Coplanar surfaces using profile callout 2

[janandk]

I need to show the marked surfaces on attached picture to be co-planar. Is this the correct way of showing it. Thanks.

 

[pmarc]

janandk,

Please take a look at attached picture.
In your situation it should be 4X instead of 2X and 0.2 instead of 0.08.
Profile feature control frame leader can be attached to any of 3 phantom lines, just as you already did.

 

[janandk]

Thanks pmarc. My other question was whether I need to specify a datum when using more than 2 surfaces. Your drawing uses 2 surfaces only.

 

[Belanger]

No -- do not reference a datum in that profile callout. (The surfaces may be labeled as a datum for use elsewhere, but not in the profile tolerance.)

It's kind of like checking flatness; the three highest points taken anywhere on those four surfaces form an imaginary plane. That's kind of like the datum that you are thinking of, but it is not referenced as such. Then, all other points across all four surfaces shall not rise more than 0.2 mm from that imaginary plane.

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

 

[dgallup]

In ISO you can use flatness with the text "COMMON ZONE" below the feature control frame. To me that makes a lot more sense than profile, particularly with no datum. I don't think that is legal in ANSI.

 

[SeasonLee]

janandk :

Attached is an example of three coplanar surfaces with profile callout.

SeasonLee

 

[KENAT]

This or related comes up every now and then, I swear there was a nice long thread in the last year or two about it but I could only find thread1103-258254

Posting guidelines faq731-376

http://eng-tips.com/market.cfm?

(probably not aimed specifically at you)
What is Engineering anyway: faq1088-1484​

 

[fcsuper]

Profile instead of flatness? Isn't ASME nudging us to use Positional and Profile more often instead the other callout methods?

Matt Lorono
Lorono's SolidWorks Resources & SolidWorks Legion

http://groups.yahoo.com/group/solidworks & http://twitter.com/fcsuper

 

[dgallup]

Just because some ASME committee thinks it's a good idea doesn't make it so. After all, they tried to kill off symmetry and had to bring it back.

I guess I'm old school, but I only use profile for complex shapes that can not be controlled by the more basic flatness, roundness, cylindricity, etc. I find most shop floor people have a good inherent concept of flatness but their eyes glass over if I say profile.

 

[MechNorth]

True, their knowledge of the term "profile of a surface" is limited, but if they are a machinist, they quickly understand what it means. Don't sell the shop short, and don't dumb things down.

Jim Sykes, P.Eng, GDTP-S
Profile Services

http://www.profileservices.ca

TecEase, Inc.

http://www.tec-ease.com

 

[flash3780]

Just because some ASME committee thinks it's a good idea doesn't make it so. After all, they tried to kill off symmetry and had to bring it back.

I haven't found a good use for symmetry yet; it seems to be along the same lines as a concentricity callout. I suppose that if you have something spinning, a symmetry callout would imply some degree of balance. However, material irregularities usually dictate a dynamic balancing note.

Has anyone out there used symmetry before?

 

[MechNorth]

Seen it used, Yes. Seen it used properly, No. The opposed indicators are the killers, but proponents of symmetry and concentricity seem to just ignore that requirement.

Jim Sykes, P.Eng, GDTP-S
Profile Services

http://www.profileservices.ca

TecEase, Inc.

http://www.tec-ease.com

 

[fcsuper]

I've seen symmetry completely missed used. I've even seen the symmetry simply floated in space (no FCF) near a "centerline" to presume some sort of mirror of groups of unidentified features. Since the symbol was associated with a drawn centerline, the question in my mind was "What is the centerline symmetric too?"


Matt Lorono
Lorono's SolidWorks Resources & SolidWorks Legion

http://groups.yahoo.com/group/solidworks & http://twitter.com/fcsuper