Individual feature control in a pattern
Individual feature control in a pattern
(OP)
Hi,
In attached drawing, I want to control the two welded pieces. Look at the two surfaces connected by dash line in upper left view. The perpendicularity tolerance of each surface relative to datum A and B is important. The coplanarity tolerance between them can be larger. It means the two surfaces can be stepped 2mm but each of them needs to be perpendicular to datum A and B within 0.1mm. Because the two surfaces will serve datum feature in next level of assembly, I would like it to be datum feature C in this drawing.
In this case, which callout in the three sheets makes more sense? Or do you have better ways?
In attached drawing, I want to control the two welded pieces. Look at the two surfaces connected by dash line in upper left view. The perpendicularity tolerance of each surface relative to datum A and B is important. The coplanarity tolerance between them can be larger. It means the two surfaces can be stepped 2mm but each of them needs to be perpendicular to datum A and B within 0.1mm. Because the two surfaces will serve datum feature in next level of assembly, I would like it to be datum feature C in this drawing.
In this case, which callout in the three sheets makes more sense? Or do you have better ways?





RE: Individual feature control in a pattern
PLTZF wrt A|B|C will locate two surfaces within 2 mm and FRTZF wrt A will control perpendicularity to A
See Y14.5 Para 8.6 in 2009 or 6.5.9 in 1994
"For every expert there is an equal and opposite expert"
Arthur C. Clarke Profiles of the future
RE: Individual feature control in a pattern
RE: Individual feature control in a pattern
Location and orientation will still be controlled by larger tolerance in PLTZF.
See Fig. 8-21 in 2009
"For every expert there is an equal and opposite expert"
Arthur C. Clarke Profiles of the future
RE: Individual feature control in a pattern
If I understand the standard correctly, using your method, the FRTZF in composite profile control still controls the two surfaces as a pattern. It means it controls perpendicularity, form AND coplanirity.
By the way, I want the two surfaces to be perpendicular to datum A and B, independently.
RE: Individual feature control in a pattern
On perpendicularity to A and B I will have to dig deeper, and since I am still at work, it may take time
"For every expert there is an equal and opposite expert"
Arthur C. Clarke Profiles of the future
RE: Individual feature control in a pattern
I would go with profile callout 2 wrt A|B and refine it with perpendicularity 0.1 wrt A|B. Having said that, I think option #1 is ok, but in my opinion profile and perpendicularity combo is more straightforward.
RE: Individual feature control in a pattern
RE: Individual feature control in a pattern
To pmarc: agree that specifying perpendicularity to control perpendicularity will cause less confusion.
"For every expert there is an equal and opposite expert"
Arthur C. Clarke Profiles of the future