GD&T quiz (job pre-req. test) – part 2 2

[gabimo]

Along the GD&T scheme shown in the picture, an additional functional requirement has been identified by design engineering: Maximum allowable mismatch between features 1 and 2 to be less than 6mm
(maximum allowable distance between the axes of considered features 1 and 2)

The print shall be modified by which option: (choose the best answer; more than one answer could be valid)

a.) Add a lower segment on each position callouts Ø 6 to A and make both positions composite

b.) Add a lower segment on each position callouts Ø 6 to A make both positions multi-single segments

c.) Make OD 1 datum feature D ; add a lower segment within Ø 6 to D on OD 2

d.) Make OD 1 datum feature D; add a lower segment within Ø 12 to D on OD 2

e.) Make OD 2 datum feature D and add a lower segment within Ø 6 to D on OD 1 and make it composite callout

f.) Make OD 2 datum feature D and add a lower segment within Ø 12 to D on OD 1 and make it multi-single segment

 

[pmarc]

gabimot,
Is this exactly how the question was worded? I am asking because since it states: "Maximum allowable mismatch between features 1 and 2 to be less than 6mm"the only possible answer can be c).

a.) will not work because of at least two reasons:
1. Composite callouts can't be applied to single features;
2. The tolerance value in the lower segment of composite callout can't be greater than the tolerance value specified in the upper segment.

b.) will not work because for multiple single segment callouts that contain exactly the same datum feature references the segment with smaller tolerance value always overrides the segment(s) with greater tolerance values.

d.) and f.), although legal, will not work because both will allow the maximum mismatch between axes of features 1 and 2 to be 6, not less than 6.

e.) will not work because it is not allowed to have a composite callout containing totally different datum feature references in both segments.

 

[gabimo]

Pmarc,

I do have some scratch paper left from the test, but I do not have the exact wording and I do have to go by what I remember. I wrote ALL the answers, in order to eliminate them, but not the question/ additional statements.
Might have said: “Maximum allowable mismatch between features 1 and 2 to be equal or less than 6mm”. All that’s possible.

But if it is the latter case, then c.) and d.) would be almost the same and the correct answers would be c.), d.) and f.)
Correct?

Thank you
Gabi

 

[greenimi]

pmarc,

If option b.) would be altered to become datumless (on the lower segment, FRTZF) I guess then answer b can be another valid option.
Not part of the original answer, but for academic purpose only.

Does it sounds "kosher"?

 

[pmarc]

gabimot,
I think you could say that c.), d.) and f.) would be correct answers.
Of course I may be mistaken, but my gut feeling is that the question was designed to have d.) and f.) as correct choices.

greenimi,
Position with no datum feature references could be another valid option - that is true - but in that case I would use just one feature control frame (separated from other two FCFs) with two leader lines pointing at both toleranced cylinders.