Drawing Number System - Do you still indicate dwg sie in the code?
Drawing Number System - Do you still indicate dwg sie in the code?
(OP)
I'm working on developing a new (and significantly improved, hopefully) drawing number system. Many of the systems I've seen in the past included a character within the drawing number that indicated the drawing size (either small, medium or large or A, B, E, etc). Is there any reason to do this anymore? I can't see the reason for it now or even before CAD, except if drawings were stored by size. This is a moot point for CAd systems, I would think.





RE: Drawing Number System - Do you still indicate dwg sie in the code?
Chris
Sr. Mechanical Designer, CAD
SolidWorks 05 SP0.1 / PDMWorks 05
ctopher's home site
RE: Drawing Number System - Do you still indicate dwg sie in the code?
Having said that, I've never seen the drawing size indicated in the PART number either, but have seen it in the DRAWING number. I think you agree that the drawing size needs to be in the TITLE BLOCK, but what abuot the drawing number?
RE: Drawing Number System - Do you still indicate dwg sie in the code?
Sorry if I'm not much help.
Chris
Sr. Mechanical Designer, CAD
SolidWorks 05 SP0.1 / PDMWorks 05
ctopher's home site
RE: Drawing Number System - Do you still indicate dwg sie in the code?
As a side note, are the part numbers you are used to significant (i.e. they tell you something about the part)?
Thanks for the input.
Troy
RE: Drawing Number System - Do you still indicate dwg sie in the code?
With your system, how do you link a part to a drawing?
If the part number is not the drawing number then it seems a cross reference of some sort is needed.
Back to your actual question. Other than cases where paper drawings are filed by size, I don't see any reason to include the drawing size in the drawing number. One reason not to. What if you originally check out a "C" number, but your part gets complicated and you need more sections and details then you originally thought. If the sheet size is not part of the drawing number you are free to simply blow away your C size border and put in a D or E size border. If "C" is part of the number you have no choice but to go to multiple sheets.
Very few companies use significant part or drawing numbers. There are always exceptions to the rules used to assign significance.
RE: Drawing Number System - Do you still indicate dwg sie in the code?
While I have seen companies attempt to use significant part numbers, this almost always leads to problems later (when the product line expands, for example).
As for signifying the format size in the number, I have never seen this done, and don't see any advantage of doing it with CAD drawings.
RE: Drawing Number System - Do you still indicate dwg sie in the code?
Chris
Sr. Mechanical Designer, CAD
SolidWorks 05 SP0.1 / PDMWorks 05
ctopher's home site
RE: Drawing Number System - Do you still indicate dwg sie in the code?
MintJulep: I have been thru the analysis of significant PART numbers and agree that insignificant PART numbers are the way to go for many reasons. In my opinion, there needs to be a cross reference for drawings somewhere anyhow. For example, the system I saw with Worthington had a letter signifying the paper size followed by a sequential number (5 digits I think). There was no way to determine if a pump casing drawing had been made without drain taps, for example, as no cross reference existed. Most manufacturing companies utilize some MRP or similar computer system, which becomes the backbone of information for the company. Each separate list or cross reference creates problems in maintaining and/or linkning the databases. The natural draw towards significance (part or drawing number) is for indexing w/o having to always go to a x-ref.
Again, perhaps my fears are pre-CAD based, but I shudder to think of maintaining 5 separate drawings of the same mold/pattern/part made from 5 different materials. Sounds like a sure way to create a descrepancy at some point.
Help me get over this hang-up: the 1:1 system doesn't seem any better than the one I've seen, which btw the way works like this: a drawing number coupled with a material code must equal one unique part number. (Ingersoll-Rand).
RE: Drawing Number System - Do you still indicate dwg sie in the code?
I would be worried about the drawing + material code = part concept. Consider:
Pump casing originally designed to be cast from ductile iron. The designer looks at the pressures involved, forces on the input and output flanges, temperatures, etc, and designs a casing giving consideration to the material properties ductile iron. The foundary looks at that drawing and detrimines the actual shape that the mold (or plug) needs to be to account for shrinkage as the thing cools, where there are gates needed, and other foundary stuff. The foundary creates a pattern drawing for this.
Now a new customer comes along and says "I saw that pump you made for this other guy, I really like it, but I want it in aluminum." The same casing in aluminum will not behave identically as the ductile iron that the thing was designed for. It will be weaker. It may be more brittle. The thermal expansion will be different, which in turn will produce different stress patterns. The shrinkage in the mold will be differnt, so you can't use the same pattern to get the same part.
To me it seems like there are some serious potential problems here.
The design of a part MUST consider the material that it will be made of.
RE: Drawing Number System - Do you still indicate dwg sie in the code?
2469A010X15A001 which would be a pump casing (2469) in a 12x10x15 size (010x15) with 150 lb flanges (A) and drain tap only (001). The A is just a place holder. The same casing with 300lb flanges might be:
2469A010X15B001. or with vent and flush taps and 300lb flanges:
2469A010X15B003. drop the last three digits for a casting drawing number.
This seemed to work better than M13325, which meant medium (B- size) drawing #13325. As I said before, alot of this headache has to do with legacy drawings, and I am starting anew (or trying to) with a MCAD system so the slate is clean.
It may seem trivial to those who only do what their company has implemented (the way we've always done it mentality), but we currently have significant part numbers, which IMHO, is a joke and drawings that use the significant part numbers as the drawing number. We also have multiple materials that are similar in shrink rate, strength, etc that don't require mods or different drawings and I fail to see the attraction of maintaining two seperate but identical drawings.
Many thanks for the discussion.
RE: Drawing Number System - Do you still indicate dwg sie in the code?
Chris
Sr. Mechanical Designer, CAD
SolidWorks 05 SP0.1 / PDMWorks 05
ctopher's home site
RE: Drawing Number System - Do you still indicate dwg sie in the code?
RE: Drawing Number System - Do you still indicate dwg sie in the code?
RE: Drawing Number System - Do you still indicate dwg sie in the code?
TZellers, I'd be interested in hearing how your project turned out.
RE: Drawing Number System - Do you still indicate dwg sie in the code?
Chris
Sr. Mechanical Designer, CAD
SolidWorks 05 SP1.1 / PDMWorks 05
ctopher's home site
RE: Drawing Number System - Do you still indicate dwg sie in the code?
Institute for Systems Research
It's a pdf file so you need adobe or a equal viewer.
RE: Drawing Number System - Do you still indicate dwg sie in the code?
RE: Drawing Number System - Do you still indicate dwg sie in the code?
ctopher,
Our drawing numbers look like:
B-5701, B-5702, B-5703 (B size)
D-7589, D-7590, D-7591 (D size)
Our part numbers look like:
19578, 19579, 19580, 19581
For assemblies we do:
A-19582, A-19583
we also do groups and material options:
19563A, 19563B (different materials, same shape)
19563-1, 19563-2, 19563-3 (same family, some dimensional differences)
A-19563-1, A-19563-2 (different assembly options)
RE: Drawing Number System - Do you still indicate dwg sie in the code?
No problem with that dwg system. Having the size with assemblies is not consistant with parts, and is not needed because the size is indicated with the dwgs.
Also, I would not use the dwg size with any of the files names in CAD files. It would be easier in the future to keep track if the dwgs were to change size.
Sorry, but at the beginning of this thread, I thought you were using the dwg size within the file name, i.e. 12345D.
Chris
Sr. Mechanical Designer, CAD
SolidWorks 05 SP2.0 / PDMWorks 05
ctopher's home site
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