True Position of Rectangular Slots

[Ksplice]

Hi,

If I call out the true position of a rectangular slot in only in the x direction, does that apply in the Y direction as well or only in the X direction?

thanks

 

[dingy2]

I agree that the feature does not fit a definition of a feature of size per 94 standard but does fit it in the 2009 1.3.32 (b) "a directly toleranced feature or collection of features that may contain or be contained by an actual mating envelope other than a sphere, cylinder or pair of parallel planes."

Dave D.

http://www.qmsi.ca

 

[MechNorth]

Dave, you agree????? ;~}

Jim Sykes, P.Eng, GDTP-S
Profile Services

http://www.profileservices.ca

TecEase, Inc.

http://www.tec-ease.com

 

[Ksplice]

working in ASME Y14.5-2009

 

[dingy2]

Jim:

You stated "Also, no tolerance on the width of the feature. And the location dimension from the edge to the center of the datum-C feature is not basic.
Profile is a far better choice. "

I agree that the tapered holes do not show size tolerances and they must. I have a hard time understanding why there needs to be a basic dimension from datum C to the edge unless the edge is shown in a profile. I do see a .526 dimension.

If the holes were toleranced, we could calculate the MMB of each hole in one direction so I would rather use positional versus profile. It is possible to have a checking fixture with tapered pins locating on true position for the location of the holes in one direction.

Dave D.

http://www.qmsi.ca

 

[MechNorth]

The .526 dimension is not directly toleranced, nor can it be. Please show me how you would hold a measuring tape at the center of the slot. It's not marked as basic either. In essence, it's an inappropriate dimension. There are different positional controls at the top and bottom of the slot; what controls the faces in between? There is a 4-degree dimension, but does the designer really want an angular tolerance zone? At which point is the inflection of the angular tolerance zone; top, bottom, mid, somewhere else? You can do a unilateral profile tolerance if that's the goal you seek. Profile is by definition a boundary control rather than a control of absolute position and absolute size. I would reject a drawing like this unless the designer could prove to me that all of these questions (and more) are fully resolved.

Jim Sykes, P.Eng, GDTP-S
Profile Services

http://www.profileservices.ca

TecEase, Inc.

http://www.tec-ease.com