Follow along with the video below to see how to install our site as a web app on your home screen.
Note: This feature may not be available in some browsers.
Datum feature C is the feature-of-size width dimensioned as 15 ± 0.1. The way C is referenced in the position feature control frame, Datum C would be the center plane of that width when simulated with 2 parallel planes collapsing from the outsides until they hit the high points.Datum feature C would this be a derived line between the two axis of the radii at each end of the component
It's not a position callout of ±0.05, just 0.05. But yes, it's valid.The True position call out ± 0.05 to Datum feature C , is this a valid call out?
Belanger said:I have a few questions about the sketch, such as what that right-hand view is supposed to be. (A detail view of one of the slots?)
Rwelch9 said:Is datum feature C a mid line or mid plane ?
Rwelch9 said:If it is physical plane like out side edge or face of a component , then surface of a profile is the best option ?
The standard specifies that the datum feature simulator shall of the inverse shape of the datum feature unless otherwise specified. Therefore I would conclude in this case that it should be two internal half-cylinders with adjustable spacing that you can reduce until contact is made with the external half cylinders of the datum feature. The datums I would associate with it are a plane that passes through the two axes of the internal half cylinders of the datum feature simulator (call it datum plane (1)) and another plane (2) perpendicular to the first at the middle of the distance between the axes. The positional tolerance referencing C can control the centering of the 5.9 width feature to plane (1).
To problem is that there is no basic geometry (true profile) to the two 2.95 (5.9/2) radii and it can be argued that the 2 half-cylinders of the datum feature simulator should be also adjustable at size, not just at separation. I'm interested to read what the others here think. This is not a simple or typical case.
chez311 said:I should clarify, it is not dictated purely by the way the tolerances are applied, but by the way the datum feature symbol is applied to the tolerances.
chez311 said:Sort of a nuanced distinction to make I know but let me be perfectly clear - it would not matter if the width were basic or directly toleranced, either way if the datum feature symbol is applied to the width as shown it would imply the simulator is width-shaped.