Funny Datum System

[Farmer]

Hi all. I have a funny datum system that I must use in a new program (please see att.). In pink is my preferred way to orientate the part to the machine. I say that its a funny system because 99 times out of a hundred my secondary datum (B) is my origin but it looks as though my tertiary datum will be my origin for this one. Can this work? How would YOU set up this datum?

TIA









F.

[#2#]

Do you have GD&T callouts for this part? If so, you need to align using the datums in the order they are called out.

[kass_b]

What goodluck said post your gdt you may need multiple datum alignments.

[Wingman]

What Goodluck Said.

This scheme certainly could be problematic. Especially if the print calls ABC (in that order). B as the Secondary could create serious conflict with C and D alignment.
I would think that (functionally) the odds are the Datum Scheme should probably be C-D as Primary, A as Secondary, and B as Tertiary (at least that is how I would own the part).

[Jan d.]

WAS. It will all depend on how the FCF is built. What you show is not that odd, but it certainly could become strange if the FCF's are not used correctly. Post some of the FCF's and we may have a better idea how odd this really is...


Jan.

[Farmer]

Thanks for your input guys, but it looks as though our engineer is going to add mount holes on datum A (They were going to be net pierced post assembly). This I can handle )