True position question - hole on angle

[ywsbek]

I have a noob question here, will the hole be moved in the x,y position using trig or in absolute x,y +/-.25?
TIA


TP1.jpg

[Kelly_Bramble]

The cylindrical tolerance boundary is oriented at the 45 degree angle and located absolutely at the dimension distances (assuming that the dimensions are basic or TED) from the datum features. So to say that the hole will be moved in the x and y is incorrect as I understand your question.

The as-build hole feature axis must fall within that cylindrical tolerance boundary from the start of the hole to the end.

[PhoneboxAngel]

Hi! New to the forum here.


1. The tolerances are not boxed, so they are not TED.
2. The position tolerance datums to A and B, so only three degrees of freedom are constrained.
3. The tolerance zone must be perpendicular to the primary datum if the 45° angle is not boxed.
4. Even if we assume that the 88.8, the 36.8 and the 45° are supposed to be TED, another dimension is still missing, so the tolerance zone wouldn’t be a cylinder, it would in fact be a slot.
5. The drawing is total xxxxx.
6. Considering there’s a decimal comma instead of a point, the drawing is most likely from Germany, Austria, France etc. I’m from Germany, too, and I often find that German designers often know nothing about GD&T, but keep insisting on making such cute drawings that leave you puzzled. I like American drawings much better.

[Kelly_Bramble]

Hi! New to the forum here.


1. The tolerances are not boxed, so they are not TED.
2. The position tolerance datums to A and B, so only three degrees of freedom are constrained.
3. The tolerance zone must be perpendicular to the primary datum if the 45° angle is not boxed.
4. Even if we assume that the 88.8, the 36.8 and the 45° are supposed to be TED, another dimension is still missing, so the tolerance zone wouldn’t be a cylinder, it would in fact be a slot.
5. The drawing is total xxxxx.
6. Considering there’s a decimal comma instead of a point, the drawing is most likely from Germany, Austria, France etc. I’m from Germany, too, and I often find that German designers often know nothing about GD&T, but keep insisting on making such cute drawings that leave you puzzled. I like American drawings much better.

I'd like to point out that we do not have the full engineering drawing before us...

My comments to your's:

1. There could be a note stating that all dimensions are Basic or TED unless otherwise specified. We don't know without the entire engineering drawing.
2. Nothing wrong with the datum's specified. The depth location of the hole feature from the planar surface could be given as a limit tolerance. Most engineering drawing (US, EU or other) include a default tolerance specified within a note or the title block. The orientation may actually be specified within one of these. Again, we don't know without the entire engineering drawing.
3. No such requirement, rule or otherwise in ANSI, ASME or ISO standards.
4. The tolerance zone is a cylinder as specified regardless of the datums specified within the feature control frame (Tolerance Frame). There are applications where position tolerance can be used without ANY datum references.
5. The drawing is incomplete.
6. Comma, I've seen many engineering drawing created in America with this convention.

[Belanger]

And, the current datum scheme actually controls 5 degrees of freedom.