For Discussion: Should SCALE be in a drawings titleblock?

[Lohbauer]

Happy Friday,

This is more of an academic discussion starter thana problem. We are looking at updating our engineering formats and the question of whether to eliminate the SCALE field came up. Given the approaching model-onlystate of ASME Y14.41-2003, is the information necessary to have in a drawing?

Have at it.

Thanks,
WindchillAdministrator

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[StephenW]

As far as I know, ASME Y14.100 still says the SCALE SHALL BE INDICATED ON THE DRAWING. I haven't looked lately to see if they have updated. It may have been updated several times since I looked though.

Y14.41 pertains to model based definition and not drawings so it's not really the same. From my perspective, Y14.41 is decades away.

Of course this is my opinion so it shouldn't be construed as my employers opinion.

[wfalco]

I honestly see no reason for using scale. Keep in mind I was on the
board. Back then - I'd say yes. Now....I don't see the point.

[BenLoosli]

My complaint with the scale being on the drawing is that too many times no one pays attention to what the system is scaling your views to. View scales should be, if used, something that makes sense for the drawing.

For metric dimensioned drawings we had this in our standards: 1:1, 1:2, 1:4, 1:5, 1:10, 1:20, 1:40, 2:1, 4:1, 5:1, 10:1, 20:1, 40:1
For English dimensioned drawings, adjust accordingly to multiples of 2, so 8, 16, 32 and 64 instead of 5, 10,20,40.

I have seen many drawings with scales like 3:50, 7:100, etc. You can’t measure them and convert to a valid size, anyway. Plus our drawings all say “Do Not Scale Drawing”.

[Lohbauer]

This what I hoped for, people smarter than me chiming in.

Yes, it is absolutely true that scale is specified in these specs. But should they? I work with both the manufacturing floor, and an old school tool shop that is old school in the best sense of the word. The issue becomes what to do in situations where there is a missing dimension and a machinist with a scale answers the question on their own?

Thanks
Bob

[BillChapman]

If they are that old school, they could just measure any dimension on the print and figure out what scale is being used. Seems crazy in this day and age that this is still going on and they are not interrogating an electronic file to get this information.

Bill Chapman
Email: -<">mailto:->
Tel: 708-496-3100 | Cell: 708-205-5705

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[dgschaefer]

I'd say absolutely. If I'm looking at a drawing, I want to know what scale these views are. While it's never appropriate to make design decisions based on a measurement from a drawing, if you need to know roughly how big a feature is, measuring the drawing is a handy way to figure this out. It also helps to get an idea how big the part in question is. "Oh, wait, this drawing is 5X (¼) scale, this thing is tiny (enormous)!"

Of course, scale information is useless these days of being able to print on any size paper without also including the sheet or format size.

We had a vendor make a sheetmetal part half size because he went off the exported drawing DXF and failed to check the scale in the title block. (This of course begs other off topic questions like should he have gone from the drawing DXF (it wasn't a flat pattern) and if we knew he was (we didn't) should he have been given a full scale version instead?)

--

[StephenW]

Scaling a drawing has absolutely no relation to the scale being shown on the drawing. Not too many places (I may be wrong) actually provide full scale prints to the manufacturing personnel.

If there is any known dimension on the drawing (or not), preferably in the same orientation as the dimension in question, I can and will scale a drawing using ratios. I’ve done it a bunch of times with varying results. It may be the only way I can get a specific dimension to make something that looks right and is not necessarily “perfect”. Vendor drawings are a good example. They usually have all the critical interface dimensions but sometimes don’t have other dimensions that I need to make a model look reasonable close to what the part will look like.

I used to say all the dimensions have to be on the drawing to be able to build something until I met a guy who explained boat/ship building to me. A lot of stuff is not dimensioned but is expected to be done “to the drawing.

[TimKnier]

Take the scale off the drawing completely. The only purpose for the drawing scale being in the title block was to tell us old time board drafters which scale to use on our old triangular drafting scales (rulers) whenever we worked on the drawings. You never want a machinist or fabricator to measure a drawing when trying to determine a missing dimension. In fact we’ve told all of our young whipper-snappers to not even worry about always using a standard scale on their drawings. Use whatever scale is needed to make the drawing views the clearest and most informative to suit the drawing size, BOM and notes.

Tim Knier
QG Product & Support Engineering
QuadTech
A Subsidiary of Quad/Graphics
Sussex, Wisconsin
414-566-7439 phone
-<">mailto:->
www.quadtechworld.com<">http://www.quadtechworld.com>

[jstone]

What a topic for a Friday! Eliminate the DETAIL SCALE by right clicking on it and ERASE.
Thanks,
jef

[StephenW]

That’s a good way to put it.

“Use whatever scale is needed to make the drawing views the clearest and most informative to suit the drawing size, BOM and notes.”

[bokm9606]

One word answer: no
On Mar 14, 2014 7:15 AM, "Williams, Steve C" <->
wrote:

> As far as I know, ASME Y14.100 still says the SCALE SHALL BE INDICATED
> ON THE DRAWING. I haven't looked lately to see if they have updated. It may
> have been updated several times since I looked though.
>
>
>
> Y14.41 pertains to model based definition and not drawings so it's not
> really the same. From my perspective, Y14.41 is decades away.
>
>
>
> Of course this is my opinion so it shouldn't be construed as my employers
> opinion.
>
>
>
> *

[cying]

Jeff,
You can’t just erase the scale, it’ll also erase the parametric name as well.

Calvin

[msteffke]

This

[TomU]

Our vendors frequently use 2D DXF and IGES files for wire burning. Not have a scale note is asking for trouble. In fact, we put a HUGE scale note right across the entire print on export to keep from getting burned (pun intended).

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[mlocascio]

I'm old school and I think that it is  dry practical to have the scale on a drawing. Of course we want to also place a note on the drawing telling our audience not to scale the drawing.



>

[mlocascio]

That's a very interesting reference to the shipbuilding industry



>

[StephenW]

I would still push the burden of "built to print" on the vendor regardless of whether an electronic file was sent. I have provide flat patterns of formed steel parts to vendors on MANY occasions. I always add the disclaimer that the flat pattern is for reference only and that the drawing is the legal document providing the requirements of the contract. There are too many variables in manufacturing that can't be taken in to account on an engineering print and especially on an electronic file. Even with in-house manufacturing, you don't always know how something will be built. The metric to English conversion is one problem that used to come up frequently.

If at all possible, I never use a dxf or iges without verifying the critical dimensions. There have been times when I have received generic product files for something that I was expecting specific product information on.

[mlocascio]

The REAL  problem lies in the new school philosophy of not fully detailing or sloppily detailing a drawing.



>

[llie]

All,

Everyone has great points, but as we move forward into the Model Based Environment there will be no measuring off of a drawing and no need for a SCALE. We should be moving forward in our industries as technology advances.


If you look at the posting from

[rreifsnyder]

I have to disagree. In our world “Shall” is an absolute requirement. If it is optional we say should or may.

I’ve been hearing about doing away with drawings since 1992, when I was told that Unigraphics II came out initially without a drafting package. I have had parts made without drawings since I started on Pro/E in 1992 but to document the design still needed drawings. While I agree with you that it is now POSSIBLE to document the solid model (although still not platform independent until STEP AP242 is widely supported), it is still not the most overall efficient method. I say that understanding that if you have control over the entire production cycle including quality, it may be more efficient but we simply aren’t there.

Rob Reifsnyder
Mechanical Design Engineer/ Producibility Engineer / Components Engineer / Pro/E SME / Pro/E Librarian
[LM_Logo_Tag_RGB_NoR_r06]

[mpeterson]

Lance,



I am all in favor of embracing model base environment, but there are plenty of other people in the process who don’t have access to this data directly and will not for a long time. There are still companies that are drawing on the board and others that are using the 2D colored electronic pencil. Many companies also export their 3D and create detail drawings in 2D. This is primarily driven by cost whether it be computers, software, training, license maintenance costs, PLM systems, servers, etc. and the list of costs go on and on. I have been with numerous companies that still do not implement PDM systems because, “well you have been doing without it up till now without it”. What about people in purchasing and all the vendors they work with? If you are buying extruded tubing are you going to insist the vendor have the software and systems to be compatible in your 3D world? Or are you going to attempt to buy per a word definition when a picture (or detail drawing) is worth a thousand words?



I also disagree with your understanding of SHALL. This isn’t a suggestion and is meant as it WILL be done. I don’t think engineers use a different dictionary.



In regard to engineers not having drafting education that is not a good situation either. Even if we go to MBE than there better be some substitute or education on how to define parts critically in regard to tolerances and GD&T. Fortunately people and organizations are working on creating and maintaining standards that apply to 3M model based systems. At a minimum engineers need to understand how to read a detail drawing since it will be a very long time before every part ever made is modeled in 3D.



Don’t get me wrong. I would love to see engineering, companies and industries embrace 3D modeling and 3D documentation, but it will be a while before the costs will allow that and until then we all still need to keep the train on the tracks and use the tools we have to communicate effectively.



Sincerely,

Mark A. Peterson

Design Engineer

Varel International

-

[JOES]

This has been a great discussion & I can’t resist joining in. OK... so those that have complete 3D capability from art to part might not need to scale documents. The rest of us still need drawings & why would we not require scale on them?

As to Engineers not getting drafting training… did they ever? Kidding! I know at one time it was part of the training. My first employer was an old school engineer & was also a talented draftsman. He told me he that he practiced is lettering 15 mins every single day when he was in school. Since then, as a mechanical designer for 20 years, I’ve yet to meet an engineer that has had much in the way of drafting training. The only exception being designers that went on to get an engineering degree.

Now days HR departments insist that these positions be filled by “mechanical engineers”, as in BSMEs. This makes backfilling positions difficult when we don’t get a single candidate that has any training or experience in actual design or drafting. Once we got lucky to get a person with two associate degrees (mechanical design & tooling design) that our HR moron claimed had the equivalent of a bachelors. Then somehow I have to convince these engineers to follow drafting standards & use our data management system. They commonly like to make some folders & handle the data management themselves with bad results every single time. Having to train them in Windchill Intralink 10.1 is no bargain either. Currently it’s an ongoing battle but one that, so far, I’ve been able to win. Quality drawings = quality products.

Regards,

Joe S.

[ptc-141274]

I also have to disagree with the word SHALL. This means an absolute requirement, both in interpreting existing specifications (ASME), and in writing our own.

While not on our internal MBE committee, in my opinion it seems we are creating the drawing (lighter version), or critical dimensions in the model. Views are created in the model that look like a drawing when the appropriate dimensions are shown, and can even be printed.

So, one could say the drawing is not really going away totally, just taking on a different form, and different way to view it.

It will take time…

Doug Pogatetz

Mechanical Design Engineer
Northrop Grumman Corporation
Rolling Meadows, Illinois 60008-1098

[mlocascio]

I agree with that too. The words we use should be important enough to matter. If we don’t want to mean one thing it should not be written down that way. That, however, does lead me into thinking about A LOT of things that “should” be done according to what is written on a piece of paper.



Michael P. Locascio

[StephenW]

ASME Y14.100 4.26.3 defines shall and should.

Shall is a manadatory requirement.
Should is nonmandatory provision


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[wfalco]

I gotta say....in the biz 30 years and "must" "shall" "to be" are
mysterious commands. Regardless at what level you'd like to invoke them
- they are still things that are be requested - and therefore do become
equal.

[BenLoosli]

Pro/E did not have a drafting module until rev 3 or 4.
UG2 had a drafting module in the original release as it was a rewrite/ported enhanced version of UG1.
UG1 in 1978 did not have an initial drafting module, but it was originally created for the manufacturing world as a graphical extension to UniAPT. I first used UniAPT in 1973 and Unigraphics didn’t come out for another 5 years. My first CAD system was Applicon 880 in the fall of 1977.

[sshannon]

There you go

[mlocascio]

Well said. There is nothing wrong with progress as long as it keeps on grounded on established and proven principles.



Michael P. Locascio