Using 2 points to callout a hole.

[ACarrier]

I am detailing a part that has a face that has been drafted multiple times (using the 'draft' command in Catia). I want to callout a hole that is normal to this drafted face, but I do not know how as I cannot create a view that is perpendicular to any of the axis established by my datums.

I was thinking I could callout the positions of the center points of the ends of the hole (using 2 views in order to establish full 3 coordinates). Then I could say "make a D6.5mm hole coaxial to Pt.A and Pt.B". I think this would work, but I don't know if this method is acceptable or what correct notes are required if I use it.

In any case, what should I do?

 

[CheckerHater]

Is your question actually related to:

a) GD&T
b) CATIA
c) producing drawings depicting compound angle

?

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

 

[drawoh]

ACarrier,

Things that model badly in 3D CAD have a nasty habit of not working for real.

How is your fabricator going to fixture to make your hole? Can you add some fixturing/datum features?

--
JHG

 

[ACarrier]

CheckerHater,
I want to know the correct GD&T or traditional way to properly detail this hole feature in a drawing. So it is about GD&T.

drawoh,
As of right now, we plan on molding the part - hence the multiple drafts.


All I need to know is how to callout a hole feature that is normal to a surface - a surface that has been drafted multiple times.

 

[TheTick]

Sounds like a good place for an auxiliary view or section view.

Judging from the quantity of helpful images already not present, communicating with pictures is not your strong suit.

 

[ACarrier]

Wise guy, ay?

TheTick,
Yes, an auxiliary or section view, except - for the third time - the surface normal to the feature has been drafted multiple times and is no longer perpendicular to any axis; so I'm having trouble creating a view normal to this surface. And I would have released images of this part in my original question if I could, but I cannot.

 

[KENAT]

You could go the lazy route and just use Model Based Definition.

We ended up doing that once on a machined part that had compound angles and then they laid off the designer before he finished the drawings so we were up against the clock without any familiarity with the design.

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(probably not aimed specifically at you)
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[TheTick]

You probably need to get to the projection in two steps. This sounds similar to a compound miter problem, where it takes two projections to get to the true angle.

 

[ACarrier]

KENAT,
That is an excellent idea, and I am in fact using a "CAD IS MASTER" note. However, I still would like to callout (in some way) the hole feature.

Thank you for the suggestion.

 

[MikeHalloran]

The tool used to make the hole in a prototype is different from the tool used to make the faces.
The tool used to make the hole in a mold is different from the tool used to make the faces in the mold.

That the hole intersects a face at some angle other than 90 degrees is of no consequence to the hole, or to the person who runs the tool that makes the hole or its complement.

Dimension the hole from your datums and ignore any relationship it may or may not have to adjacent or intersecting surfaces.


Mike Halloran
Pembroke Pines, FL, USA