Can one feature be used for both secondary and tertiary datum?
Can one feature be used for both secondary and tertiary datum?
(OP)
I have a simple bracket. It only has a slot hole on it. Can I use the slot as both secondary and tertiary datum? Thanks in advance.





RE: Can one feature be used for both secondary and tertiary datum?
RE: Can one feature be used for both secondary and tertiary datum?
Chris
Systems Analyst, I.S.
SolidWorks/PDMWorks 05
AutoCAD 06
ctopher's home site (updated 06-21-05)
FAQ559-1100
FAQ559-716
RE: Can one feature be used for both secondary and tertiary datum?
RE: Can one feature be used for both secondary and tertiary datum?
Sounds like you need to control the slot w.r.t. the rest of the bracket, not the other way around.
RE: Can one feature be used for both secondary and tertiary datum?
One other thing to think about is how this slot performs when it's assembled in the next highest subassembly.
Best Regards,
Heckler
Sr. Mechanical Engineer
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RE: Can one feature be used for both secondary and tertiary datum?
I agree with TheTick & Heckler.
we368, curious. do you have a copy of ASME Y14.5?? If you don't, you should.
Chris
Systems Analyst, I.S.
SolidWorks/PDMWorks 05
AutoCAD 06
ctopher's home site (updated 06-21-05)
FAQ559-1100
FAQ559-716
RE: Can one feature be used for both secondary and tertiary datum?
I seem to recall a case of a person showing 3 views of the ball bearing, years ago.
RE: Can one feature be used for both secondary and tertiary datum?
RE: Can one feature be used for both secondary and tertiary datum?
Chris
Systems Analyst, I.S.
SolidWorks/PDMWorks 05
AutoCAD 06
ctopher's home site (updated 06-21-05)
FAQ559-1100
FAQ559-716
RE: Can one feature be used for both secondary and tertiary datum?
You need enough datums to immobilize your part. Does applying a second datum to your slot contribute to this?
I can give an excellent example of a part with two datums. I have a round, flat plate with a bolt circle. Datum_A is the bottom face. Datum_B is the outside diameter. The bolt circle has a positional tolerance using datums_A and_B. A third datum has no meaning, unless I add another feature that must line up with the bolt circle.
I keep trying to type "pitch circle". :)
The first hole I drill in ringman's ball bearing can only be located WRT datum_A.
JHG