Rev A symbol on a Rev A print ??
Rev A symbol on a Rev A print ??
(OP)
Guys,
Hopefully this one will blow you away as much as it did me.
I have 2 individuals arguing over whether or not you show a Rev A symbol in the body of a Rev A print... to indicate what had changed, b/c in this example this new Rev A print was largely based on an old print. Is this making sense?
My take is that it is C-R-A-Z-Y to have any Rev A symbols. A Rev symbol is for indicating what changed going from the last Rev, and in the case of a "release-to-rev-A" situation... the print is brand new and has no history and if the engineer is trying to convey where the print came from, they should do that in the DCO, with reference documentation or a design journal, but it shouldn't be in the form of mysterious Rev symbols on a new print.
I mean seriously, have you ever seen a Rev A symbol??
We observe ASME Y14, and I've looked at 14.100, 14.3, and 14.35 and I can't find anything on this... which I think is an indication of how crazy this argument is... it's not even covered in the Y14.
Please chime in. Let me know if I'm the one who's crazy and of course BONUS POINTS if you can find where in Y14 it addresses a Rev A balloon.
Thanks,
Jack
Hopefully this one will blow you away as much as it did me.
I have 2 individuals arguing over whether or not you show a Rev A symbol in the body of a Rev A print... to indicate what had changed, b/c in this example this new Rev A print was largely based on an old print. Is this making sense?
My take is that it is C-R-A-Z-Y to have any Rev A symbols. A Rev symbol is for indicating what changed going from the last Rev, and in the case of a "release-to-rev-A" situation... the print is brand new and has no history and if the engineer is trying to convey where the print came from, they should do that in the DCO, with reference documentation or a design journal, but it shouldn't be in the form of mysterious Rev symbols on a new print.
I mean seriously, have you ever seen a Rev A symbol??
We observe ASME Y14, and I've looked at 14.100, 14.3, and 14.35 and I can't find anything on this... which I think is an indication of how crazy this argument is... it's not even covered in the Y14.
Please chime in. Let me know if I'm the one who's crazy and of course BONUS POINTS if you can find where in Y14 it addresses a Rev A balloon.
Thanks,
Jack
Jack Lapham
Engineering Systems Administrator (E20)
Leupold & Stevens, Inc.
www.leupold.com
Dell M6400 Covet
Intel Core 2 Duo T9800, 2.93GHz, 1066MHZ 6M L2 Cache
8.0GB, DDR3-1066 SDRAM, 2 DIMM
1GB nVIDIA Quadro FX 3700M (7.15.11.7950)
160GB Hard Drive 9.5MM 7200RPM FFS
W7x64 | sw-01: 55.92
SolidWorks 2010 x64 sp4.0
Enterprise PDM 2010 sp





RE: Rev A symbol on a Rev A print ??
--Scott
http://wertel.eng.pro
RE: Rev A symbol on a Rev A print ??
For what it's worth, I'm with you... if this is a new drawing and a new release, there is no revision to flag on the drawing. By definition, a new release is new. If a reference to a previous part/drawing is desired, the field of the new drawing is not the place for it, and a rev A notation there would be meaningless.
"Good to know you got shoes to wear when you find the floor." - Robert Hunter
RE: Rev A symbol on a Rev A print ??
While it's not directly relevant to the OP, it should be pointed out ASME Y14.35 (i think that's right) does allow for '-' or ' ' to be the initial release. In which case rev A would be a true rev, and so change indicators may be appropriate. See thread292-278425: Y14.100 Revision Method for some details.
Also, it's not uncommon to use numeric revs or similar for pre-production or similar 'revisions' with the initial production release being rev A (or '-' or ' '). In these situations there is arguably a case for 'rev A' change indicator, though it wouldn't' be my choice.
However, getting back to the OP which is about initial release...
I've never seen symbols for true initial release. However, I have seen comments either in the ECO or the rev block explaining that the drawing was based on drawing xxx etc., or that it was previously proto rev 1 with no change, or similar.
In your case, I'd say it's probably best not to have it on the drawing and worry about indicating to manufacturing what changed from the old drawing on the ECO or similar.
What is Engineering anyway: FAQ1088-1484: In layman terms, what is "engineering"?
RE: Rev A symbol on a Rev A print ??
If a revision is made, then the title block shows "Rev. 2." Strange...
John-Paul Belanger
Certified Sr. GD&T Professional
Geometric Learning Systems
RE: Rev A symbol on a Rev A print ??
In a way this is unfortunate, because I've been involved with prints in similar situations where it would have been handy to have an easy way of saying 'like print XXXX, except with changes A, B, C...'. Indicating in supporting documentation is all well and good, but often that documentation gets stripped away from the drawing eventually. Mostly I'm thinking of time wasted reprogramming similar parts because the programmer never got the memo/documenation of 'similar to part 123 except...'.
RE: Rev A symbol on a Rev A print ??
I think I understand what you co-workers are trying to do. I think the revision triangle is too weird to work.
They could always put a note on the drawing describing the differences between the old and the new drawings. This all is meaningless if you do not tell the user the number of the old drawing.
RE: Rev A symbol on a Rev A print ??
"Good to know you got shoes to wear when you find the floor." - Robert Hunter
RE: Rev A symbol on a Rev A print ??
RE: Rev A symbol on a Rev A print ??
Thanks guys,
Jack
Jack Lapham
Engineering Systems Administrator (E20)
Leupold & Stevens, Inc.
www.leupold.com
Dell M6400 Covet
Intel Core 2 Duo T9800, 2.93GHz, 1066MHZ 6M L2 Cache
8.0GB, DDR3-1066 SDRAM, 2 DIMM
1GB nVIDIA Quadro FX 3700M (7.15.11.7950)
160GB Hard Drive 9.5MM 7200RPM FFS
W7x64 | sw-01: 55.92
SolidWorks 2010 x64 sp4.0
Enterprise PDM 2010 sp
RE: Rev A symbol on a Rev A print ??
I'm torn on revision indicators on drawings because on the one hand it quickly indicates to an outside manufacturer what dimension may have changed from the previous revision they have made before; on the other hand if you an indicator was accidentally omitted and your manufacturer doesn't notice you might get an out of spec part anyway.
Sure it's the job of the manufacturer to make it to print but that's not much solace when you have to send your whole lot back because of a stupid mistake and wait to get inventory that is needed for a product launch.
RE: Rev A symbol on a Rev A print ??
Jack Lapham
Engineering Systems Administrator (E20)
Leupold & Stevens, Inc.
www.leupold.com
Dell M6400 Covet
Intel Core 2 Duo T9800, 2.93GHz, 1066MHZ 6M L2 Cache
8.0GB, DDR3-1066 SDRAM, 2 DIMM
1GB nVIDIA Quadro FX 3700M (8.17.12.5896)
160GB Hard Drive 9.5MM 7200RPM FFS
W7x64 | sw-01: 55.92
SolidWorks 2010 x64 sp4.0
Enterprise PDM 2010 sp
RE: Rev A symbol on a Rev A print ??
What is Engineering anyway: FAQ1088-1484: In layman terms, what is "engineering"?
RE: Rev A symbol on a Rev A print ??
ASME standards need to be followed and in house standards to be written then followed. Whatever revision scheme is selected, the company needs to be educated in it.
Vendors need to be aware of them.
It's when everyone in the company 'thinks' what he/she is doing in the correct way is when others get confused.
And parts are made wrong my the machine shop or vendor because of inconsistencies.
Setup standards and a plan, stick to it. Every once in a while you will come across someone that's capable of being educated.
Chris
SolidWorks 10 SP4.0
ctopher's home
SolidWorks Legion
RE: Rev A symbol on a Rev A print ??
If we put the level 1 change symbols on the drawing we would also have to create an alteration record which would have to refer to the other drawing. More trouble than it's worth in MHO.
RE: Rev A symbol on a Rev A print ??
-TJ Orlowski
RE: Rev A symbol on a Rev A print ??
Here's the possible argument:
"The revision symbol may be used to identify an item or area of change on the drawing." ASME Y14.35 paragraph 5.4. How can their be a change on the drawing if the drawing is new? Rhetorical question. That should end the conversation. ;)
However, if it doesn't, ask for justification of why there should be an exception to the standard. To this, the antagonist may say, "Where does the standard say we cannot use revision symbols on new drawings." To this you can say, "the ASME gives us rules and processes to follow; not to not follow." The antagonist will then look up the word "not" in the standards and find that it is indeed used at some point.
As this point, the argument gets estoteric and has nothing to do with the topic at hand. With no resolution, the whole thing is just silly. Compromise is necessary.
The symbols can be used in a way not specified by the standard if their non-standard use is defined on the drawing. Add a note to the drawing that says why they are there and what they are showing in relation to the old drawing (which should be mentioned by "name").
Matt Lorono
Lorono's SolidWorks Resources & SolidWorks Legion
&
RE: Rev A symbol on a Rev A print ??
The fabricator is required to produce the part on the print. It shouldn't matter to them what revision it is. Perhaps I am designing a custom stool, and the customer has changed their mind 8 times about how tall it should be. So I keep changing the length of the legs and sending it back for their approval before I start fabrication. I don't see a problem with using revisions to keep note of these changes. When I finally get the customers approval and release the drawing for fabrication, why should I need to "reset" the revision level?
-- MechEng2005
RE: Rev A symbol on a Rev A print ??
What is Engineering anyway: FAQ1088-1484: In layman terms, what is "engineering"?