true position of a rectangular feature
true position of a rectangular feature
(OP)
Hi,
I'm working on a project where I want to control the true position of a rectangular feature within a diameter tolerance zone to 3 datum's. My problem is that we want to check this new part with a Gage with round holes in it, and so the tolerance zone we will be inspecting will not be circular but oval. This is because the feature is rectangular. Is there a way to call out an oval tolerance zone on a drawing or am i pretty much stuck with calling out a rectangular true position zone? I would go that way but I don't want to loose the tolerance gained by calling out a oval zone.
thanks,
kyle





RE: true position of a rectangular feature
I assume this rectangular feature mates with round hole in real application, correct? If not, you have to be aware that your inspection method is not really proper to verify the design against its functionality. That is the first thing.
If however verification with the use of a gage with round holes is functionally justified, I would suggest utilizing diagonals of the rectangular feature in conjuction with positional tolerance at MMC in order to find a virtual condition boundary at diagonal directions. The minimum diameter of gage hole will be determined by that VC size.
RE: true position of a rectangular feature
RE: true position of a rectangular feature
John-Paul Belanger
Certified Sr. GD&T Professional
Geometric Learning Systems
http://www.gdtseminars.com
RE: true position of a rectangular feature
Powerhound, GDTP S-0731
Engineering Technician
Inventor 2010
Mastercam X6
Smartcam 11.1
SSG, U.S. Army
Taji, Iraq OIF II
RE: true position of a rectangular feature
I do not see a reason why both diagonals could not be treated as FOS - two sets of two opposed elements (corner edges) associated with size dimensions.
Ksplice,
Positional callouts on diagonals should not have diameter symbols preceeding tolerance values, but (M) modifiers need to be there in order to introduce virtual condition concept.
RE: true position of a rectangular feature
Powerhound, GDTP S-0731
Engineering Technician
Inventor 2010
Mastercam X6
Smartcam 11.1
SSG, U.S. Army
Taji, Iraq OIF II
RE: true position of a rectangular feature
John-Paul Belanger
Certified Sr. GD&T Professional
Geometric Learning Systems
http://www.gdtseminars.com