correct use of angularity

[duk748]

hello - i have a question on the use of angularity in this application as attached - the important feature is the relationship of the bore in the arm w/ the keyway to the orientation (angle) of the square - i m not sure if as my example shows angularity is the correct feature to use - any help or suggestions would be greatly appreciated - thank you in advance

 

[PaulJackson]

Angularity is an orientation control so the fearure control frame needs to have at least one datum feature specified to establish an orientation to compare the feature orientation to. Angularity could be used for the special orientations "parallel" or "perpendicular" but it is typically reserved for anything other than that. When a feature is at an angle other than 0 or 90 its percieved angle changes as the feature rotates (think of a sun-dial)... so typically two datum features are needed to constrain rotations necessary to measure a feature's angularity.

Your example has a number of problems:
Datum feature A is a circle (or cylinder) which constrains no rotations in the view that it is shown.
Your angularity control has no datum features referenced and it is difficult to discern what feature is being controlled... one edge? the square? etc.

Paul

 

[duk748]

hello again & thank you for thr reply - i need to control the angle of the top surface of the square to the keyway angle in the "a" bore - this is a very crued example of what i m trying to accomplish thus the reason i submitted this to the forum - any other help or suggestions on how to achieve what i am asking would be greatly appreciated - thank you

 

[PaulJackson]

See sketch
One way to use the angularity callout.

I doubt that the hole is the functional primary unless it is sufficiently deep but there are lots of things we do not know about your problem.

 

[duk748]

hello again & thank you so much - i knew there was a way to do this but just could not seem to come up with it - thank you again - it has helped teach me just a little bit more then the basics of gd & t - thank you again

 

[MechNorth]

PJ, you forgot to guide duk to location before orientation. The face(s) need to be located wrt the datums before they are refined for orientation. In this case, a composite surface profile or a single segment surface profile with an angularity refinement fcf below it would do.

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

http://www.profileservices.ca

TecEase, Inc.

http://www.tec-ease.com

 

[pmarc]

Jim,
I think Position applied to the width of the angled square can work as well, although at least one basic linear dimension is missing on the print for that.

 

[MechNorth]

Ah, I looked too quickly again and didn't notice that PJ's callout was on the width of the square rather than the single face as originally indicated. Then for PJ's callout, yes, a position would be appropriate. Per the original surface callout, a profile control would be appropriate. All depends on functional intent. Tks.

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

http://www.profileservices.ca

TecEase, Inc.

http://www.tec-ease.com