Basic Questions

[cloud11]

Hi experts,

Is it posible to have only one datum for a true position callout as shown in the picture? Is the 2*SQR(x^2+y^2) formula still valid in this case? If so, then the .720 will have +/- 0.020 tolerance? Thanks.

Cloud

 

[lifttrucks]

Are you using the ASME Y14.5 standard?

 

[powerhound]

Agree with lifttrucks. This scenario is highly dependent on which standard you're invoking on the print. Per ASME Y14.5 it is not even legal. Per ISO, it is.

John Acosta, GDTP S-0731
Engineering Technician
Inventor 2013
Mastercam X6
Smartcam 11.1
SSG, U.S. Army
Taji, Iraq OIF II

 

[cloud11]

It is an ISO 8015 if not mistaken. So, the formula can be applied? And, the tolerance for .720 should be +/-.020? Thanks.

 

[MechNorth]

Per ISO, the callout is fine. The formula? That's the error on the position of a feature of size based on its delta-x and delta-y values wrt the basic location. The "simple conversion" of the pos 0.040 is simply +/- half the position tolerance for a planar surface location.

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

http://www.profileservices.ca

TecEase, Inc.

http://www.tec-ease.com

 

[fsincox]

The formula you are thinking of is not for this type of application of position, this is clearly ISO and is OK for ISO a single datum is fine here.