Part Quantities When Using "Stacked" Balloons

[092961]

When using stacked balloons that apply to multiple locations of parts on an assembly, is it more "accepted" to place the "2X" beside the first balloon with the assumption that the fabricator will understand that the quantity applies to all balloons in the stack OR place the "2X" beside every balloon in the stack?

Note that I use SolidWorks but do not use the split balloon feature in the software for other reasons, so this is not an option.

Thanks in advance for feedback!

 

[CorBlimeyLimey]

I think you will find it is more accepted to use a BOM with a QTY column rather than add a separate QTY note to balloons.

Is the QTY note parametric?

Is there a reason (company standard?) which does not allow the use of a BOM with QTY?



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[092961]

The balloons refer to the BOM item number, however the BOM lists the total quantity whereas the balloons show the quantities of each part (or set of parts for stacked balloons) AT THAT LOCATION.

 

[ctopher]

In your case, have the item qty next to each balloon. But, item numbers are only used once in a balloon. If used again, it has parenthesis as ref. In addition, have the BOM show total qty for each item also.

Chris
Systems Analyst, I.S.
SolidWorks 06 4.1/PDMWorks 06
AutoCAD 06
ctopher's home (updated 06-21-06)

 

[ewh]

Back in the drawing board days, we used to handle this by placing the qty near the center of the balloon stack, and using a bracket to include all of the balloons. I still do this occasionally, since the qty isn't associative to the balloon anyway (in the CAD system I use), but instead of a bracket, I use a line (much more efficient).

 

[11echo]

This might help, but back in my board days I didn't use balloons, I used hexagons! This shape lends itself very well for stacking or putting side by side. You'll end up with a "bee hive" affect, but looks "clean". Actually I hated having to do this listing of parts, always seemed like a waste of time. In my discipline, I always thought if a guy didn't know what a piping elbow was, he didn't need to be looking at the drawing! ...But that's just me. ...Mark

 

[aardvarkdw]

Mark,

There are idiots in every field... it is best to produce drawings that are idiot resistant, not idiot proof, they will just make a better idiot. In my opinion that means labeling everything.

 

[11echo]

Aardvarkdw ...No such thing as "idiot proof …or resistant" and actually I think the other way, make the drawings as technical complicated as possible to "scare" the idiots away. So far in my career it "seems" to have worked! ...That and shop/field people know who to come to when they have questions ...which actually works at stopping problems (how novel! *G*). AGAIN my own rantings/ravings! …Mark

 

[wgchere]

But, item numbers are only used once in a balloon. If used again, it has parenthesis as ref.

An item no. can be used in a balloon as many times as is necessary. When it becomes a ref is if a particular instance of an item is called out again.

For example: I have in my BOM items 1 (screw), 2 (lockwasher), 3 (flatwasher), & 4 (nut), qty of 12. My drawing has two paterns of these screws, one 4 holes, one 8 holes. Each pattern will be called out seperately in stacked balloons, one qty of 4, one qty of 8. In a section, I show how the items are assembled and call them out again. This time they will be references--with no qty.

 

[ewh]

"When it becomes a ref is if a particular instance of an item is called out again." Or when the item is accounted for in a qty callout, which is pretty much the same thing.

 

[drawoh]

092961,

I have used stacks of split item balloons to show how many fasteners are required to attach specific parts. This is particularly helpful when you are using the same screw, over and over again. Using the same screw over and over again is good design practice.

My box, item 15 is attached using 4X item_22. Another box, item 28 is attached using 6X item_22. The parts list will show at least QTY_6 of item_22.

SolidWorks does not support this, but the work-around is trivial. I systematically customize the QTY part of the split balloon. Changes to the parts list will be caused by me using the screws elsewhere, and the action tracked by the parts list. If I do change the number of screws in the part, I know I must fix my assembly drawing. Again, the parts list will be correct.

I would use the split item balloons if at all possible, because I would not want to have to keep your "2X" text next to the balloons as I moved stuff around. Your drawing will quickly turn into a mess. I am still on SW2003. Perhaps the newer versions allow you to attach text to item balloons?

You need a convention on what it means when 2X item_15 is attached by 4X item_22. Is that a total of four screws, or is it 2X2? I prefer the absolute total.

In the past, on a drafting board or on 2D ACAD, I have carefully placed the 2X right next to the balloon. I used curly brackets to quantify the entire balloon stack. As noted above, I would not dare do this on 3D CAD like SolidWorks.

I have seen a number of people create balloon stacks of fifteen to twenty parts. I hate this. As an assembly instruction or specification, it is practically useless.

JHG