface and a second part having several small surfaces all in the same plane at some angle from the large flat surface. I wish to specify a angularity which I understand will be a distance between two planes at an angle. The resultant angle will be different for every part produced, but all I want is the several small surfaces to be lined up with the main plane. I don't want to specify an angle.

Would someone know if this is possible?

 

RE: Orientation question

It would not be necessary to have a dimension for the parallelism, but it is necessary to have the locaton of the two surfaces to be defined in some way by the drawing. For the angularity, it is necessary to define the angle, if not by an angular dimension, then by other basic dimension back to the datum or datums you are referencing.

Peter Stockhausen
Senior Design Analyst (Checker)
Infotech Aerospace Services
www.infotechpr.net

RE: Orientation question

I would not use angularity if you do not care what the angle is.  I think you can use profile if you are using ANSI.  In an ISO environment you could use flatness with a common zone.

RE: Orientation question

ImnotfromMars,

   Your geometry ought to be defined by a bunch of basic dimensions.  When I do stuff like this, a few ± dimensions tend to wind up in there.  You need complete definition of your geometry, somehow.  If you are specifying angularity, an angle specification makes things easier for the inspector.

   Parallelism is independent from distance.

   Frequently, I apply parallel specifications onto sloppy ± dimensions.  A ± dimension or a profile tolerance controls parallelism, but sometimes, not enough.  The same goes for angularity.  Often, I have a composite FCF with a sloppy profile and an accurate angle.

   Just as a final note which may make things clearer, parallelism and angularity both control flatness.  The faces are not allowed to extend outside the tolerance zone.

   This all matters on weldments because the welders have to jig stuff.  It really helps to show them what your priorities are.

               JHG

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