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Acceptable to have assembly drawing an exploded view?

Acceptable to have assembly drawing an exploded view?

Acceptable to have assembly drawing an exploded view?

(OP)
Hi all.

I have a high level question regarding what an assembly drawing should be.  To me, an assembly drawing should be a three view of the assembly, with auxiliary views and sections taken as appropriate.

I have a designer (technically my boss) who insists on making his assembly drawings as exploded views.  I understand why he does this from a business standpoint (we don't really have a tech pubs dept.), but as an engineer, it just rubs me the wrong way.

Anybody have any experience with using exploded views as the engineering assembly drawing?  I'd like to be able to point to something and say it's a no-no.

Thanks.

RE: Acceptable to have assembly drawing an exploded view?

Is assembly a noun or a verb?

RE: Acceptable to have assembly drawing an exploded view?

(OP)
Noun.

RE: Acceptable to have assembly drawing an exploded view?

Yes, as far as I can discern it is allowed.
Per ASME 14.24-1989 (may be a later revision by now), para 1.4 "Preparation methods... (orthographic, pictorial, or exploded views)... are a concern of this standard only to the extent that the drawing satifies its intended purpose."
ASME Y14.100M-1998 states in para 4.9 that "Isometric or pictorial views shall be in accordance with ASME Y14.4M, and may be shown on engineering drawings provided that clarity is not degraded."
I don't have a copy of Y14.4M, but doubt that it would restrict their use.
I'm sure others will add to this.

"Good to know you got shoes to wear when you find the floor." - Robert Hunter
 

RE: Acceptable to have assembly drawing an exploded view?

I have Y14.4M.  Exploded views are indeed mentioned.  Y14.4M allows a great many types of views, even actual annotated photographs can serve as the drawing.  Using photos to show assemblies was actually my biggest question in this topic before I bought the standard.

bg109g, you might be thinking of "level 3" (if I remember the name correctly) drawings that show a tremendous amount of detail of parts and assembly in very particular formats.  This is not part of ASME standards; I think its a government requirement for particular contracts.



 

Matt Lorono
CAD Engineer/ECN Analyst
Silicon Valley, CA
Lorono's SolidWorks Resources
Co-moderator of Solidworks Yahoo! Group
and Mechnical.Engineering Yahoo! Group

RE: Acceptable to have assembly drawing an exploded view?

Thanks, Matt.  I do remember seeing somewhere that annotated photos were allowable, though I have never seen it in practice.

"Good to know you got shoes to wear when you find the floor." - Robert Hunter
 

RE: Acceptable to have assembly drawing an exploded view?

If the intended purpose of the drawing is to depict what the finished assembly looks like then I'd go for non-exploded.

If the intended purpose of the drawing is to depict how the thing goes together then I'd go for exploded.

There is no reason you can't do both on the same drawing.

RE: Acceptable to have assembly drawing an exploded view?

I agree with the others. Drawings are to depicts how the assy goes together. If it requires an exploded view, then show it. But, I would never show only an exploded view. The only areas that I have shown only exploded views are sometimes on job travelers, marketing brochures, or for customers that request it.

Chris
SolidWorks/PDMWorks 08 3.1
AutoCAD 08; CATIA V5
ctopher's home (updated Aug 5, 2008)
ctopher's blog
SolidWorks Legion

RE: Acceptable to have assembly drawing an exploded view?

I will chime in, exploded views are allowed.  As MintJulep said, it really depends on the purpose of the assembly drawing.  If the exploded view does not add clarity, then it shouldn't be used.

As for photos, when digital cameras because affordable (circa 1996?) I worked at a place that began to use photos for some wiring harness details.  The problem quickly arose after seeing a drawing copied and/or faxed.  It took several months for people to decide which gray scale setting they would use so the inserted photos would survive a few copy/fax actions.  Very ugly.

"Art without engineering is dreaming; Engineering without art is calculating."

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RE: Acceptable to have assembly drawing an exploded view?

I'm against using photos on drawings. I have only seen problems with them when others start copying them. They are good on documents for viewing purposes on a monitor only.
I once worked with a company that decided to make one whole project with photos of it instead of taking the time to draw it. The drawings were full of these wonderful photos. Then the customer received them and could not make copies and reduce them to smaller sheets, the photos turned black. If any changes were needed, new photos were needed, but then that specific product was shipped, the current ones were slightly different because of design changes.

Chris
SolidWorks/PDMWorks 08 3.1
AutoCAD 08; CATIA V5
ctopher's home (updated Aug 5, 2008)
ctopher's blog
SolidWorks Legion

RE: Acceptable to have assembly drawing an exploded view?

As long as an assembly drawing shows all components in their final position and orientation, and accurately describes the finished product all criteria are met. If an exploded view helps show exactly what a component is and where it goes, good, but you must show it in it's final position as well.

The other side of this is that you should NOT be telling someone how to build the assembly or what methods they should be using. These should go in an assembly instruction document.

David

RE: Acceptable to have assembly drawing an exploded view?

(OP)
Thanks for the input.  I'd agree that an exploded view should be a supplement to standard drafting data, and not as the sole depiction of the gizmo.

RE: Acceptable to have assembly drawing an exploded view?

I don't think that there is a hard and fast rule that an assembly MUST be shown in the assembled state, but agree that it is a very good practice to follow.  Unless I actually see "will" or "must" in the standards, I try to avoid absolutes.

"Good to know you got shoes to wear when you find the floor." - Robert Hunter
 

RE: Acceptable to have assembly drawing an exploded view?

(OP)
Not only that, but it's always a good idea to check a few pertinent dimensions after assembly.  Especially if you have similar assemblies which differ in one or two critical dimensions.

How do you dimension an exploded view?  I've never seen it.

RE: Acceptable to have assembly drawing an exploded view?

All of our Assembly Drawings are Mulitple sheets.  We have the Exploded ISO on the first sheet of all the parts and on the other sheets we show the dimensions of the assembly where needed.  The Exploded view helps the person on the assembly line to see what the part looks like and where it goes in the assembly.  It is hard to see the shape of a part just by a cross section or multiple views if you are not trained in blue print reading or have limited assembly views.

RE: Acceptable to have assembly drawing an exploded view?

ASME Y14.24, 4.1.3 Requirements. An assembly drawing includes as applicable, d) depiction of the items in the assembly relationship, using sufficient detail for identification and orientation of the items.

In my opinion, an exploded view, by itself, cannot show the correct assembly relationship and orientation for the simple reason that the parts are not attached in the view. Don't get me wrong though, I think exploded views are great for communicating information. In some instances an assembly becomes too complex to be clearly communicated by sections and auxiliary views alone. I just think that you need to also show the final location of the parts as well.

David

RE: Acceptable to have assembly drawing an exploded view?

I think we agree on most of the points you bring up, David, except that I think, under certain circumstances, an exploded view can show the "depiction of the items in the assembly relationship, using sufficient detail for identification and orientation of the items", thus there should not be an absolute prohibition against using only exploded views.
That said, I don't think that I have ever created such drawings without showing the assembled state and would not recommend it. I feel that an assembled view is essential to show what the envelope actually is and what the assembled part will look like.

"Good to know you got shoes to wear when you find the floor." - Robert Hunter
 

RE: Acceptable to have assembly drawing an exploded view?

I've used exploded views only for assmeblies where the final product does not represent noted componentry (such as assy where everything falls inside two or three parts and where a section view would be more confusing than helpful.  Use of those connector lines can be enough to provide info on what goes where.

Matt Lorono
CAD Engineer/ECN Analyst
Silicon Valley, CA
Lorono's SolidWorks Resources
Co-moderator of Solidworks Yahoo! Group
and Mechnical.Engineering Yahoo! Group

RE: Acceptable to have assembly drawing an exploded view?

I'm actually with aardvarkdw on this one.  I don't believe just an exploded view by itself is adequate, since it doesn't define the end item which is a pretty fundamental principle of most drafting.  Also I believe 1.4(e) from ASME Y14.5M-1994 still applies, so the drawing shouldn't really be showing how to put the item together.

While the wording of 14.24 may not be as clear as it could be I agree that "depiction of the items in the assembly relationship, using sufficient detail for identification and orientation of the items." means showing the final assembled condition.

However, exploded views are allowed as other have pointed out, but I'd only use them in addition to assembled views when they add clarity.

I asked a similar question some time ago: thread1103-157857: Assembly Drawings - Or Instruction manuals and I think there may be another thread too around that time.

KENAT,

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RE: Acceptable to have assembly drawing an exploded view?

Gentlemen,

Other product development activities are moving toward requiring exploded view drawings. Hopefully, the ASME standard can keep up.

Look at the future assembly plant...beside EACH workstation will be an exploded view drawing of some sort.

Drawings of the future will be used to do more. Example...There will be "in-process" drawings used to do things like "kit" parts...to aide in error-proofing.

As processes like FMEAs grow in importance, so will new unconventional looking drawings.

Michael
  

RE: Acceptable to have assembly drawing an exploded view?

Michael, we do a lot of that stuff, but in assembly work instructions or routings etc.  Still fed from the same 3D model but not the drawing.

I could write a long diatribe on the issues we've faced trying to create work instructions based on CAD data before finalizing that CAD data/drawings but I can't be bothered right now.

KENAT,

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RE: Acceptable to have assembly drawing an exploded view?

(OP)
So what you're saying, Michael, is that it will no longer be necessary to read an honest blueprint on the shop floor?

I guess I need to ask for a raise since I will be doing tech pubs work in addition to my engineering duties.  The company could afford it since there will be no need to pay technically competent people in the shop.  Anybody can come in an assemble parts based on the funny paper simple exploded drawings that will be beside each workstation.

As an aeronautical engineer, that scares me.  I realize that for some, engineering has become a repeatable process where only the process gets attention and there is no technical expertise required.  Where is the accountability?  What if the process is flawed in a major way because some ISO certification guy just showed up one day and got taken to lunch and boozed up, after which he signed the certificate?  No sir, this ISO/system/process stuff can be dangerous and we need to be ever vigilant to make sure that "approved" processes and procedures don't end up killing someone.  

RE: Acceptable to have assembly drawing an exploded view?

I do not think it is all about reading or not being able read Blueprints on the floor I think it is a better communcation tool than a cross section showing only a 2D view of what is being assembled.  We have the technology to show animations 3D parts lets make it more clear than ever to get the parts assembled correctly.

RE: Acceptable to have assembly drawing an exploded view?

The intent of a drawing is to communicate. An exploded iso, or possibly an animation of how an assembly goes together, is a better form of communication with the assemblers. Other people may need other views for there needs.

Peter Stockhausen
Senior Design Analyst (Checker)
Infotech Aerospace Services

RE: Acceptable to have assembly drawing an exploded view?

bf109g,

   On my site, my boss is demanding exploded views because production likes them.

   Somewhere in my design documentation, I want orthogonal views with section views and whatever else is need to under what it looks like and how it works.  Often, I do this on a separate arrangement drawing.  

   My perception of the assembly drawing is that it tells someone how to put the thing together.  Assembly sequence, test procedures, orientation of components like belleville washers, and screw torques are as much a part of the design as the intended functionality.      

               JHG

RE: Acceptable to have assembly drawing an exploded view?

As someone who routinely has to work with Assembly drawings, trying to work out what the end item is rather than how to achieve it, I can vouch that the multiple exploded views or step by step sequence is much slower to work with than a conventional drawing, and often omits certain information.

I'm sure it's better for shop floor, but sucks for at least some other users.

That's why I believe exploded views, within reason, should be in addition to views that explicitly show the assembled state.  

Also, I still can't help but think the principle of detailing the end item applies.

KENAT,

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RE: Acceptable to have assembly drawing an exploded view?

(OP)
+1 Kenat.

I've never seen an assembly that couldn't be fully depicted with auxiliary and section views.  I have yet to see a major aircraft manufacturer depict an assembly as an exploded view as part of an FAA approved data package.

Shop documentation is another thing.  If the shop wants an exploded view to assist in assembly, do whatever makes them happy.  Add it to their traveller.  Hold their hands to make sure the -1 goes against the -3.  But when final inspection is accomplished on an FAA approved design, it must be checked in accordance with the FAA approved data.

But again, we are dumbing down our engineering documentation to cater to the lowest common denominator.  I just don't like it.

RE: Acceptable to have assembly drawing an exploded view?

If photographic documentation is allowable by the standards, I find it hard to believe that exploded assemblies (without any orthographic views) would be prohibited.

"Good to know you got shoes to wear when you find the floor." - Robert Hunter
 

RE: Acceptable to have assembly drawing an exploded view?

bf109g that's my line of though, have separate work instructions/travellors whatever you call them with most of the exploded views, photos etc.  

However, in the commercial world especially, there's the assumption that extra documents mean extra work/cost and money can be saved by combining them in a single document.  I'm not sure that's always completely true, but I'm getting tired of arguing the case.  Hence I'm about to put a bunch of photos, that depict things already shown in a true drawing view as well as step by step instructions (in contravention of 14.5) on what was a nice clear assembly drawing.

ewh, I'm not sure anyone has stated exploded views are prohibited.  The contention as I understand it is whether they can be used by themselves.

KENAT,

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RE: Acceptable to have assembly drawing an exploded view?

That is why I qualified my post with "(without any orthographic views)".  I think we've already established that thay are allowable in some contexts.

"Good to know you got shoes to wear when you find the floor." - Robert Hunter
 

RE: Acceptable to have assembly drawing an exploded view?

Photographs may be showing the assembled state, which meets the requirements of ASME Y14.24, 4.1.3, I still don't think an exploded view meets those requirements.

KENAT,

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RE: Acceptable to have assembly drawing an exploded view?

I wasn't trying to infer a connection between assemblies and photos, just the fact that such liberal documentation methods are allowable in some situations but not others.

"Good to know you got shoes to wear when you find the floor." - Robert Hunter
 

RE: Acceptable to have assembly drawing an exploded view?

(OP)
How does one put tolerances on a photograph or exploded view?

Man, I didn't think I'd open up a can of worms like this...

RE: Acceptable to have assembly drawing an exploded view?

A Sharpie?
Time to break out those poles! fish2

"Good to know you got shoes to wear when you find the floor." - Robert Hunter
 

RE: Acceptable to have assembly drawing an exploded view?

Dimensions on assembly drawings, that's crazy talk.

No,no, no, no, no - we want vague un inspectable requirements like 'approximately centered as shown in the beutiful photographs'.

Of course, as the OP seems open to veering off topic, a lot of this issue is related to de-skilling the shop floor.

Most on the shop floor can't read an engineering drawing.  I thought this was where production/manufacturing/industrial engineers came in and filled the void by translating Design's requirements into the required steps to achieve those requirements.  Be this as a traveller that follows the job, work instructions, fancy 3D CAD animations, cartoons, placards, specific task oriented workstations & training...  Trouble seems to be, managers want to get rid of the skilled labour, without getting enough/any manufacturing engineers that can translate the drawings.  Hence you end up with these abortions of so called assembly drawings.

[Sorry, I'm in a bad mood about that drawing still]

KENAT,

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RE: Acceptable to have assembly drawing an exploded view?

Which drawing was that?

"Good to know you got shoes to wear when you find the floor." - Robert Hunter
 

RE: Acceptable to have assembly drawing an exploded view?

(OP)
Heck, some of our machinists can't read a drawing, as evidenced by some late night panic calls to yours truly.  

You're right, there is a definite movement afoot to clear the decks of all skilled workers on the shop floor.  I won't be politically incorrect by mentioning that I need an interpreter to converse with some workers, but there I went and did it.

RE: Acceptable to have assembly drawing an exploded view?

My 2 Mar 09 15:01 post.

It wasn't even my @#$%#$%@# drawing in the first place.  It was a pile of #$%#$% I picked up from an intern and made legibile.  Then every other day they come up with some other requirement they forgot to specify that needs adding, it's now culminated in so many extra notes and photo's that it really needs an assembly procedure not just a drawing, but they don't want to do that, even when I offered to do it.  They even made me take off the nice clear dimension;-(.  I'm off to complain ineffectually to my boss about it.

KENAT,

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RE: Acceptable to have assembly drawing an exploded view?

Sorry, I missed that... Oh man, I feel for you.  I really hate it when I'm asked to be a cartoonist.  That's just about the worse insult you can give a good drafter/designer.

"Good to know you got shoes to wear when you find the floor." - Robert Hunter
 

RE: Acceptable to have assembly drawing an exploded view?

bf109g,

   As a general rule, exploded views are unsuitable for dimensions.  An orthogonal view is much more suitable for this purpose.  If it reaches the shop at 1:1 scale, it can be used as an assembly fixture.

   Parts that attach solidly together do not require assembly dimensions.  Parts that will be adjusted in some later process should be assembled to a nominal dimension, plus/minus some tolerance.

   Drawings are a means of communication.  You apply the views that communicate the required information.  Systematically apply exploded views is just as limited as not ever applying exploded views.

               JHG

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