dimension ID's on drawing 1

[loughnane]

I'm setting up drawing standards and think I will have utility for attaching a dimension ID to each drawing on a print. By this I mean literally every dimension on the drawing will have an ID number. I have several downstream reasons for this, but the underlying principle is that if it is worth putting on a drawing, it is worth giving it an ID other than "that dimension in Zone B6 that is 1.4... I mean 1.41".

Has anyone had experience with such a system? Thoughts in general?

Chris Loughnane - Product Design

http://www.pdnotebook.com

http://www.twitter.com/_chrisloughnane

 

[drawoh]

loughnane,

SolidWorks does this automatically. Your CAD probably does too. If you need an ID, is there any reason you would not use your CAD's?

--
JHG

 

[loughnane]

@drawoh

My understanding is that if I delete dimension "X" and add dimenson "Y" that the SolidWorks-assigned dimension ID for dimension "Y" will be the same as the one for dimension "X". This would have negative implications for traceability.

Perhaps I am missing some functionality?

Chris Loughnane - Product Design

http://www.pdnotebook.com

http://www.twitter.com/_chrisloughnane

 

[KENAT]

Sounds like a way to get a horribly messy and confusing drawing, as far as I know it's not covered by ASME Y14 series drawing standards - for what that's worth.

I get doing it on an inspection print, maybe even have it as a layer/setting (or whatever term your CAD uses) that QA can turn on when they generate their copy but is by default off.

However, having it on the body of the Engineering drawing rubs me the wrong way - but like I say I don't think I can quote chapter and verse to say why I think it's wrong.

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[dgallup]

I've seen addon packages that will put inspection bubbles on drawings, either integrated into the CAD package or working from PDF or JIFF files. I've not seen a CAD package that had it build in. Pro/ENGINEER has internal ID's for each dimension and GTOL, you can toggle the display between the dimension and the ID but there is no way to show both. It still won't have ID's for things like notes and surface roughness symbols.

I personally hate it, makes a huge mess of the drawing.

----------------------------------------

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[ewh]

Wouldn't you still have to locate the ID the same as the dimension?

“Know the rules well, so you can break them effectively.”
-Dalai Lama XIV

 

[MintJulep]

Conceptually: Good idea.
In practice: Almost certain to be a disaster.

 

[CheckerHater]

Sounds terrible.
Haven't seen anything like this in 30 years.

loughnane, how unique is your situation, to justify approach completely foreign for most of the world?

And about Solidworks:
If you "delete dimension "X" and add dimension "Y" ", it actually calls for drawing revision. So, in rev.B Dim37 equals 1.41, in rev.C Dim21 equals 1.41. Isn't it still traceable?

 

[loughnane]

@CheckerHater the product itself isn't mechanically unique, but I think there is enough value in the process to warrant the PITA identifying the dimensions is sure to be.

Pardon me while I stand up on my soap box...

Dimensions are about as fundamental a building block as you can get in mechanical engineering, and yet our default way of doing things is to reference "that 1.45 dimension in zone B2" which may change (both value and zone) in subsequent revisions, meaning that there is no persistent identifier throughout the life of the part. This ambiguity makes inspection, analysis, and traceability a very manual process.

Imagine the value of having an ID for every dimension on a drawing. Now also imagine that you build an exhaustive mathematical model (tolerance analysis) of your assembly. While you are in production you will inspect the few critical dimensions every so often, and on a less regular basis you will do occasional inspections of everything. Because each of the inspections is explicitly tied to an ID, you will be able to automatically pipe the inspection data into your mathematical model to see what dimensions are changing, what correlations between dimensions are changing, what tolerance stacks are shifting, etc.

So putting dims on every drawing is a pain, but it really could empower small hardware companies to do things much more efficiently.

Chris Loughnane - Product Design

http://www.pdnotebook.com

http://www.twitter.com/_chrisloughnane

 

[KENAT]

"it really could empower small hardware companies to do things much more efficiently"

I doubt it, because small hardware companies probably aren't going to have to resource to do all the other things involved in your ideal process.

Posting guidelines faq731-376

http://eng-tips.com/market.cfm?

(probably not aimed specifically at you)
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[3DDave]

To get whay you want, you need to uniquely identify the surfaces of the part, each of which will be controlled by dimensions and tolerances. Surfaces may share values for dimension and tolerance, but the dim's & tol's will be unique to each surface.

The good news is, surfaces are uniquely identified in CAD models. The bad news is, relating them to the dimensions and tolerances that govern them is not readily available.

 

[CheckerHater]

Looks like seeking solution to non-existing problem. Especially for "small companies"

 

[SDETERS]

We do this for inspection prints.
1. It is easier for us to put these inspection balloons on the print vs quality. Quality would have done this with a circle template and a pencil.
2. When we get a Quality report from the supplier the dimensions numbers from the supplier and our quality match up.

It works well for us. But I question what is a dimension. We only ID the feature of sizes and FCF frames. We do not ID the basic dimesnions. There are some other rules we use but every once in awhile we run into an issue with 2X or should this dimension get one or not.

 

[dgallup]

We always leave it up to QA. They take a rubber stamp with a hollow circle and arrow and stamp all over a paper copy of the drawing and hand write a number inside each circle. I agree it is a nightmare if we get 2 reports with different numbering schemes. But there is no way I will clutter up my drawings with those symbols. I've seen places that do it, the drawings are hideous and the suppliers ignore them.

I don't actually see any value beyond the inspection process. Pumping QC data back into your stackup does not actually change your tolerance analysis.

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The Help for this program was created in Windows Help format, which depends on a feature that isn't included in this version of Windows.

 

[ctopher]

My 2 cents.
Use SW how it's designed to be used, and dim drawings so others can understand them.
Making them unique so YOU understand them, more room for errors and higher costs.

Chris, CSWA
SolidWorks 13
ctopher's home
SolidWorks Legion

 

[cbrf23]

I worked at a medical device job shop for a while, processing hundreds of parts monthly with constant rev changes from customers coming in last second.
After some research, we purchased a software product called Inspection Xpert.
We purchased their PDF compatible version, as the inspection department didnt have solidworks access and all of our customer prints were PDF format.
They do however have a version that supposedly integrates into SW, but I have no experience with it.

I thought overall it was a very nice program.
It made it simple to balloon and create inspection plans and it was easy to update or change when needed.
I liked the "grouping" so you could group a bunch of basic dims to their respective FCF.
I liked it because you can add custom fields, so we would have our programmers go in and for each dimension list what tool(s) was controlling the feature so that we could map our inspection plans to the process critical features.

It was a relatively affordable product IIRC.
We had one floating license, which is fine if your workflow is sequential, but for parallel processing this can be a little tedious.

I didnt post a link to the software because I didnt want this post to come across "spammy" but you can google it.