Position tolerance - Offset feature

[Sa-Ro]

Hi

How to locate a hole - offset from center plane.

Refer drawing. Which one is correct - Method A / Method B

Thank you.

 

[Burunduk]

Method 2, where the basic dimensions are given from the datum center planes, is correct.

 

[drawoh]

Sa-Ro,

What is positioning your part? If your lengths and widths are accurate, your use of FOS datums is a good idea, and your right-hand view is good. Your real alternative is to define two edges as your datum features.

 

[Sa-Ro]

Burunduk

Thank you.
___________
Drawoh

I have a female part of same size with a projected shaft which pass through the hole..

Thank you

 

[Tarator]

Sa-Ro,

Assuming your part is fully defined, it does not matter where you place your basic dimensions. So both methods would be correct. However, Method 2 should be preferred.

Please see the following video:

https://www.youtube.com/watch?v=AfgBF0VKpbs&t=13s

 

[Burunduk]

Tarator,
This case may be different from the one in the video. In the video, there was a chain of basic dimensions from the datums to the toleranced features. But here, if the 100 and 5o dimensions (datum features of size) are directly toleranced, there is no basic relationship from the center plane datums to the lateral faces from which the basic dimensions to the hole are given.