Weldment Drawings - Common Practice vs Standards

[Anonymous]

We all have seen the filled cross-section of the weld
bead and the so-called caterpiller that graphically represents the surface melt
pattern characteristic of the weaving pettern used by the welder but I can find
no reference to these common practices in any published international standards.
All of the standards to which I have access indicate no
representation at all of the physical weld in the
drawing.

If any of you have any source material that indicates
otherwise - please get in touch with me as soon as possible.

I'm not looking to remove the ability of the end
treatment or caterpiller drawing view representations but I want to know what
the "rules" are (if in fact there are any at all regarding these commonly used
drawing symbologies).

Thanks!

[JohnPonikvar]

The only reference I have seen is by "Jenson". Seems to be the defacto text book. It pretty much describes what you said in the body of your post.


JP

[afettig]

I have made thousands of weldment drawings and have never used a "caterpillar" symbol. (I think they are distracting and unnecessary.)



Anthony Fettig
Manager of Engineering
Entrust Tool and Design Co., Inc.

[Anonymous]

The caterpillar or shaded treatment of welds
has been "artistic license".  Mostly in the past (read drawing board
and T square era), technical illustrators applied that for manuals and
catalogs.

--
Hal Gwin
Mechanical
Designer
Xenogen

P.S.  yes I dated myself, I have lots of gray
but have lost my pencil bump.  😛

[Anonymous]

This is a good point. For many years we have had a document called an
assembly instruction. These never met any standards except the ones we
established. The point here is that we hired artists with drafting
experience to do them. We have thousands of them in the system and the
overriding goal was to produce documentation which could be read by shop
assembly personnel, not blue print readers, machinists or engineers.
These would be read by buyers and planners etc. as well.

As to standard documentation, I usually referred to old Airco and Linde
books ( I mean really old).

Drawing rule number 1 provide all necessary views and information to
create the part(s) without making a phone call. Rule number 2, provide
clarity where ever possible.

PS: Pencil bump gone, replaced with wrist problems.

Hal Gwin wrote:

> The caterpillar or shaded treatment of welds has been "artistic
> license". Mostly in the past (read drawing board and T square era),
> technical illustrators applied that for manuals and catalogs.
>
> --
> Hal Gwin
> Mechanical Designer
> Xenogen
>
> P.S. yes I dated myself, I have lots of gray but have lost my pencil
> bump. 😛
>

[Anonymous]

Having just reviewed Chapter 18 of Engineering
Drawing and Design, 5th Edition by Cecil Jensen & Jay D. Hesel, only Welding
Symbols and Weld Symbols are used.  In the one or two examples showing
caterpillars, they are used ONLY in pictorial representations of welds. 
They are NOT used in engineering drawings.  And that is the reason you
haven't been able to find documentation about using caterpillars in engineering
drawings.  I thought it seemed odd to be able to add caterpillars to idw
files!

Ideally,  Inventor at some point in
time be able to both physically and symbolically portrait all weld symbols and
welding symbols.

style="PADDING-RIGHT: 0px; PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: #000000 2px solid; MARGIN-RIGHT: 0px">

"Gary R Smith (Autodesk)" <
href="mailto:gary.r.smith@autodesk.com">gary.r.smith@autodesk.com>
wrote in message
href="news:760209618C2A1D019B0F6C335FD9CF86@in.WebX.maYIadrTaRb">news:760209618C2A1D019B0F6C335FD......

We all have seen the filled cross-section of the
weld bead and the so-called caterpiller that graphically represents the
surface melt pattern characteristic of the weaving pettern used by the welder
but I can find no reference to these common practices in any published
international standards. All of the standards to which I have access indicate
no representation at all of the physical weld in the
drawing.

If any of you have any source material that
indicates otherwise - please get in touch with me as soon as
possible.

I'm not looking to remove the ability of the end
treatment or caterpiller drawing view representations but I want to know what
the "rules" are (if in fact there are any at all regarding these commonly used
drawing symbologies).

Thanks!

[Anonymous]

If you are responsible for the catapillar
programming, I have a request--

Picture a 1/4" square plate with a 2" x 9/32"
slot.  Picture another 1/4" plate shaped like a "T" where the vertical leg
is made to pass perpendicularly through the slot until the T's cross bar rests
on the first plate.  Now I want place a fillet weld along both sides of the
T's crossbar.  When I create a catapillar or a fillet weld, it stops at the
slot.  I can't get IV to generated this weld symbolically nor graphically I
think because of the 1/32 difference between the slot and the plate
thickness.

Just a request.

[Anonymous]

> PS: Pencil bump gone, replaced with wrist problems.

Still have pencil bump, and the wrist problems to accompany.

[Anonymous]

Thanks Jim!

style="PADDING-RIGHT: 0px; PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: #000000 2px solid; MARGIN-RIGHT: 0px">

Having just reviewed Chapter 18 of Engineering
Drawing and Design, 5th Edition by Cecil Jensen

[tbrack]

I think the main reason welds weren't physically shown in stadards it that it took too long (in the standards makers opinion) to draw them in by hand, especially with odd geometry that would require a third view to generate correctly. That argument still held with 'plain' CAD. Most solid modelers either couldn't create 'real' welds or was so painful in the process, that the vote was still against showing weld beads.

In weld drawings I can understand the argument that the weld symbols should be enough. But the grand assumption here is that every welder is an AWS pro with 10+ years experience and understands every symbol in the book. But since this country has seemingly dedicated itself to phasing out all manufacturing jobs, finding such people is getting to be next to impossible. So giving the new guys a fighting chance with a real representation of a weld (in addition to all the symbols) is a very good idea, IMHO.

I've always wondered what companies who use only weld symbols do when they submit an approval drawing to their customers. Do they leave the symbols on so they can be second guessed or saddled with extra unneeded weld specs, or do they just take them all off and tell the customer to assume that any parts in contact with each other are welded?

So if you can add real welds for real, messy geometry: please do so.

[Anonymous]

I agree 100% !!

style="PADDING-RIGHT: 0px; PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: #000000 2px solid; MARGIN-RIGHT: 0px">I
think the main reason welds weren't physically shown in stadards it that it
took too long

[Anonymous]

You sir, are welcome! I'm glad to have helped.