Position at RFS: turning coordinate deviations into a position value
How true position is computed from X and Y deviations, why the answer is a diameter, and what regardless of feature size actually means on the shop floor.
12 practice questions on this topic.
Read the guidePosition at MMC and bonus tolerance, explained with the arithmetic
What the maximum material condition modifier grants, how the bonus is computed for holes and pins, and why the allowance is bounded by the size tolerance.
14 practice questions on this topic.
Read the guideLeast material condition: protecting wall thickness rather than assembly
When to reach for the LMC modifier, how its departures reverse every direction learned at MMC, and why it is harder to gauge.
10 practice questions on this topic.
Read the guideVirtual condition and resultant condition, and when neither exists
How to compute the constant worst case boundary in all four directions, what the resultant condition adds, and why there is no virtual condition under RFS.
12 practice questions on this topic.
Read the guideDatum shift: why it is not extra tolerance on the feature
Where datum shift comes from, how much of it a datum feature of size permits, and why adding it to the acceptance limit accepts parts a gauge would reject.
10 practice questions on this topic.
Read the guideReading a feature control frame compartment by compartment
The order of the compartments, where the material condition modifier belongs, why RFS is never written, and what the extent indicators add.
14 practice questions on this topic.
Read the guideDatums, precedence, and counting degrees of freedom
The difference between a datum feature, a datum, and a simulator, how precedence works, and how many degrees of freedom each kind of datum feature constrains.
12 practice questions on this topic.
Read the guideSize limits and Rule #1, the envelope requirement
What a size dimension controls on its own, how the envelope requirement limits form, and when independency removes it.
12 practice questions on this topic.
Read the guideProfile of a surface and of a line, and what one frame can control
How a profile zone is disposed about true profile, the difference between the surface and line characteristics, and why profile can replace size, form, orientation and location at once.
12 practice questions on this topic.
Read the guideRunout: reading an indicator against a rotating part
Full indicator movement, the difference between circular and total runout, and why a runout number is a good requirement and a poor diagnostic.
10 practice questions on this topic.
Read the guideOrientation: perpendicularity, parallelism and angularity
What an orientation tolerance controls and what it deliberately leaves alone, how it refines a position tolerance, and how it limits form as a side effect.
10 practice questions on this topic.
Read the guideForm controls: flatness, straightness, circularity, cylindricity
Why form controls take no datum, what each zone looks like, how much form the size tolerance already implies, and when an explicit callout earns its place.
10 practice questions on this topic.
Read the guideComposite position: locating a pattern and relating its features
How the two tiers of a composite frame differ, why the lower tier repeats only some datums, and what changes if the frame is split into two.
8 practice questions on this topic.
Read the guideFrom a drawing requirement to a measurement that answers it
Sizing a functional gauge, why MMC can be gauged and RFS cannot, what a report has to carry, and the conditions measurements are defined at.
10 practice questions on this topic.
Read the guide