How do I indicate basic ordinate dims when they line up with the 0,0?

[NortheastMtnBiker]

Hi,
First time poster here. I've searched through the forums and haven't found this exact question.

I'm using ASME Y14.5-2009. I have four holes in a line, and one of the holes is the 0,0. I want the three other holes to be basic since I'm applying a positional tolerance to them (not all positional tolerances shown in the below picture because they are in the other side of the view that I cropped out). How do I indicate the three other holes are basic? My understanding is I shouldn't put the "basic" box around the 0 since the 0,0 does not have a positional tolerance. This is what I currently have. It makes sense to me, but I'm not sure if it's correct.

Thanks

 

[CheckerHater]

From Para. 1.4 FUNDAMENTAL RULES:
(k) A zero basic dimension applies where axes, center
planes, or surfaces are shown coincident on a drawing, and geometric tolerances establish the relationship
among the features. See para. 2.1.1.4.

As long as holes are aligned and positioned using FCF's basic zero dimension implies.

"For every expert there is an equal and opposite expert"
Arthur C. Clarke Profiles of the future

 

[pylfrm]

NortheastMtnBiker,

You might argue that your case does not involve axes, center planes, or surfaces shown coincident. Nonetheless, ASME Y14.5-2009 para. 1.4 (k) is generally considered to cover your case as well. 3X .000 BASIC is not required.

To make it more clear that the holes are aligned vertically, you could connect the center marks as illustrated in Fig. 4-9.


pylfrm