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Assembly Drawing, LEVEL 3
5

Assembly Drawing, LEVEL 3

Assembly Drawing, LEVEL 3

(OP)
I have a question on Level 3 assembly drawings.  The company I work for is really not into creating level 3 drawings.  So with a contract with a military customer, the customer request level 3 drawings.

The company I work for typically does their assembly drawings as isometric explosion view.  

My question, does level 3 drawings prohibit the use of isometric explosion views to depict an acurate assembly type drawing.  I do not think so, but not sure if there is a spec that specifies this.

Thanks.

RE: Assembly Drawing, LEVEL 3

You can use exploded views as additional to the other views, but not alone.

Chris
Systems Analyst, I.S.
SolidWorks 06 4.1/PDMWorks 06
AutoCAD 06
ctopher's home (updated 10-27-06)

RE: Assembly Drawing, LEVEL 3

The specs are now found in the appendix if ASME Y14.100.  The appendix are a copy of what was MIL-STD-100 and MIL-DTL-31000.

--Scott

http://wertel.eng.pro

RE: Assembly Drawing, LEVEL 3

(OP)
Thanks ctopher and swertel.....I knew you could use it, but not alone, especially if this is a large assembly with many sub-assemblies fastened to it....Hard to explain to people who are not use to seeing that.  ONLY some kind of spec will prove a point.

RE: Assembly Drawing, LEVEL 3

An exploded view doesn't actually show the part assembled and as such shouldn't be used as the only view(s).  It's kind of in 14.5 (or maybe a related document, can't remember) but you have to want to understand it if you catch my drift.

I tried looking in past threads as I thought the reference was there but couldn't find it, did come across this.

thread1103-157857

RE: Assembly Drawing, LEVEL 3

(OP)
Also, swertel, you know of a site where I could look thru ASME Y14.100?  This company will not spend the money to get a copy.
Thanks

RE: Assembly Drawing, LEVEL 3

You can't look through ASME docs without purchasing them.
That's too bad. Every eng company should have a copy.

Chris
Systems Analyst, I.S.
SolidWorks 06 4.1/PDMWorks 06
AutoCAD 06
ctopher's home (updated 10-27-06)

RE: Assembly Drawing, LEVEL 3

(OP)
This company ONLY has short version, and unfortunately ASME Y14.100, it doesn't....

RE: Assembly Drawing, LEVEL 3

(OP)
KENAT, read that forum...wow.  But in a nut shell, seems depending on the customer requirement, so goes the drawings.  USAF, wants level 3....to me, ONLY an ISOMETRIC assembly does not give them what they WANT, or paid for.

Thanks

RE: Assembly Drawing, LEVEL 3

I've never worked level 3 as such (my defense work was back in the UK) but I'd doubt if just ISO would do them, especially just an exploded ISO.

Y14.24M-1989 (our current edition has gone walk-about) says at Requirements paragraph 4.3d

[quote]depiction of the items in the assembly relationship, using sufficient detail for identification and orientation of the items.  Details of a subordinate assembly are not normally repeated on the assembly drawing of a higher order.[quote\]

I think is says the same in the newer version.

So certainly I would expect just an exploded iso not to be acceptable, it doesn’t show items in the assembly relationship and doesn’t rigidly define the orientation of the items.

I know a man who has checked level 3, I'll see if I can get him to chip in.

Ken

RE: Assembly Drawing, LEVEL 3

Oops, make that

............

Quote:

depiction of the items in the assembly relationship, using sufficient detail for identification and orientation of the items.  Details of a subordinate assembly are not normally repeated on the assembly drawing of a higher order.

RE: Assembly Drawing, LEVEL 3

(OP)
Kenat, thanks for the info...

RE: Assembly Drawing, LEVEL 3

designmr,

The appendix of ASME Y14.100 is really a copy of MIL-STD-100 and MIL-DTL-31000.  You can view the specs at http://assist.daps.dla.mil/online/start/

Just click on quicksearch and type in 100 and 31000 in the document number field.

You'll see that MIL-STD-100 has been canceled and superseeded by the ASME specs, but you still have access to viewing Revision G.
MIL-DTL-31000 is still current at Revision C.

--Scott

http://wertel.eng.pro

RE: Assembly Drawing, LEVEL 3

(OP)
Thanks, swertel

RE: Assembly Drawing, LEVEL 3

Spoke to my colleague and he mentioned that one of the main things to remember was that a level 3 drawing pack was of such a standard, and complete enough that it could be given to any competent engineering company and they could produce the equipment.  As such it can reference no proprietary info, it must all be fully detailed SCD, VCD etc.  This is to allow competitive tendering and/or second sourcing to increase production rate.

That may not directly affect the question you asked but the following may to some extent.

Usually the government will effectively own the drawing pack at the end of it so it has to fully meet all their standards.  If this is the case then you are effectively being paid for the drawing pack as well as any hardware you may end up delivering.  Contract should make this clear.

At my last place in the UK we had to frequently remind management & production of this.  They’d want us to designate hardware etc by its MRP codes or leave something out of drawings to give us a competitive edge or put more unnecessary information on drawings to make their jobs easier.  Any of this would have contravened the equivalent to level 3.


RE: Assembly Drawing, LEVEL 3

(OP)
KENAT....I worked with an aerospace company for almost 19 years way BACK..Your right, the customer OWNS the drawings.  And that all INFO, should be on the drawings.  

This company I work for now, the owner is under the REALLY old school of "you can drawing it on a napkin and the shop will understand it".....Which is correct, maybe our shop, because they can come in and ask question, but other companies may not.

Thanks again

RE: Assembly Drawing, LEVEL 3

KENAT,
That is also what I understand level 3 to mean - the equipment could be made by any competent engineering company in the world.

RE: Assembly Drawing, LEVEL 3

Yes. The drawings to be drawn so that if your company goes out of business, the product can be built anywhere.

Chris
Systems Analyst, I.S.
SolidWorks 06 4.1/PDMWorks 06
AutoCAD 06
ctopher's home (updated 10-27-06)

RE: Assembly Drawing, LEVEL 3

designmr: As my colleague KENAT and others have eluded to, level 3 Production Drawing packages were defined in DOD-D-1000B, which has been superseded by MIL-DTL-31000, and As I recall, the level 3 verbage is not in MIL DTL-31000 that made it clear that your drawing package had to be so complete that "a competent manufacturer could build the product, meet physical and performance characteristics, and maintain quality control of the product without additional data or recourse to the original design activity."
 I would pay close attention to your contract verbage regarding level 3. This could reject your entire design package if not followed.
  Regarding the exploded view issue, better to show the assembled product as primary view, then use details or exploded views to callout parts.  

RE: Assembly Drawing, LEVEL 3

(OP)
CheckerRon,  I reading thru a MIL-DTL-31000C, right now....Amazing the contract people are not even sure what a Level 3 drawing should actually look like...Seem they are going to try and push a explode isometric assy drawing on them......I don't think that is going to work.  After a year (I have been with this company only 5 month) of people working on this program, their spending these last couple months trying to put a level 3 drawing package together....what a mess.

Thanks

RE: Assembly Drawing, LEVEL 3

I suggest getting a copy of the contract for your files and read through it. Don't rely on purchasing, contracts or sales to do engineering work.

Chris
Systems Analyst, I.S.
SolidWorks 06 4.1/PDMWorks 06
AutoCAD 06
ctopher's home (updated 10-27-06)

RE: Assembly Drawing, LEVEL 3

As a minimum I would expect that the level 3 would require all relevant ASME/ANSI drawing standards (probably by calling up Y14.100) to be followed.

By my understanding of the section of 14.24 I put a few posts ago, an exploded iso assy view alone would not be adequate.

You may be lucky (if that's the right term).  Some branches of the service are apparently stricter than others from what a colleague told me, with Navy being the strictest.  My colleague has worked on contracts where the drawings were rejected and the program delayed accordingly.

I'd read that contract carefully and ask the office giving the contract for clarification if necessary, I doubt if trying to force them to take something will work out for you (by which I mean your company not you personally).

Ctopher - thanks I'd forgotten that 3rd reason.

RE: Assembly Drawing, LEVEL 3

Have you been able to find a copy of DOD-D-1000?  I am lucky to have made a personal hard copy long ago, but have yet to be able to find it online anywhere.

Assist doesn't have it.  IHS doesn't have it.  GlobalSpec doesn't have it.

--Scott

http://wertel.eng.pro

RE: Assembly Drawing, LEVEL 3

(OP)
Swertel...thanks, yes I found a DOD-D-1000B, here at work...plus download Mil-DTL-31000C off the internet...

thanks

RE: Assembly Drawing, LEVEL 3

To DESIGNMR: LAST WORD: I found my copy of Mil-DTL-31000 Rev. C, and Paragraph 3.6.2 TDP Elements covers what used to be levels 1, 2 and 3.
¶ 3.6.2.1 is equivalent to DoD-D-1000 Level 1,
¶ 3.6.2.2 equivalent to Level 2,
 (and for your application)
¶ 3.6.2.3 covers the former Level 3 requirements.
 The verbage is quite similar to the old DoD-D-1000, level 3, thus the strict requirements ARE still there.

RE: Assembly Drawing, LEVEL 3

Thanks, pong1.  I've been trying to find an online source for DOD-D-1000 in case I ever lost my hard copy.

--Scott

http://wertel.eng.pro

RE: Assembly Drawing, LEVEL 3

designmr

Did you ever get to the bottom of this?  I'd be interested to find out what happened/how it went.

RE: Assembly Drawing, LEVEL 3

(OP)
Thanks for asking, basically since this company has spent months feeling drawings are NOT need (though the customer is expecting Level 3 drawings).  They decided to push thru isometric type drawings, and hope the customer will find them satisfactory.  I believe it is a way to buy time, myself.   

An isometric drawing does not tell someone how to build a assembly (unless the assembly has 2 or three parts) maybe.

Crazy company this one.....

RE: Assembly Drawing, LEVEL 3

You may under some circumstances get away with just isos, but just exploded isos are another matter.  Contravenes the standards.....

If they're trying to buy time does that mean some one is beavering away on proper level 3 drawings?  I'm guessing not.

Good luck

RE: Assembly Drawing, LEVEL 3

(OP)
Since time is unfortunately not on our time. I'm trying to do as many proper level 3 assembly drawings, but in this group, they are use to do ISOMETRIC drawings...And you hit it, they are EXPLODED ISOMETRIC drawings, which does make it worse.  Which shows one set of fasteners set, NO detail of how the fasteners are arranged....

Can you imagine working at a company that the OWNER, would rather have the shop make a product, then have engineering go after and try and capture the design???  This main job, was NOT captured properly (especially with TONS of last minute changes), now the UNIT is GONE, and drawings still need to be created...OUCH...

Thanks again...

RE: Assembly Drawing, LEVEL 3

Quote:

Can you imagine working at a company that the OWNER, would rather have the shop make a product, then have engineering go after and try and capture the design???

Imagine it, I live it day to day at my current employer.  

RE: Assembly Drawing, LEVEL 3

(OP)
TOTAL craziness......no wondering the shop keeps complaining the drawing package are ALWAYS WRONG with errors.

I've only been here 6 month, so I just DON'T GET IT....

I guess scrape parts and re-work is fine.....

Thanks, Kenat

RE: Assembly Drawing, LEVEL 3

designmr so did the customer take them?

RE: Assembly Drawing, LEVEL 3

(OP)
Hey Kenat....seems this company has a GREAT sales team.  Because so far the customer has been looking at exploded isometric ONLY assembly drawings, go figure.  

To me they are NOT even close to what a level 3 drawing should be.  Oh well.

Thanks for ask though.

RE: Assembly Drawing, LEVEL 3

(OP)
I need a NEW JOB......(and yes I am LOOKING......)

RE: Assembly Drawing, LEVEL 3

I just asked because the exploded view thing came up again here.  My manager sent out a memo based on an email I'd sent which explains our interpretation of what the standards say.

Quote:

The following memo is a result of a meeting held between YYYY and I.  The anticipated result of this memo is to satisfy the requirements of the designated commercial engineering design standard (ASME) we are following and the needs of engineering.

The wording in the DRM on exploded views, based on the standard is:

"On assembly drawings exploded views shall not be the primary view, as they do not show components in the assembled state (ASME Y14.24 section 4.1.3 (d)).  As such exploded views shall be the least preferred method for showing assemblies on drawings and shall only be used when they offer significant advantages over other types of views and then only in addition to suitable orthographic views."

For a legacy drawing using only exploded views, undergoing a relatively minor revision such that a complete redraw is not justifiable then keeping the exploded views offers a "significant advantage" and is permissible.  However, it may be necessary for orthographic views showing the item fully assembled to be added, this should take only a few mouse clicks in most cases.  Please let me know if you have any questions.

Regards!

XXXX

RE: Assembly Drawing, LEVEL 3

(OP)
Makes all the sense in the world....Unfortunately we know that making good readable assembly drawings take time ($$$$$$), this company does NOT want to spend the money, so isometric assembly are the way it will be done.  
I am surprised the customer (military) will except them...Guess things maybe have changed????

Thanks again,

RE: Assembly Drawing, LEVEL 3

designmr-

On one of your posts you said: 'An isometric drawing does not tell someone how to build a assembly...'.

Don't fall into the mindset that a drawing is a manufacturing document.  It is first and foremost an engineering document and, as such, should describe only the end-item requirements.  It should not describe how to get from point A to point B (there are exceptions for special processes not widely practiced in similar manufacturers).

People add reams of notes saying how to do things (I call these instructions) ala "INSERT SCREW, FIND NO 4, INTO HOLE.  ENGAGE NUT ON SCREW."  Sometimes people do it because they don't know any better.  Sometimes they do it because the manufacturing function lacks the people to write work instructions or because Mgmt tells them to do it.

To tell a manufacturer how to get from A to B is essentially telling him how to do his job: it ties his hands, stifles his ingenuity and creativity, and drives up costs.  Not to mention that the drawing becomes a living, breathing, heavy creature that is constantly undergoing change and eating up engineering hours!

Whew,...,sorry but I've fought this battle with so many for so long it aint funny!





Tunalover

RE: Assembly Drawing, LEVEL 3

(OP)
Good points TunaLover, so do you think that Level 3 drawings are ok as just an Isometric exploded view and a parts list?  I'm asking because that is the way the company I works for is desplaying their level 3 assembly drawings.

thanks

RE: Assembly Drawing, LEVEL 3

designmr-
I wouldn't because an exploded isometric view alone does not depict the end-item.  I would use an exploded view only for reference (non-binding, doesn't count).  Just place the note REFERENCE in the view caption.
Tuna



Tunalover

RE: Assembly Drawing, LEVEL 3

I agree with Tunalover.

Chris
SolidWorks 06 5.1/PDMWorks 06
AutoCAD 06
ctopher's home (updated 01-18-07)

RE: Assembly Drawing, LEVEL 3

That's exactly what I think.  Fine for reference, ocasionally I'll include it however do the 'cost benefit analysis".  Not just for making it in the first place but for maintaining it at the next rev, this is where our CAD sometimes falls down.

And from my understanding of the standard, certainly not just an exploded iso.

I'm also with tuna on generally keeping instructions off drawings.  They should normally be phrased as requirements or in a separate work instruction created by manufacturing.

RE: Assembly Drawing, LEVEL 3

(OP)
Well we ALL agree, but this company I work for, is ONLY putting out Exploded isometric assembly drawings as Level 3 to our military customers.  

On the small assemblies I try and show views and details of assemblied items (hardware and such), though I am told quit spending time on those type of drawings.

Maybe they are trying to buy time since we ran out of time by months on getting the customer a good package like the customer wanted and were expecting.  We all know that a level 3 package, should be understandable by anyone else to manufacture, not just the company who initially designed and build it.

Like I said before the owner of this company (who calls the shots on EVERYTHING), has always thought drawings are a waste of time.....

Thanks again everyone.

RE: Assembly Drawing, LEVEL 3

designmr-
It goes to show you how many people in this business (especially management) think they know as much (or more) than the designer/ME.  I call this "confident cluelessness."

Does the contract state that the product and drawing package will undergo a Physical Configuration Audit (PCA).  If so then tell your boss (the owner) that if the auditor is anything more than a rubber stamp he'll end up rethinking his expertise on engineering documentation over six figures worth of drafting hours.



Tunalover

RE: Assembly Drawing, LEVEL 3

(OP)
Thanks, Tunalover, but this owner always throws out, he has over 50 years experience in the business so NOBODY tell him he is wrong (unless they want to be let go....pretty sad.

RE: Assembly Drawing, LEVEL 3

You have my condolences.  I'd seek other, less dictatorial employment.

Tunalover

RE: Assembly Drawing, LEVEL 3

I worked for a company like that once ... once.

Chris
SolidWorks 06 5.1/PDMWorks 06
AutoCAD 06
ctopher's home (updated 01-18-07)

RE: Assembly Drawing, LEVEL 3

(OP)
Tunalover and Ctopher....I am looking (this place is stuck in the past).....And soon I can say "I worked for a company like that once...once"

RE: Assembly Drawing, LEVEL 3

designmr, I wouldn't get caught up with

Quote:

(this place is stuck in the past)...

My place which deals with nanotechnology is arguably stuck in the future.  However we encounter similar problems.

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