yang686526

basic dimension without position tolerance
hi,
is it correct to have only basic dimension without a position tolerance for a part ?
check out our whitepaper library.
are you using another type of geometric tolerance? if not, then the basic dimension only, is incomplete definition.
weavedreamer,
please see the attached example, that would explain more precisely. dimension which is questionable is 54.52
it looks like a tolerance of position to me.
yes it is but given on surface which means simulated plane will be parallel to surface at a distance of ± 0.05, but this toleranc is applicable on angular basic dimension and not on 54.52.
the 54.52 half locates the basic angle vector. consider fig. 5-28 on pg. 129, fig. 6-22 on pg. 174
there is a similar example in iso 1101 p37, only difference being datums precedence is otherway but tolerance zone remains same.
what i do not understand is, if basic dimension 35 is not basic would it make any difference. the tolerance zone would still be same ?
which standard are you referencing on your document to have it defined by?
the basic angle does not appear to be able to stand by itself per asme according to the single view shared. another three dimensions appear to be required along with the 54.52 to complete the location of the axis of the positioned feature of size.
iso is a bit outside of my forte.
the way i read it...
the position callout controls the "vertical" position of the circular end face from datum "a".
tyagimayank,
the standard for gd&t is that each feature has a dimensional requirement it must meet. if you change your positional tolerance to a profile tolerance and add two more datums, your drawing will meet this standard. the lack of datums b and c make your drawing ambiguous.
it has been pointed out in one of the other threads that positional tolerances are for features of size.
jhg
looking at that example again, iso appears to treat that position callout similar to asme using a profile of surface callout.