×
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

Combining Composite and Bidirectional call outs

Combining Composite and Bidirectional call outs

Combining Composite and Bidirectional call outs

(OP)
Is it ok to combine a Composite hole location with a Bidirectional call out? I want to allow the PLTZF to have a relatively large X movement, with a smaller Y movement, while at the same time I would like to limit the FRTZH and have it be a diametric control. I could find no examples in Y14.5, nor anything saying I could or could not combine the 2 methods. If it would be cleaner to remove the diameter off the FRTZH and have it be a square zone, I could do that also.

I have included an attachment, because I am sure I have not explained what I am trying to do in a clear way, and a picture is worth a thousand words.
http://files.engineering.com/getfile.aspx?folder=babed142-e632-42e5-b7a0-7b2ef3701245&file=Composite-Bidirectional.JPG

Thank you.

RE: Combining Composite and Bidirectional call outs

I am uncomfortable with having two composites applied to the same pattern.

"For every expert there is an equal and opposite expert"
Arthur C. Clarke Profiles of the future

RE: Combining Composite and Bidirectional call outs

(OP)
CheckerHater,

I am uncomfortable with it also, but it is the closest thing I can think of to achieve the end requirements. Any ideas on a cleaner method would be greatly appreciated.

RE: Combining Composite and Bidirectional call outs

By definition Composite is single control applied to pattern.

Could it be multiple segment:

.100|A|B|
.025|A|C|
.010|A|
?

(Just thinking out loud)

"For every expert there is an equal and opposite expert"
Arthur C. Clarke Profiles of the future

RE: Combining Composite and Bidirectional call outs

marshell,
First, you may want to take a look at fig. 5-41 in Y14.5M-1994 or fig. 7-28 in Y14.5-2009. These figures show proper way of specifying bidirectional position tolerance.

Then, in order to define what you want, just attach additional position feature control frame wrt A to a size requirement.

Side note: It is a FRTZF, not FRTZH winky smile

RE: Combining Composite and Bidirectional call outs

Yes, that is what I meant.

RE: Combining Composite and Bidirectional call outs

Is this composite (the position shown) or multi-single segments?

RE: Combining Composite and Bidirectional call outs

It would be similar to multi-single segments requirement.
In composite position tolerancing, FRTZF can float around inside boundary of PLTZF, being orientation controlled by datum referenced in the lower segment.
In multi-single segments tolerancing, FRTZF cannot float freely inside PLTZF since datum referenced in the lower segment also constrains the location of tolerance zone.

In the second attached drawing,location of Ø.010 tolerance zone, though Datum B and C are not referenced, would be fixed in its true position.

RE: Combining Composite and Bidirectional call outs

Are we talking about Y14.5 - 1994 or 2009 ?

RE: Combining Composite and Bidirectional call outs

I wrote based on 1994.
Looking over 2009 chapter 7.5.2, it doesn't look quite different, except that the terms FRTZF and PLTZF are no longer applicable to multi-single segments.
As I understood, main difference between composite and multi-single segments is whether the lower segments constrain the location of tolerance zone or not, in other words, basic dimensions from referenced datums are effective or not.

RE: Combining Composite and Bidirectional call outs

Okay. Thank you Woosang.

RE: Combining Composite and Bidirectional call outs

So , I guess the OP question should be “ multi-single segments” instead of “composite, right?
I don’t see where composite is shown in the pictures attached. Am I missing something?

RE: Combining Composite and Bidirectional call outs

(OP)
Greenmini,

My intent is to have the call out along the lines of a composite. I want to allow the hole pattern to float in a large, rectangular zone, but I want to ensure the hole to hole location of the pattern stays tight in a normal circular zone. Basically I am mounting something on a rail, and I want to allow a large float of a tight pattern along that rail. Allowing more tolerance along its length, while limiting its side to side movement on the rail.

Thank you.

RE: Combining Composite and Bidirectional call outs

marshell, greenimi, Woosang,

As long as we are talking about single pattern only and the positional callout defining cylindrical tolerance zones is wrt A only, there is no geometric difference between composite and two single segments callouts.

RE: Combining Composite and Bidirectional call outs

pmarc,
I agree. But what is shown in the sketch is not composite..... (as the OP title states).
Do you agree?

RE: Combining Composite and Bidirectional call outs

pmarc,
You mean that since neither datum B or C is referenced, they can't restrict the position of the hole pattern, don't you?
I might have been confused with that.
Thanks.

RE: Combining Composite and Bidirectional call outs

greenimi,
If you are talking about the second sketch posted by OP - the one where he modified his original sketch according to my suggestion - then yes, this is not composite callout.

Woosang,
Yes, no reference to B and C in the position callout means hat callout does not control location of the pattern. The only locational relationship controlled is spacing between the holes.

RE: Combining Composite and Bidirectional call outs

Quote (marshell)

I want to allow the hole pattern to float in a large, rectangular zone, but I want to ensure the hole to hole location of the pattern stays tight in a normal circular zone.

The |Ø.010(M)|A| refines the orientation (perpendicularity) relative to datum A, so it seems to me that you haven't (yet) refined the hole-to-hole location. Or did I misunderstand what you mean by hole-to-hole location?

RE: Combining Composite and Bidirectional call outs

Gilmiril,
Notice that the |Ø.010(M)|A| callout is Position not Perpendicularity, thus hole-to-hole location is controlled (in addition to perpendicularity).

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