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Picture files used on drawings

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lonsgsp

Mechanical
May 31, 2005
37
On a few occasions I have been asked to insert/embed a jpeg file onto a drawings sheet and with the exception of one time have told engineering that this is a practice I would like to stay away from for the following reasons:

1. Clarity, graphics files typically do not have the best resolution and when plotted appear dark (large amount of toner) and copies of the original are even darker

2. Cannot detail a graphics file using cad software, need to use a program like "paint" to put in leader lines and such.

3. Graphics files tend to make the file size large

We strive to follow the ASME Y14 specification series and I cannot find anything that covers this practice.

I would like to get some feedback on this practice and if it should be avoided.

Thanks
Lon
 
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"A picture is worth a thousand words"
If the picture serves to clarify the features, helps the machinist visualise the part, and prevents errors, then use it. I often add shaded isometric views when detailing more complex part drawings, and they are usually appreciated in the machine shop.
 
I think it is allowable. It may be directly addressed in Y14.4M Pictorial Drawing, but I do not have a copy available to verify this.
Y14.24M-1989 [¶] 1.4 does state that such methods "are a concern of this Standard only to the extent that the drawing satisfies its intended purpose."
I agree though that they are better avoided.

"Good to know you got shoes to wear when you find the floor." - [small]Robert Hunter[/small]
 
Also, per DOD standards, they were allowable depending on the class of drawing package required. It has been awhile since I have read those standards, and am unsure of the current requirements in this regard.
Big help, huh?

"Good to know you got shoes to wear when you find the floor." - [small]Robert Hunter[/small]
 
Thanks,

I do not have ASME Y14.4m either, but it got me thinking, and that might be dangerous.

I do have the Genum "Modern Drafting & Standards Manual" and in there it defines pictorial drawings as either isometric, trimetric or oblique drawn views.

It includes a paragraph referencing "photo inserts" and mentions, among other things, that "care should be exercised to ensure that it's reproduction qualities are unimpared when a photo copy or microfilm is produced."

I have a copy of mil-std-100g and mil-dtl-31000, but have not had the time to look through them yet.

Just trying to stay away from the slippery slope of doing this on a regular basis for the reasons mentioned in my original post.

Thanks again,

Lon
 
Being based on accepted standards, the Genium manual is a pretty safe bet as far as what is permitted, and the fact that they have included that caution is a good indication that such methods are indeed allowable.
If it can be interpreted in more than one way, or not allow for complete definition, such a method should be rejected. The key is that such methods have to satisfy the intent of the drawing.

"Good to know you got shoes to wear when you find the floor." - [small]Robert Hunter[/small]
 
I have seen this done on assembly drawings and have seen some of the problems you describe about printing and copying. I have not seen it on part drawings.

Sometimes the compromise is to trace over the picture and create a line drawing.
 
Far better to get a dumb solid (if you don't have access to the native cad file) and annotate from there. You can use rendered, contour or wireframe representations as best suited then. Assembly drawings, however, are the exception that I see value in. By including graphics of what the user will actually see (including surroundings within the work envelope), the output is far more useful. Of course at that point, most companies (with technical writers) will pull the CAD assembly into a documentation package and supplement the cad with photographs and such rather than working strictly in CAD.

Jim Sykes, P.Eng, GDTP-S
Profile Services TecEase, Inc.
 
I've been forced to do it a few times. Generally when folks want me to do it I've been able to more clearly illustrate whatever the point is using a more conventional line drawing view with appropriate stylized annotations etc.

That said, for all but the simplest assemblies we often create detailed assembly instructions where we will often use a lot of photographs. However, even here line drawings often end up being clearer.

Posting guidelines faq731-376 (probably not aimed specifically at you)
What is Engineering anyway: faq1088-1484
 
'Anything that helps the floor make the part' - whether it's called for in standards or not.

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Depends...
In many industries, engineering drives manufacturing, and full documentation per applicable standards is required whether by company mandate or governmental.
Other industries allow manufacturing to drive engineering, which leads to an extensive "tribal knowledge" type of documentation.
I much prefer the former.

"Good to know you got shoes to wear when you find the floor." - [small]Robert Hunter[/small]
 
ewh,

I definitely agree - with your first point.

The 'tribal knowledge,' though does get the part made right. I don't know - after 20 more years experience maybe I can educate manufacturing, bit by bit, and get things the way they should be.
 
Good luck!

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