Standard for BOM Ballons>
Standard for BOM Ballons>
(OP)
What is the Standard when applying BOM Balloons to an Assembly Drawing that contain more than one of the same component?
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS Come Join Us!Are you an
Engineering professional? Join Eng-Tips Forums!
*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail. Posting GuidelinesJobs |
Standard for BOM Ballons>
|
RE: Standard for BOM Ballons>
Chris
SolidWorks 08 0.0/PDMWorks 08
AutoCAD 06
ctopher's home (updated 10-07-07)
ctopher's blog
RE: Standard for BOM Ballons>
I've seen both other methods.
RE: Standard for BOM Ballons>
Chris
SolidWorks 08 0.0/PDMWorks 08
AutoCAD 06
ctopher's home (updated 10-07-07)
ctopher's blog
RE: Standard for BOM Ballons>
"Art without engineering is dreaming; Engineering without art is calculating."
Have you read FAQ731-376: Eng-Tips.com Forum Policies to make the best use of Eng-Tips Forums?
RE: Standard for BOM Ballons>
RE: Standard for BOM Ballons>
Total quantities are defined on the BOM. The same part, especially a fastener, could be used in several places on the assembly. Often, I want to show how many screws are needed to attach a part. This can be hard to show on the drawing.
I have never seen it done the top way. I have seen the other two.
JHG
RE: Standard for BOM Ballons>
The bottom is standard, calling out the qty next to the balloon. If another assy view or detail is called out on the dwg, the part can be called out again, but as reference illustrated in the top pic.
The middle pic should not be used.
Chris
SolidWorks 08 0.0/PDMWorks 08
AutoCAD 06
ctopher's home (updated 10-07-07)
ctopher's blog
RE: Standard for BOM Ballons>
Having said that I normally only balloon an item once and without the quantity.
RE: Standard for BOM Ballons>
Powerhound, GDTP T-0419
Production Supervisor
Inventor 2008
Mastercam X2
Smartcam 11.1
SSG, U.S. Army
Taji, Iraq OIF II
RE: Standard for BOM Ballons>
RE: Standard for BOM Ballons>
V
Mechanical Engineer
"When I am working on a problem, I do not think of beauty, but when I've finished, if the solution is not beautiful, I know it is wrong."
- R. Buckminster Fuller
RE: Standard for BOM Ballons>
David
RE: Standard for BOM Ballons>
If further clarity is needed, I would add another balloon, but add "REF" after it.
I have never seen the top method used.
RE: Standard for BOM Ballons>
However, both the middle and the bottom one seem redundant to some extent. On the middle one doing it like this can get messy, especially if you extend it to fasteners, imagine how many balloons you'd end up with if you have a bunch of rivets or something... If there are only 2 item 3's on the entire assy then in the lower one the 2X seems to be duplicating the information in the Parts list which is a recipe for errors (although some CAD systems help with this) and can lead to a cluttered drawing.
Checker Ron & I went thru this a while back trying to determine what the ASME Y14.100 series said but it was difficult to determine an exlicit requirement as I recall. We ended up with the following in our DRM:
So say you use 6 screws on an assy. 4 to hold down a connector and 2 for a bracket. Based on the above I'd balloon one screw on the bracket and one on the connector. If it wasn't obvious that there were 2 on the bracket and 4 on the connector then I'd add a 2X & 4X respectively.
As I recall this was effectively what I did in the UK too though I don't recall it being formally defined.
KENAT, probably the least qualified checker you'll ever meet...
RE: Standard for BOM Ballons>
I have designed assemblies that have had over 100 occurrences of one screw. Needless to say, the screw was used in multiple places.
This is good design practise. If the assembler can put the whole system together with one to three different screws, then selecting screws from the kit is simple.
I have used the split balloon in SolidWorks. Systematically, I type in the quantity value, even if it is correct. The only way the quantity would have to change is if I change the mounting holes of something. The other way the BOM quantity would change is if I add another component that requires more screws.
Getting this all right is easier than it looks. On an assembly drawing of something complex, it makes things clearer. You cannot always get the view that clearly shows each component. Sometimes, things are too complicated for a clear, exploded view, and you have to go back to orthogonal and section views.
JHG
RE: Standard for BOM Ballons>
RE: Standard for BOM Ballons>
I believe it depends on the intended use of the assembly drawing. Often assembly drawings, or portions thereof, are used by people not fluent in drafting convention.
Unfortunately, I disagree with ctopher; I've never seen your top example anywhere in the world on any language drawing. I have seen both your bottom two examples. In my opinion, most clear is a combination of both of them especially for orthographic view assebly drawings.
RE: Standard for BOM Ballons>
Chris
SolidWorks 08 0.0/PDMWorks 08
AutoCAD 06
ctopher's home (updated 10-07-07)
ctopher's blog
RE: Standard for BOM Ballons>
Sorry.. I couldn't resist...:)
Powerhound, GDTP T-0419
Production Supervisor
Inventor 2008
Mastercam X2
Smartcam 11.1
SSG, U.S. Army
Taji, Iraq OIF II