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MBD Implementation

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I didn't want to hijack another thread for this, an interesting article on the status of MBD implementation. It is possible, but some convincing still needs to be done.
[snail]

"Good to know you got shoes to wear when you find the floor." - [small]Robert Hunter[/small]
 
Click to expand...
Trust is the key missing component, as indicate in the article. A second critical component is reality; just because it's a solid model doesn't mean all of the information is automatically there. Too many companies think they are doing MBD by passing an unannotated or inadequately-annotated CAD model over the wall; they believe they are saving themselves money while they are really abdicating responsibility for the detailing to someone downstream who doesn't know the functionality of the part.
Personally, I support the migration, but it has to be well thought out, fully implemented and supported.

Jim Sykes, P.Eng, GDTP-S
Profile Services TecEase, Inc.
 
I agree... trust is the issue. "Reality" is only an issue of trust. An approved engineering drawing can just as easily be missing critical information as a MBD part. Of course, we still don't need dedicated checkers, do we.[deadhorse]

"Good to know you got shoes to wear when you find the floor." - [small]Robert Hunter[/small]
 
The solid model still must contain all the information that would've been put into a drawing. Many people seem to forget that the purpose of the drawing is to be a contract. Without that same information in the model there is no meeting of the minds, an essential component of contracts.

Matt Lorono
Lorono's SolidWorks Resources & SolidWorks Legion

http://groups.yahoo.com/group/solidworks & http://twitter.com/fcsuper
 
Before I was laid off from Boeing a year ago, I took a 40 hour class to learn CATIA.
I think MBD is a good process, but too time consuming IMO.
It seemed to me at the time that there must be a more efficient way to do this.
I had one chance to see it actually in work, still looks to me to be not very efficient.

Chris
SolidWorks 10 SP4.0
ctopher's home
SolidWorks Legion
 
Yeah, Jim, it is...
The checkers I have had to work with taught me a heck of a lot. Haven't worked with any real checkers myself in many years, having to rely on self-check or peer-check instead. It's just not the same.

"Good to know you got shoes to wear when you find the floor." - [small]Robert Hunter[/small]
 
I think checkers are out of vogue right now because many are under the impression that drawings well enough understood. Once cause may be that ASME and ISO are partly to blame because they give a false sense of security to management and others. Contrastly, another cause is that many engineers and managers simple do not understand that drawing is a contract that has a particular language and needs to be fully defined and unambiguous. I've seen some engineers uncomfortable with using ASME standards because it doesn't match what they've self-taught themselves (and are therefore they are under the impression others think the same way enough though no documentation supports their opinions).

Matt Lorono
Lorono's SolidWorks Resources & SolidWorks Legion

http://groups.yahoo.com/group/solidworks & http://twitter.com/fcsuper
 
Checkers, pah, what nonsense.

We can rely on the professionalism of the engineers that do the drawings/MBD (because in the days of CAD drafters/designers are clearly obsolete too) to ensure drawings that fully conform with relevant standards and don't have any errors - combined with the fact the CAD tools auto dimension etc. for you. Being professionals the Engineers will ensure they know and understand relevant drawing standards without any need for formal training or certification.

The thing I didn't see mentioned was the interface between the user and the model. In a good drawing it's all laid out there for you. In MBD it can be buried in one of the 'set views' - or be something you have to 'interrogate' the model to find.

Given you still have to put all the info in the MBD that would have been in the drawing, I still struggle to see where the massive time savings everyone claims are.

If CMM can reliably read in the tolerance info to 'automatically' inspect parts then I suppose that saving may be significant. However, where else does it save over separate 'minimal dimension' drawing & dumb model?

Doesn't help when some of the managers etc. pushing/proposing this haven't really got a clue as it wasn't part of their MBA studies.

It's prone to the same sort of abuse as default block tolerances too.

Posting guidelines faq731-376 (probably not aimed specifically at you)
What is Engineering anyway: faq1088-1484​
 
Kenat ... you're funny! As if Engineers have time to do any of that! The unfortunate reality is that "management" has downgraded the skillsets of those involved at all levels and place an increasing burden on all-too-fallible technology. I like technology, but I prefer craftsmanship, whether it's on the engineering end, shop side, or metrology.

Jim Sykes, P.Eng, GDTP-S
Profile Services TecEase, Inc.
 
Time savings only come from the fact that the model is used directly (or nearly directly) in the manufacturing process. Fully detailing a model is actually harder and takes more time than a drawing would in most cases, from what I've seen. Hence, we use the shortcut of applying a common tolerance to everything. :)

Matt Lorono
Lorono's SolidWorks Resources & SolidWorks Legion

http://groups.yahoo.com/group/solidworks & http://twitter.com/fcsuper
 
...which makes sense, because dimensioning the model is redundant. The only added requirement is the tolerancing.

"Good to know you got shoes to wear when you find the floor." - [small]Robert Hunter[/small]
 
However, for some tolerances you have to have a dimension to apply them to...

(unless 2009 version has made some changes)

Posting guidelines faq731-376 (probably not aimed specifically at you)
What is Engineering anyway: faq1088-1484​
 
still true, Kenat. As Matt said, it actually takes more time to annotate a model than doing the traditional 2-D drawing. I don't see any time savings in reality, except for the simplest of geometries perhaps, and even that's questionable. Where I really see the benefit is in reduction of deforestation and in ensuring the latest release is the only one in use as the user pulls up the latest released model at all times. Even just going to the step of releasing electronic drawings (2-D) improved that particular situation effectively. There are a lot of issues that pop up too; does the downstream user know how to properly and effectively interrogate the model? I've seen eng support guys not do it properly, so what chance does an undertrained (on CAD) shop guy have?

Jim Sykes, P.Eng, GDTP-S
Profile Services TecEase, Inc.
 
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