position tol of a slot 2

[dho]

here is the drawing callout.
a slot of .335/.330 long and .215/.210 wide with full radius at the ends. basic dimensions to X and Y.
under the length, pos .010 M to A B C, under the width, also pos .010 M to A, B, C.
how to interpret it?
is the second pos too many?
how to include max material condition in this case?
thanks.

 

[3DDave]

The callout is OK. It may be a good limitation on the feature, but it's a

Two considerations for feature acceptance, assuming that A is perpendicular to the slot opening.

1) That the slot is within the size limits for the length and width
2) That the slot not encroach on a idealized feature that is the least width - position tolerance and least length - position tolerance that is centered on the true/basic location and is perpendicular to the primary datum.

The idealized feature in this case is .330-.010 = .320 long and .210-.010 = .200 wide.

 

[pmarc]

Assuming the drawing is per Y14.5-2009, the callout is OK - see fig. 7-34 for interpretation, although according to para. 7.4.5.1: "Where the same positional tolerance can be allowed for both [length and width], only one feature control frame is necessary, directed to the feature by a leader and separated from size dimensions"

If Y14.5M-1994 governs the print, the word BOUNDARY is missing below both feature control frames.

 

[Tunalover]

Actually the note BOUNDARY is reserved for when profile is used to control the size of an irregular feature while position is used to control its position. See Figure 6-19 of Y14.5M-1994. The BOUNDARY note does go under the single positional tolerance feature control frame in that instance. This technique permits a more natural positional tolerance zone than the two rectilinear ones described by the OP.

Tunalover

 

[pmarc]

Actually the note BOUNDARY is reserved for when profile is used to control the size of an irregular feature while position is used to control its position. See Figure 6-19 of Y14.5M-1994.

Looks like we have different versions of Y14.5M. Mine shows the note BOUNDARY applied under two position fcfs in fig. 5-47 ;-)

 

[dho]

thanks to all.
Y14.5-1994, fig 5.47
Y14.5-2009, fig 7.34

 

[TheTick]

Usually one sees this type of position scheme on slots when the width location is controlled finer than the length position. Having the same tolerance in each direction loses any advantage.