Mech1595,
I agree with 3Ddave as it being a defect, incomplete drawing. Looking at your figure, first of all the flatness requirement is only valid for the lower surface. The CZ means nothing unless there is a "2 x" notation or multiple leaders pointing to other surfaces for the flatness...
Hi,
In ISO, a complete datum system that locks all six degrees of freedom consist of a plane (3 points), a line (2 points, and a point. Much like how an alignment would be in a CMM with spatial alignment, planar alignment and origin.
In your first ISO example, there is only primary and...
Hi James,
I would keep datum "A" as the center line of the bore and tolerance the the outer diameter as UF Ø39 with a position tolerance with respect to "A". I have not done this my self, but for a hex I have seen the following approach being used; 3x 36 h11 with a position tolerance at MMC...
ISO 2768-1 is still valid, 2768-2 is withdrawn but still allowed to use (although ISO will not update it anymore).
It is likely ISO 2768-1 will remain for a while longer due to the wide spread use at least in European industry.
As mentioned, a newer standard for general tolerancing is ISO...
ISO 5459:2011, Annex D.3 reminds us that is a former practice to indicate a common datum established from a group of features with and indication of single datum.
I would say that this is still very common, I see it often in both older and more recent drawings.
As already mentioned above, ISO...
ISO defines it in ISO 5459:2011 as a point, straight line or plane (or helix) from which the location and orientation of features can be defined.
A fully defined datum system locking all 6 DoF would consist of a set of situation features; normally a plane - a line and a point, derived from the...
Thank you for clarifying. Overseeing the primary datum had me off there.
I am new to this forum and hoping to learn more about ASME and ISO similarities and differences.
I see now, that primary datum was C, not D my mistake. @Burunduk, I agree. Still, I am yet to see an example as such in ISO GPS standards.
The associated feature for the cylinder would be min circumscribed per ISO default rule and the situation feature being a straight line - axis of the...
Hi, I am working exclusively with ISO, but have seen examples from ASME Y14.5 in other threads on Calypso forum where they point to figures in Y14.5 that is a similar case where a datum is self-referencing. To me, its self referencing and not something that would be supported in ISO atleast. I...
