We have better tools, but? 11

[BillBirch]

Recent postings give me a great cause for concern about the lack of knowledge of fundamental principals.

One guy writes that he is designing an ROV and wants buoyancy explained.

Another is designing a pump and wants to know how to calculate the moment of inertia and then discloses that he plans to use three bearings - (indeterminat loading and difficult to align).

Yet another was designing a rotating welding manipulator handling loads weighing tens of tonnes, which was eventually red flagged due to the heat that the thread was generating.

In all cases the posters referred to their solidworks designs. Are we getting blinded by the sophistication of the software and forgetting that garbage in = garbage out applies with software, or indeed any system.

I only know for certain that the last example was from an unqualified, but perhaps over-enthusiastic kid, but I hope that the other two are drafters with a healthy curiosity. If so, I hope that they are given sufficient experienced engineering supervision so that they do not waste too much time, design something impractical, dangerous or all of the above.

On the other hand, if the other posters are qualified, it suggests the following.

- Quality of education. In the examples given, buoyancy is a fundamental of physics that should have been understood in high school. Machine element design has fundamentals regarding constructability that should have been learnt in college.

- Insufficient supervision or inappropriate tasking. Are senior engineers too occupied with management to give the younger guys the necessary mentoring, and related to this, are the young guys being asked to undertake roles above their experience. Similarly, are companies cutting costs by employing graduates only, thus avoiding higher pay rates. This is a common complaint on this website, and although it is heartening to see the younger guys shouldering the challenge, it is also a concern that they may not realise the exposure of their situation and could easily be thrown to the wolves.

- Inadequate recruiting practices. Not everybody was good in all subjects in college and you would expect that career paths would reflect particular strengths. I may be wrong, but I suspect that ptoficiency in CAD seems to be driving a lot of selections. Are the correct skills being overlooked by recruiters who simply see a candidate as a two-for-the-price-of-one find, someone who can draft and do a bit of engineering?
Regards,
Bill

P.S If anybody recognises themselves in the examples, no offence was intended. The purpose of this post was not to ridicule, but to highlight what appears to be unreasonable expectactions on our junior colleagues or associates.

 

[SomptingGuy]

GonzaloEE, I am often guilty of giving terse replies that can be misunderstood (and posting jokes that others then feel the need to explain).

What I meant to say is that there is generally no need to memorize formulae or equations if you actually understand the physics behind them. Indeed, memorizing formulae is generally a bad thing. By extension, memorizing them by way of spreadsheets is worse still.

If you already haven't, read Feynman's "Surely you're joking..." book. There is an excellent description in it of (I think Brazillian) engineering education where the students were memorizing everything and understand nothing. It also encapsulates another theme on this thread, teaching and why professors teach.


- Steve

 

[GonzaloEE]

No problem, thanks for explaining it to some of us not checking the site too often.
I agree 100% on that of memorizing. Though I don't know of Brazilian engineering, 'passive' education is a common issue in that region, along with language barriers and low education budgets. Maybe European educational style -more theoretical, has something to do with that too.
No surprise engineers with a global-industry-level education end up hired by US companies for R&D and 'real' engineering projects, while most locals work on sales/management.
Well, education across continents is a interesting subject I'll leave for another thread.

I remember a college teacher joking about french theory-friendly engineering, saying 'they manage to build cars by working out formulae for n-wheels vehicles, then making n=4'

 

[TheTick]

(especially managers...) repeat after me...
"CAD is not engineering"
"CAD is not engineering"
[!]"CAD is not engineering!!!!!!!!!!!!"[/!]

 

[zdas04]

Tick,
I think you have issues.

David

 

[spongebob007]

Analysis software should NEVER be looked at as a substitute for product testing. Analysis is meant to flush out design flaws early, eliminating the costly and time consuming trial and error of prototyping cycles.

Good FEA results should give the engineer/designer the confidence that his design will pass reliability testing the first time around.

 

[ivymike]

don't say never... I doubt many people test flywheels these days.

 

[GregLocock]

Yup, I do a whole bunch of safety related tests on the computer that are too dangerous to perform in real life.



Cheers

Greg Locock

SIGlease see FAQ731-376 for tips on how to make the best use of Eng-Tips.

 

[Twoballcane]

I do agree with spongebob. Analysis is really the crystal ball of engineering. It is a great way to see in the future, but your destiny is still uncertain till it happens. FEA is all math that will predict what will happen. There are to may other dynamics that that the software does not take into consideration, also, the model is only good as its creator’s assumptions. The proof in the pudding is in the test both thermally and dynamically. I will always do a prequalification test to chase the bugs out and then send it off for the real qualification test. You’ll get more sleep this way.

Tobalcane
"If you avoid failure, you also avoid success."

 

[SomptingGuy]

There is more to CAE than FEA.

A simulation that gives you insight into why something behaves the way it does is a valuable thing in its own right. As well as "flushing out design flaws", a good simulation tool will allow you to experiment with no end of alternative solutions to a problem.


- Steve

 

[DHambley]

Ah, you brought up one of my most annoying issues.

Your question, "..are we getting blinded by the sophistication of software...?"

Yes. The answer is Yes. It has nothing to do with old engineers or young engineers. It's the blind respect for software.

I have a present example right now. I'm working on an electronic product for a military application. One engineer took a circuit from a published paper (which was intended for a different application). He has spent the last 2 months performing PSpice analysis and other simulations. Neither his actual hardware nor the Pspice output meet the customers specifications. No inventive new design has been performed to make the product work, just analyzing-to-death a circuit which does not work.

What's our firm going to do when the customer asks, "Where is our box?" Are we going to say, "Uh, it doesn't work, but look at the 25lb stack of paperwork and analysis!!"

 

[ivymike]

how does that reflect blind respect for the software?

 

[DHambley]

Ivy, I'm using the term a little differently than the other posters. The "respect for software" I'm refering to is that somehow these guys think that they're supposed to keep operating a software program nonstop instead of analyzing and solving an engineering problem. I also see similar respect for software in the FEA guys here (one of which is not degreed). Just the fact that a bunch of time was spent producing a huge report with the word "FEA" written on the coverpage does not mean that a proper failure modes and effects analysis was performed.

 

[ivymike]

Well, you certainly can do an FEA without doing an FMEA.

Sounds like a strange place to work.

I've run across a few CFD analysts who were little better than a "wet interface" for the software - without an engineer to guide them, they'd just make multi-colored pictures all day.

 

[SomptingGuy]

When you have to field support questions for a simulation tool you develop, it is stunning and scary just how little some of the users/questioners actually know and understand. Often a question will come in that makes my heart sink. For example, a CFD researcher (his choice of title) asked us last week what we meant by "total temperature".




- Steve

 

[drebelx]

Many blame education which has been producing knowledgeable engineers inconsistently for over a century.

Many blame the lack of mentoring which has also happens to be an inconsistent source of quality knowledge.

Many blame new fangled computer programs that are being used by inconsistent knowledgeable engineers.

Few engineers talk about hands on field experience.

Few engineers actually have hands on field experience.

Few engineers actually talk about the lack of hands on field experience engineers have today.

How can anyone be a true engineering expert in something they have never empirically experienced?

 

[KENAT]

drebelx, what do you mean by hands on experience.

Do you mean something like a structured apprenticeship or just having worked on the shop floor/site whatever as a labourer?

I've seen people of varying quality come from both, the apprenticeships, especially those who'd done the apprenticeship a few decades back, were the better of the two though.

KENAT, probably the least qualified checker you'll ever meet...

 

[DesignerGuy16]

"90% of what makes me a CAD wiz is what I learned in high school geometry."

Now that's truth right there. Except kids don't even get that today, they get thrown right into 3D modeling with no real appreciation for reading/creating blueprints.

CAD's a great "tool" to graphically express how something should be manufactured and assembled. No it doesn't replace engineering, but the two in tandem, and in the right hands, can create some pretty amazing things in a short period of time.

You still need calculations for sizing items for the application, and tools like FEA to prove and improve the base design.

I really think that colleges are a prep for the field, and if anything prepare enough to know where to look and how to solve problems. My opinion is that job specific traits and areas of expertise be learned in the field under guidance of more experienced engineers. Otherwise you have theory with no application and you'll never truly remember or grasp fully what you're learning.

I like to tell anyone I'm interviewing for that I may not know everything, but I'm a fast learner, adaptable and most importantly know how to use my tools effectively. Otherwise I'm selling myself as something I'm not, and at the same time it opens the door to a broader future experience.

Just my $.02

James Spisich
Design Engineer, CSWP

 

[drebelx]

@KENAT

Exactly. Apprenticeship is part of what I'm talking about.

There is also a problem at the family level where children are expected to learn everything they need to know from mandatory schools and other structured programs. There is very little room for children to explore on their own the physical realities that make up our world.

Childhood curiosity and the excitement from it is suppressed. Large numbers of children are designed to be given tasks, apply a solution based on concepts generated in the past and repeat.

 

[ctopher]

The first IT person (help desk).

attached...

Chris
SolidWorks/PDMWorks 08 3.1
AutoCAD 08
ctopher's home (updated Aug 5, 2008)
ctopher's blog
SolidWorks Legion

 

[FC2008]

I'm a new guy as well. Started working three months ago (Mechanical). My school sucked, the teachers were useless and everything I know I learned my self.

I didn't do any FEA in school and one of my first assignments at work was do do a FEA. Instead of doing that, I just did what I knew..Made assumptions, drew a free body diagram, added forces and did simple calculations. Luckily, it turned out to be more than good enough.

This just goes to show how much everyone these days relies on computers. I only have a Bachelors degree in mechanical engineering, and I'm a firm believer that without good knowledge of solid mechanics, one should not do computer simulations on solid mechanics... I do not have this knowledge, and until I do, I refuse to do any such analysis.