Dimension a square from a centreline

[AshleyI]

Hi,

I am currently dimensioning up a drawing in which there are some rectangular slots. The slots are driven by a centreline which has to be central to the slots. The way we would normally dimension this would be to put a basic dimension to from the centreline to one of the sides of the slot, however, this means that one side of the slot will be "exactly" a distance from the centreline and the other side of the slot is governed by the dimension tolerance and so could move the centre of the slot away from the centreline it is to be driven by.

Is there some kind of callout or dimension feature that can be used to show that the slot centres are in line with the centreline?

I have done some looking around and the closest that I have gotten to a solution is a BSI which I believe shows what I am after but doesn't go into detail about how to use it. (

http://shop.bsigroup.com/upload/Standards & Publications/Manufacturing/BIP2155-Chapter1.pdf)

(Bottom of Page 9)

If any clarification is needed please ask.

Any help is appreciated and if someone can point me in the right direction to finding a solution myself that would be great.

 

[KENAT]

This image from thread1103-286023 may be of help.

http://files.engineering.com/downlo...5d4-0016863ecd9f&file=connector-cutouts-5.tif

from thread1103-213205 might be some help too.

There are probably other relevant discussions on forum1103 and that may be better place in future - the drawing standards are ASME not ANSI for the last few decades so relevant folks may not be in this forum, there is an ASME mechanical code forum but that is more about ASME compliant 'parts' and boiler codes... than drafting.

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[AshleyI]

Kenat,

This has pointed me in the right direction and it is a symmetry tolerance that I want to be using.

Thanks for the help

 

[KENAT]

If working to ASME Y14.5M-1994 no you probably don't want to be using Symmetry tolerance.

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