refine orientation of an angle with an orientation call out or composite the location?

[ronj100]

Hello,
See the link to the sketch

https://dl.dropboxusercontent.com/u/45474807/New folder/sketch3.jpg

The intent is to locate the start of the angle with a position tolerance.
The the tolerance of the angle can be greater, but its important that the angles perpendicularity is refined to datum B.
My question is if the perp refinement is better done by changing the position frame to a composite frame. Maybe both ways work. Maybe not. What do you think?

 

[CheckerHater]

Measure angle directly from [A].
Specify Angularity wrt [A|B].
Drop Perpendicularity.

 

[ronj100]

Sorry, Please expand on line#2 (wrt)

 

[CheckerHater]

With Regard To, or Relation(ship) if you please

 

[ronj100]

So what does that mean?
Are you saying to turn the position frame into a composite frame?

 

[CheckerHater]

Just a single frame [ANG|DIA.024|A|B]
[ANG|DIA.024|A|C] may work as well.

 

[ronj100]

That does not make sense to me.
The tolerance of .024 would then be the same for the angle as well as for its perpendicular relationship to datum b.
I need perpendicularity refined tighter than the position or the angle.
What am I missing here.

 

[CheckerHater]

I am not sure I understand what "position of the angle" or "perpendicularity of the angle" means.

 

[CheckerHater]

Or "start of the angle" for that matter.

 

[ronj100]

The position of the angle is defined by its start point in the top view.
What I want to refine is the perpendicularity of the cylinder to datum B.

 

[CheckerHater]

Then apply your perpendicularity to the cylinder.
I would suggest applying angularity to the cylinder as well, but its value has to be smaller than positional tolerance, because orientation may only refine position. Your .014 position tolerance is already holding your cylinder tighter than .024 angularity tolerance.

 

[ronj100]

Please look at the print and try to see what Im after.
That start point of the cylinder has to be at a certain position. (.014)
But the angle of the cylinder does not need to be held tight. Only to +/- 1 deg.
And the orientation, whether it be perp to -B-, or parallel to -C- (but in this case B matters), has to be around .0015.
These are all vaiid design constraints. What would those constraints look like on a print?

Anyone else out there want to chime in on This??

 

[SeasonLee]

The through hole Ø.813 is a single feature (of size) only, so you cannot use composite position control to refine the perpendicularity since composite position control is typically applied to a pattern FOS, a composite position control is never used on a single FOS.

The angle of the hole can be controlled by the position FCF, so I will delete the angularity and perpendicularity callout, and the perpendicularity refinement can be done by multiple geometric controls as shown on the attached.

Season

 

[CheckerHater]

“Position” you apply on your print has nothing to do with the point.
It applies to the entire cylinder. In fact, GD&T is not very fond about positioning imaginary objects such as points. GD&T may control point, axis, or plane derived from physical feature, but it is always about physical features first.
If you find me annoying, I will be glad to leave you alone for a while. Let’s wait for someone else to chime in.

 

[SeasonLee]

CH
You are right, absolutely agree what you said.

SeasonLee

 

[pmarc]

Some aspects of design constraints are not clear to me:

1. Perpendicularity of hole's axis to B? How is it even possible? From what I see the only orientational relationship to B that could be applied is Angularity. Am I missing something?

2. What does it exactly mean to you: "the angle of the cylinder does not need to be held tight. Only to +/- 1 deg. And the orientation, whether it be perp to -B-, or parallel to -C-(but in this case B matters), has to be around .0015." In other words, which directions do these values exactly apply to? Could you clarify?

 

[CheckerHater]

Perpendicularity of hole's axis to B? How is it even possible? From what I see the only orientational relationship to B that could be applied is Angularity. Am I missing something?

Pmarc,
There is cylindrical perpendicularity and planar perpendicularity.
The axis of the cylinder is laying between two parallel planes 0.0016 apart from each other and perpendicular to

 

[ronj100]

The last post described the perpendicularity that the customer wants.
The cutomer, however, wants that cylinder to start at a certain point. Obviously that point can be determined by a cmm off a physical feature. But its still a point, and the customer wants it controlled to position tolerance of .014.
He also stated that the angle can vary +/- 1.
Hey, I understand the customer. Makes sense to me. I'm just trying to communicate those constraints on a print.
I appreciate all the help. I'm learniong much, thats what this is all about.

Seems the only thing left that I need to understand is how to control the start point of the cylinder (and yes, that point exists because my inspector can tell mne where it is) and yet allow the angle more tolerance than its start position.

 

[pmarc]

ronj100,
So where does the .0015 come from? Was this value somehow calculated basing on +/-1 deg requirement or is it an additional demand?

 

[ronj100]

Sketch in CH last post describes that.
You can hold that cylinder to .0015 in that plane, still have +/- 1 in the other plane (or axis) and still have a controlled start point.
The start point of the cylinder could almost be looked at like a rotational point or pivot point. the cylinder can rotate +/- 1 deg in one axis but only a small amount (.0015) in the other. However, that pivot point has to be controlled also by a position of .014.