Help with a 1960's era drawing call out...

I've been working on drawings since the mid 1980's and I haven't come
across this one yet...

Anyone ever see a call out on a print like the one below? This print is
from the '60 and it points to a few surfaces and a bore. I'm thinking
it might be some kind of burr call-out? The mating part calls out the
same symbol on the mating shaft and face. All the same surfaces
indicated by this also have the normal 32 surface finish call out, so
it's not that.


___B___ ___15___
/ \/\/
/
| /
|/__

I tried searching the web, but came up short...any ideas?

Thanks

IYM

 

Anybody?

 

I have a call in to the customer...It may be some internal spec used by
them back then...

I'll post when I find out...5 engineers here never saw it before and the
VP of Quality Control who was working here before I was born, and that's
sharper than most 25 year olds has never seen it either. I feel beter
knowing at least it's not me! lol

 

No - Definatly a B...Print is clear, just old. Sorry about the text
look of it, but I tried (lol) the bottom is supposed to be an arrow
head, not a corner it's pointing to. It's supposed to be one straight
unbroken line with a kind of "w" in the line and it actually points to 3
surfaces and a bore. Interestingly, the mating part has the same symbol
on the mating surfaces and features. Customer is still looking into it
and will post the reply when I find out.

Thanks.

 

Probably "Break edges" .015 (chamfer).
Anything in the change or general notes?

 

Just FYI - I got confirmation back from the customer today....They had
been looking at it, checking archives ect. and finally came up with....

<drum-roll>

"We have no freakin' idea what the hell that is!" LOL and the solution
was to give us a waiver saying to ignore that callout...

There is always a first for everything.... lol

 

IYM wrote:

(...)

You passed the test!

That looks like a 'Van Halen Callout'
http://www.snopes.com/music/artists/vanhalen.asp

"By far the most notorious of these whimsical requests is the legend that
Van Halen's standard concert contract called for them to be provided with
a bowl of M&Ms backstage, but with provision that all the brown candies
must be removed. The presence of even a single brown M&M in that bowl,
rumor had it, was sufficient legal cause for Van Halen to peremptorily
cancel a scheduled appearance without advance notice (and usually an
excuse for them to go on a destructive rampage as well).

The legendary "no brown M&Ms" contract clause was indeed real, but the
purported motivation for it was not. The M&Ms provision was included in
Van Halen's contracts not as an act of caprice, but because it served a
practical purpose: to provide an easy way of determining whether the
technical specifications of the contract had been thoroughly read
(and complied with)."


--Winston

 

Had to snip out comp.cad.pro-engineer because of a crosspost limit.

Well, even with the free pass I still wouldn't "just" ignore that
callout without thinking it through first. Look at the names in the
title box, and see if you can track down any of the original engineers
or designers of the device - ask them what the heck it means.

Get the details of what this part is supposed to do and how it goes
together, and have their engineers think it through as if they were
designing it new. If it makes sense to do a radius break on that
corner, you want to do it - AIUI, a knife-edge corner is a real good
place to start a crack, where a nice radius edge spreads the stresses
around _just_ enough to keep it from starting...

And if this is for aircraft or medical use, you'll be in BIG trouble
not following the print, especially when it fails and kills someone -
The FAA or the FDA is going to want to know the exact parentage of
that part that failed. And they'll be looking for blood.

Good theory, it's possible - but more likely that the origin of the
callout is simply lost in the mists of time.

"Never ascribe to Malice what can easily be written off as Stupidity."

If they walk in and see Brown M&M's in the bowl, that is a Red Flag
to make sure the promoter has the right risers on the stage, the right
microphones and band amps, the right mix board and house sound system,
and all the other myrtiad details are complete and correct.

And if they aren't, THEN they have an perfectly valid reason to
storm out and cancel the gig - The band usally arrives the morning of
the show or at best a day ahead, and there is simply no time to fix it
if the Promoter has deliberately not followed the contract.

There are many unscrupulous promoters out there who will cut corners
ruthlessly to make more money from staging the concert, to the point
where the band sounds like crap, looks like crap and the reviewers
can't help but notrice and tell the world that the band has "lost
their groove thang"... And guess whose reputation takes a hit? (Hint:
It 's the band, NOT the promoter.)

If the band contract calls out for specific models of Sennheiser or
Blue or other specialty vocal mikes that capture their voices best,
and they walk in and see the Promoter has rented them a row of beat-up
old Shure 57's for primary singers and a bunch of Shotguns for the
backup singers, that is going to be trouble. Yes, they will "work",
but they are not the best fit for many voices and will make you sound
horrid - they will amplify any faults in your voice.

In the same spirit, they will cut corners on the speaker stacks, the
amps, the mixing board (an old Nady instead of the big Yamaha the
specs called for) the lighting, the effects, the Stage Security and
controlling the Access Passes...

--<< Bruce >>--

 

Have to try the nursing home - lol...<joke> Some of the other
components calling out the same symbol have a 1953 dwn date...On the
basis that the engineer/designer/draftsman were around say 30 years old
around that time, that would put them in their late 70's or 80's, well
past retirement. I don't think there is anyone there from that era
anymore. Also, the prints were acquired by our customer in the 1980's
when the original company was acquired (I believe), so the paper trail
to find someone gets a little muddy..

The problem is that all the things you mention are all on the print too.
Radius, chamfers, surface finishes are all called out. (The leader is
not pointing to edges but to surfaces.)...and besides, come on - we
would never leave a knife edge (unless otherwise specified - and even
then the guys on the shop floor would be coming in giving me crap about
that! - lol)

(BTW - for the other poster - It's a moving part - no welds whatsoever)

yup - We've been mfg aircraft and medical parts for 30 years, so we kind
of know. We don't fool around. (www.precipart.com)

 

This is a long shot, but my first reaction was that it was a callout for the
lay and direction of the finish texture. I've seen those in mold work and
sometimes on bearing surfaces, but my books don't show that one. It's
possible.

 

Nor would I.

Check the mating parts, if any. It still has to mate, right?

And to get dinged in shippping & assembly, etc.
Or even prevent assembly.

If there are even older versions of the print one might
have a note of adding that callout. Might.

 

IIRC The /\/ on the label leader indicates an edge break
& R indicates radius while no R indicates a chamfer break.
But don't hold me to it.

 

That should be on an assembly, not detail, drawing I'd think.
Plus I checked some weld symbod charts (but no doubt missed many).

 

Give a copy of the print *as is* to jb to make.
Then don't do what he did.

Problem solved.

 

So? Track a few bodies down, if they are retired from the client
company their Payroll Department had better know where they are
sending the retirement checks...

Call. Or if you are close, stop by, and bring their favorite
libation... You might be pleasantly surprised how much you get when
you pick their brains.

Including "Oh, THAT part! Did they give you the print for the A
revision, or the C Revision? We had a crash and traced the failure
back to the A Revision part, we totally redesigned it in 1960."

(And then you look, and you were indeed going to make a batch of a
known bad design off the A Revision print, because someone at the
office didn't dig into the old files deep enough...)

The joys of a lack of corporate continuity - having a few old farts
hang around who remember where all the bodies are buried, and can show
the young bucks that there are /far/ better ways to get things done
than a brute-force frontal assault.

But the Accountants can't let that happen - they hire for the
project and fire as soon as it's over.

I figured you knew, but it never hurts to restate the obvious - just
in case Transient CRS happened.

--<< Bruce >>--

 

Just following up - Our customer finally found an ancient spec that
contained the information! It was their own internal spec regarding
deburring. They have three grades (A, B, & C,) from best to worse
(won't bore you with acceptance criteria for each) and the number
designates the magnification level it has to be inspected under. So my
drawing designated a "B" and had the # 15...

Thought I'd let everyone know in case they were interested....

Thanks....

IYM

 

Very interesting.
Thanks for the update.
Who would ever have guessed?

And how did they lose/forget their own internal spec?

BTW, All such prints should refer to the internal spec & it's
revision level and be included with all requests to outside vendors.
"Shop Standard"

Clearly time for a "Redrawn W/O Change" that includes the
info in an explicit manner but drops the spec & odd notation.

Is that "W/O Change"?

 

Very interesting.
Thanks for the update.
Who would ever have guessed?

And how did they lose/forget their own internal spec?

BTW, All such prints should refer to the internal spec & it's
revision level and be included with all requests to outside vendors.
"Shop Standard"

Clearly time for a "Redrawn W/O Change" that includes the
info in an explicit manner but drops the spec & odd notation.

Is that "W/O Change"?