Primary to Secondary Datum Structures
Primary to Secondary Datum Structures
(OP)
I'm making my head hurt because I think i'm making something harder than it needs to be.
I have a Circuit board that interfaces with a heatsink through two pins (part of the heatsink) with a hole (Datum B) and slot (Datum C defined by the width). There is a pattern of holes (two Ø.118 and 4 smaller ones) that are for a connector. This is all shown in picture 1.
Link
It is more important for the connector holes (really the Ø.118 ones) to be oriented to the A|B|C datum structure than it is to be located.
Picture 2 seems to make the most sense to me with respect to accomplishing my goals.
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Picture 3 is what i am more used to seeing, what I don't understand is how this controls the orientation relationship between B-C and D-E since Datum E is only positioned relative to A|D.
Link
Thoughts/Feelings?
Thanks,
Pete
I have a Circuit board that interfaces with a heatsink through two pins (part of the heatsink) with a hole (Datum B) and slot (Datum C defined by the width). There is a pattern of holes (two Ø.118 and 4 smaller ones) that are for a connector. This is all shown in picture 1.
Link
It is more important for the connector holes (really the Ø.118 ones) to be oriented to the A|B|C datum structure than it is to be located.
Picture 2 seems to make the most sense to me with respect to accomplishing my goals.
Link
Picture 3 is what i am more used to seeing, what I don't understand is how this controls the orientation relationship between B-C and D-E since Datum E is only positioned relative to A|D.
Link
Thoughts/Feelings?
Thanks,
Pete





RE: Primary to Secondary Datum Structures
Because the only orientation I can see here is perpendicularity to A.
"For every expert there is an equal and opposite expert"
Arthur C. Clarke Profiles of the future
RE: Primary to Secondary Datum Structures
RE: Primary to Secondary Datum Structures
Your picture 2 is the closest thing, although I am not sure if there is the need to introduce more datums into it.
If you could clarify relation between .118 and .018 holes, we could come up with more detailed solution
"For every expert there is an equal and opposite expert"
Arthur C. Clarke Profiles of the future
RE: Primary to Secondary Datum Structures
RE: Primary to Secondary Datum Structures
RE: Primary to Secondary Datum Structures
That will make them one "connector" pattern.
If "tilting" of "connector" to the board still critical, I would add single control to A|B-C to control how much holes can play up and down.
(All that provided all holes are located using basic dimensions)
"For every expert there is an equal and opposite expert"
Arthur C. Clarke Profiles of the future
RE: Primary to Secondary Datum Structures
Checker, what would be the point of doing a|b-c vs just a|b|c?
RE: Primary to Secondary Datum Structures
CODE --> PRuggiero
As long as you know where is the datum point, you will know how to measure and inspect the position of the four small holes.
CODE --> PRuggiero
Please let me know if any missing
Season
RE: Primary to Secondary Datum Structures
To be honest, if all your holes are made "at once", from the same punching / drilling operation you probably don't need all that elaborate scheme.
"For every expert there is an equal and opposite expert"
Arthur C. Clarke Profiles of the future
RE: Primary to Secondary Datum Structures
RE: Primary to Secondary Datum Structures
RE: Primary to Secondary Datum Structures
"For every expert there is an equal and opposite expert"
Arthur C. Clarke Profiles of the future
RE: Primary to Secondary Datum Structures
Season
RE: Primary to Secondary Datum Structures