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Balloon quantity standard ?? 2

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tmoxam

Mechanical
Jul 21, 2011
29



This is a drawing question regarding the placement of quantities beside callout balloons.
We are having this discussion in conjunction with the establishment of company drawing standards.
I (personally_ prefer using "x2" positioned to the lower right of the balloon. My colleagues use either "2" or "2X".
I am ok with either of the quantities using the "x" but, fear that a lone number could be left orphaned or that an orphaned number may be confused as a quantity.
I don't think that there is a definite directive in the ASME standards . Can anyone direct me to the appropriate standard ? What do you do at your company and why?

thanx in advance for your assistance.

Tim Moxam
Senior Mechanical Designer
Aversan Inc.
Toronto,Ontario,Canada








Tim Moxam
Senior Mechanical Designer
Aversan Inc.
Toronto,Ontario,Canada
 
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In my company I struggle with such representation in assy drawings. I explain to designers that main document for assembly purpose is BOM but drawing just illustration how it looks like. I use approach from another standard system where it is directly specified. When you start to analyse design in any case you will keep open both BOM and drawing but in case of revision quantity pcl. will update only in BOM.
 

I’ve never seen “real” standard regulating such things, but plenty of “company” standards demanding all kinds of things, for example, balloons representing purchased items to have name, address, and telephone of the vendor right next to them.
I would suggest you and other engineers just agree on something for the sake of consistency. Bad rule is better than no rules at all.
 
"I don't think that there is a definite directive in the ASME standards ."

Well generally for assigning quantities there certainly is a definite directive. Number of places would be "2X".

Now as regards placement etc. specifically applied to balloons, no I don't know of a definitive statement.

Our internal rule is that before or after balloon is fine so long as it's clear and when possible consistent within a drawing.

We only put qty next to a balloon where the same 'item number' is used in more than one application. If the qty to be put next to the balloon would be the same as that in the parts list we don't bother as it should be clear anyway.

Posting guidelines faq731-376 (probably not aimed specifically at you)
What is Engineering anyway: faq1088-1484
 
Cheers, I was going to put teh paragraph number, I looked it up and everything, but apparently lost track of what I was doing and prematurely posted.

Posting guidelines faq731-376 (probably not aimed specifically at you)
What is Engineering anyway: faq1088-1484
 

So, could someone reference paragraph in Y14.5 that is about balloons?

Also I always thought there was a difference between things like BOM “quantity” and “number of places”.
 
thanx KENAT and thanx MechNorth
i AM interested in the paragraph number but, i will look harder for it now.
I always use 2X when referring to a number of features, holes etc. but, i don't recall any specific reference to a "balloon quantity" in any standard. I look forward to being corrected!!
Any comments on the lone number beside the balloon to indicate quantity?

Tim Moxam
Senior Mechanical Designer
Aversan Inc.
Toronto,Ontario,Canada
 
I am with CheckerHater. The convention "2X" defined in paragraph 1.9.5 of '94 and '09 editions of Y14.5 for number of places is in my opinion something different to indicating quantity of the same items in an assembly. Of course this convention can be used, but it is not that any other method will be incorrect.
 

There is nothing wrong with attaching any symbology to balloons per se, especially if everybody agreed on it, and better yet, it is explained somewhere on the face of the drawing.

But trying to duplicate or even replace BOM is in my opinion Costco-sized can of worms.
First obvious reason is that it makes revising drawings more difficult.
Also it creates more opportunities for misinterpretation. I don’t have a book with me but I believe you can duplicate balloon on subsequent sheets “for clarity”. Which immediately raises questions: is quantity next to balloon applied to this sheet? This sub-assembly? Is it global quantity for the entire machine? The BOM is there for a reason.

I realize that practice of attaching additional info to balloons is based on the belief that people on the shop floor will lose anything printed on separate small piece of paper, including BOM, and that belief is sometimes justified :)

So if your project is not very complicated and you made your intentions clear on the drawing, like “Top number in the split balloon is item number per BOM #ABC123, the bottom number is quantity required per the same BOM” you can get away with that.
Just make sure everything is clear for everybody
 
How is 'number of places' not directly applicable to quantities next to balloons?

Posting guidelines faq731-376 (probably not aimed specifically at you)
What is Engineering anyway: faq1088-1484
 
The op never mentioned quantities within the balloon (as I read it), just beside it. I don't recall a detailing standard from ASME pertaining to assembly drawings only; there are some references to them in Y14.3 (new version to be released soon) as I recall, but no standard specifically on assembly drawings. Thus, other ASME standards are applicable. I don't recall seeing/hearing of any other quantity identifiers in standards other than Y14.5, so it is the only applicable one that I know of. Of course, if Y14.5 isn't invoked on the drawing, then it's not an issue from correctness, just from user understanding.

Jim Sykes, P.Eng, GDTP-S
Profile Services TecEase, Inc.
 
Yes there is a standard that covers Assy drawings, ASME Y14.24. Sadly it covers lots of other types of drawings too, and not that much detail in the Assy drawings section..

Posting guidelines faq731-376 (probably not aimed specifically at you)
What is Engineering anyway: faq1088-1484
 

There is also ASME Y14.34 dealing with BOMs, but I don’t think it says much about the balloon placement.

And to clarify using letter “X” as multiplication sign. It is used in meaning “times” as in “3 times diameter 10”, in this case it looks like 3X DIA 10 with space on one side of X. It is also used in meaning “by” as in “2 by 4”, in this case you put space on both sides of X: 2 X 4.

As it was mentioned, there is no written rule for interpretation of balloons: is it 10 times part number 3, or is it part number 3 multiplied by 10.

All that said, this actually gives you some freedom, which brings us back to idea that as long as everybody agreed, your balloons may vary.
 
As far as I know, there's no standard placement for the quantity. ASME standards show a number of options, but not really associated with balloons directly. The only rule that is applied is stated above about "2X". How that is placed around a balloon (and even whether or not to included it) is not defined.

Matt Lorono, CSWP
Product Definition Specialist, DS SolidWorks Corp
Personal sites:
Lorono's SolidWorks Resources & SolidWorks Legion
 
As an old job shopper, I've seen several different methods of defining quantities adjacent to balloons. What I like best is a well defined company DRM which unifies the method of qty definition on assembly drawings; noting that the BOM is the ultimate authority, and assy dwgs must agree with it. My current aerospace company's extensive DRM uses 2 REQD adjacemnt to balloons, vs 2X to specifically separate it from feature callouts in ASME Y14.5. Not a bad way to go.
So Mr. OP, haggle out a unified method within your company and write it into your DRM (assuming you have one).

BTW, can one change their handle in ENG-TIPS? I want to change mine to CheckerLover.
 
[thumbsup2] thanx guys
its been a good conversation



Tim Moxam
Senior Mechanical Designer
Aversan Inc.
Toronto,Ontario,Canada
 
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