Symbol Identification Question 2

[JNieman]

I tried searching but when you don't know what to call thing thing you're searching for, it's hard to find results.

This FCF is attached to a plain hole perpendicular to a flat surface, thru the entire body, with the exit surface parallel to the entry surface. Basically the hole is as simple as geometry gets. Datum A is a plane parallel to the surface the hole penetrates. Datums B & C are holes parallel to the hole-in-question and in the same body.

What I can not identify, however, is what this symbol under the FCF is. My best guess is that it denotes perpendicularity to Datum A, since A happens to be a surface perpendicular to the hole axis. However that doesn't come with any tolerance, unless it's implied some other way I'm ignorant of.

To what spec would this symbol be identified, and what is it?

Drawing is noted to be IAW ASME Y14.100-2004, Dim & Tol per ASME Y14.5-1994.

Image linked and attached

Thank you

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NX8.0, Solidworks 2014, AutoCAD, Enovia V5

 

[pmarc]

For sure this symbol is not defined in Y14.5M-1994.
My best guess would be the same as yours. Perhaps the intent of this symbol is to clarify that the position callout - in addition to acting as location control - also controls perpendicularity to datum plane A.
If that is, by any chance, true, the perpendicularity tolerance is dia. .0050 as defined in the feature control frame.

Side note:
B-C as secondary, and C as tertiary datum reference? That looks at least suspect.

 

[JNieman]

Eh, it's not terribly suspect. Having your tertiary be a point on the same line as defined by B-C isn't too bad. If you go with the "Point on a Line on a Plane" ideal for the best-case scenario for primary/secondary/tertiary datums; I don't figure it matters if the point is a defining point of the line. I can't think of any time I came across this method before, but I don't know that it's very poorly thought of. Knowing the part, though, it's not /bad/ per se.

Thank you for the response. I was afraid I missed some elementary symbolism.

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NX8.0, Solidworks 2014, AutoCAD, Enovia V5

 

[Belanger]

It is kind of suspect, though. If the secondary datum is created from the combined B-C features, then having C be tertiary is probably wrong. Hard to make the definitive call without seeing the print. But that's a tangential issue to your main question

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

 

[JNieman]

Another point in that situation is that this is 100% CMM inspection. There is no physical gage to be made.

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NX8.0, Solidworks 2014, AutoCAD, Enovia V5

 

[ctopher]

I have never seen that symbol, until now.

Chris, CSWA
SolidWorks 14
SolidWorks Legion

 

[HGMorgan]

This looks like a Boeing Drill Code symbol.
Take a look around the dwg (usually sheet 1) for a Drill Code Table.
The table would have:
The symbol, hole size, color code.
Normally used on a drill jig tool with multiple holes of different sizes, I.E. "A" .375 Dia color Red, "B" .500 Dia color Green, etc.

Harold G. Morgan
CATIA, QA, CNC & CMM Programmer

 

[JNieman]

@HGMorgan

Ding ding ding!

This is a Boeing job, and I have not come across this one yet. We have some screenshots and clips of drawings to do an RFQ on a real rush job (and yep, it's a DJ) so I do not have the notes and tables that are likely on sheet 1. This is the first time I've seen this method. For all the other DJs requiring color coding, we've been required to mechanically engrave the drill code and fill it with paint of a specified color.

Always something new with Boeing work - I love it... usually.

Thank you very much.

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NX8.0, Solidworks 2014, AutoCAD, Enovia V5

 

[JNieman]

To clarify, that is our hole ID / Bushing ID reqs have previously been flag noted, and not via a table. This is much cleaner and more efficient, to have a table. But now I'm glad I know what the symbol is, so we can plan on some of that in the design.

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NX8.0, Solidworks 2014, AutoCAD, Enovia V5