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Datum shift

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powerhound

Mechanical
Joined
Jun 15, 2005
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Hello everyone,
I have a question regarding datum shift. Is it okay to specify a datum shift modifier while the feature being controlled is RFS? If it is legal, does it really make sense? If there is a section in the standard that specifically addresses it, I couldn't find it. If you know where it is, would you please enlighten me?
Thanks,

Powerhound
Production Supervisor
Inventor 11
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SSG, U.S. Army
Taji, Iraq OIF II
 
I could be mis-understanding your question. But from my experience I would say the answer is no. I have never seen a datum shift without some sort of MMC or LMC condition applied. These conditions give you the bonus zone that allows the shift to occur.

 
Likewise, unless I'm misunderstood also, on the contrary, I would say it is legal. Datum shift comes from MMC/LMC callouts on your Datums and it's legal when your datum(s) are Features of Size (FOS). Additionally, you can choose to control your feature with RFS/MMC/LMC where MMC/LMC, for FOS, would give you additional bonus tolerance as the feature departs from MMC/LMC.

 
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