Chain dimensions using Basic number x and = sum

[tooldeziner]

I have scoured my copy of ASME Y14.5 1994 looking for the dimensioning for multiple holes that uses a BASIC hole to hole dimension x the number of holes = the sum of the BASIC dimension x the number of holes. I have been told that it is legal, but I can't find it in the standard. For my money, just giving the number of spaces and the BASIC dimension is fine; doing the math to add up the sum doesn't change or refine anything. Can someone tell me where this is covered in the standard?
Thanks

 

[KENAT]

Well, though not explicitly mentioning basic dims, 1.7.7 & figur 1.18 are relevant as is section 1.9.5 - especially 1.9.5.2.

I don't think extrapolating to basic is a big jump in logic.

Personally I don't' think it's worth the effort but the standard appears to support it.

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[tooldeziner]

Thanks for replying Kenat. Fig. 1-54 shows the method that I was looking for, but doesn't use BASIC dimensions; probably why I didn't see it when I was "scouring" the standard. The only usefulness I can see in this method is a little effort saved by a lazy draftsman, since the stackups will be the same as chain dimensions. Thanks for your help.

 

[Belanger]

There are several examples in that standard that show the "x times basic" method for circular patterns. Check out Fig. 5-8 at the top of page 88. Also a division-type basic given for the angle in Figure 5-32. But I'm not quite sure if this was the gist of your question.

John-Paul Belanger
Certified Sr. GD&T Professional
Geometric Learning Systems

 

[ewh]

It can also serve to limit "clutter" on a drawing, and is not necessarily the result of a lazy drafter.

"Know the rules well, so you can break them effectively."
-Dalai Lama XIV

 

[KENAT]

I must be misunderstanding the point, how does adding extra text that 10 X 20 "(=220)" reduce effort or make a lazy drafter?

Why not just 10 X 20?

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