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.

 

[jrhagen]

IMO I am OK with colleges not teaching CAD, GD&T or drafting anymore. All these concepts can be self taught quite easily after college. I do think that there should be some material in college that deals with manufacturing processes and industry standard practices. When I first started, I had a designer/drafter position. I read the pertinent standards and some material on mechanical drafting. I found the concepts very easy to grasp, what I had a problem with was determining what could actually be manufactured at a acceptable cost. I really didn't have any kind of grasp of what type of tolerances could be obtained using a given process. I found myself over tolerancing components for saftey when it wasnt really neccesary. As you all know, that can turn a $100 part to a $1000 part very quickly.

 

[KENAT]

graybeach, I'm not sure I'd necessarily propose sending them literally back to the drawing board, however I'd like the emphasis changed from learning a CAD system to learning how to draw/model to best practice/standards and tolerance etc. Especially given the range of CAD systems (I know AutoCAD is fairly standard in some industries but in others there's a range).

However, I'd still expect this to be a relatively small proportion of a typical Bachelors of Engineering.

Agreed Tick, I use little to nothing of my University Education directly when I'm doing CAD, it's mostly High School, and not necessarily the last 2 years!

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

 

[GonzaloEE]

Summary of an old lunchtime talk at my office:

Tools are just the thin thread we lay down to get through the labyrinth of project problems. Knowing the physics involved (or dusting off the books) gives us the whole map. Unfortunately for today's engineers (me included) deadlines often pushes us to rely on cookbooks, spreadsheets and software that thinks for us, then we are thinking 1% less every day, allowing 1% more of our day job to be done by machines and computers, making us 1% more replaceable every day.

Maybe those egyptians were more able to think on all layers of a problem, while making pyramids by just calculating square angles with threads and knots.

 

[SomptingGuy]

Cookbooks, spreadsheets, software? The ONLY things I've ever nneded to memorize are:

pV=mRT
(pV)^gamma = constant

Almost everything else of use to me can be derived from first principles.

- Steve

 

[HEC]

An interesting and facinating thread, I must agree with all said to date. As an experienced engineer (20yrs in the real world) I would make the following comments.

As a graduate, you are thrown into the deep end, get over it and remember your fundamentals... SomptinGuy, must use a lot of gas calcs, but there are other first principles to remember.
The education system I believe has moved from focusing on providing basic tools required, there is nothing wrong with rote learning, exams and failing those who don’t apply themselves.
When I entered industry, it was at the time industry was down sizing, it was hard to find good mentors. So I went and found them!
To the new graduates, always keep an open mind and be prepared to learn.

To the OP I have also notice the same disturbing trend on this site. Perhaps as a community we, should police these posts and red mark them for closer review by the moderators. Or alternately ignore the obvious bad questions.

Rant over.


Mark Hutton

 

[moltenmetal]

Yes, the forums here do bring out some true stinkers. But since nobody at Eng-Tips is asking for copies of peoples' university transcripts at the door, you've got to realize that some of the questions being asked are not being asked by engineers.

I agree with the previous posters who have said that the geniuses and dolts are still coming out of the schools in the same proportions.

There is definitely a tools believability bias. People give a digital display more credence than an analog one, whether it's on a watch, a caliper, a calculator, a pressure gauge or a thermometer. There's something psychological at work there. The same for a 3D CAD model vs a 2D etc: there's an inherent believability bias at work. As our tools get more complex and more powerful, we are left with an even more compelling impression that our models represent reality rather than just an abstraction based on assumptions and calculations.

A well-calibrated garbage detector is essential to being a good engineer- even more essential than in the past. The best calibrator is experience with the results of your own design. That's in a nutshell what the young'uns are missing, and what we (more) seasoned engineers must give them via mentoring. Too few of the young kids have been on the (real) tools, working with their hands, calibrating their commonsense. That problem HAS gotten worse, and it's parents who are to blame every bit as much as it is employers and schools.

A star to IvyMike for hitting the other nail soundly on the head: the trouble we old b@stards can tend to have is that we can easily begin to believe our own bullsh*t after a time. Even the best calibrated bullsh*t detector reads wrong if the person using it is the source!

 

[Helicopterjunky]

Engineers.....Spend some time and some of that great experience you claim to have helping young engineers when they need it. New tools that perform accurately are great.
I haven't forget the eighties when you couldn't buy an enginering job and the old timers kept everything close to the vest as their security blanket from layoffs.
Also, I remember all the meetings when engineers argued in public (look at me, look at me, I am right!) as management and business folks just shook their heads in amazement.

 

[btrueblood]

"it was hard to find good mentors. So I went and found them!"

Star for that, HEC. It is difficult sometimes to suffer the crotchety old ba$%@rds, but if you can get past the bluster, they have wisdom to teach. For those of us approaching COB age, we have to be ready to suffer the young twits coming up behind, and coach them (and remember the old mule skinner's advice: step 1, whack it in the head with a 2x4, then you've got its attention).

 

[drawoh]

HEC,

Rather than red flagging, I would prefer to see people answer bad questions as diplomatically as possible. You may just succeed in keeping a grossly underqualifed designer from attempting difficult, safety related design. It may be something that can be printed off and presented to the boss. A red flagged message just disappears into the ether.

I did not see the bouyancy, or the welding manipulator threads, but I did respond to the one on centrifugal pump mass moment of intertia. As best as I can recall, I was taught MMoI in the second semester of a Mechanical Engineering Technology course. A lot of stuff is built upon this base, so my assumption was that the OP has had no engineering training.

I have encounted people who appear to have little expertise beyond operating CAD software. I assume most of them took CAD courses. I suspect that some of them acquired pirate copies of SolidWorks or whatever, and installed them on home computers. Right now, some of these people are learning to operate FEA. Watch out!

JHG

 

[KENAT]

Agree that pointing out that they may be in over their heads might be better for the public safety than just immediately red flaggin the thread. No guarantees it'll stop them but one can hope it might sow the seeds of doubt at least sometimes.

Moments of inertia, I was I think 17 & in high school, then again I was masochistic enough to take double Math, Pure & Applied A level.

Drawoh, you're last paragraph is scary accurate from what I've seen. The worst thing is when these are the people teaching the CAD class.

An important skill that could perhaps be added to engineering programs is 'how to work with crotchety old farts that have forgotten more than you'll probably ever know' or something like this. Part of this course would be pointing out that they grew up & were educated in a different time & culture, they may not meet all the current standards of PC behavior etc but this doesn't automatically make them A holes.

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

 

[SomptingGuy]

"crotchety old farts"!!

These are the people who jumped at the chance of early retirement at the last lay-off period. They now come back on contract because of their love for the technical aspects of the work. For us non-farts they are a brilliant resource. One day I'll be one.

- Steve

 

[Helicopterjunky]

Crotchety old fart engineers network:

Crotchety old fart machinists
Crotchety old fart welders
Crotchety old fart scientists
Crotchety old fart salesmen
Crotchety old fart draftsmen and checkers

Last but not least..........

Other crotchety old fart engineers

 

[drawoh]

KENAT,

I do not think I have been taught CAD by grossly untrained people. My CosmosM training has been from engineers with graduate degrees. They know their stuff!

I am curious about how comforable they are with us non-engineers running FEA? Are they confident that we are professional enough to refuse work that is beyond our ability? We are being told such great things about the FEA. Can they be held responsible if we decide we are qualified to analyze pressure vessels or high, elevated platforms?

JHG

 

[HEC]

drawoh,

The problem with software salesmen is generally they believe that their software is infallable. It is not. It is based on engineering theory that makes simplifications (Assumptions) based on observation. The key is knowing the assumptions and when the design or model is getting "close to the edge". FEA is, dare I open the TLA, Finite Element Analysis vis all the basic theory of strength, fluid or other physical phenomenom over small parts of the model. It is very dependant upon how the model is assembled and its boundary conditions. The normal caveat of GIGO. The key then is knowing when it is wrong. This is generally based on experience and if the big numbers add up.

1. If it doesn't look right it probably is not right.
2. The difference between theory and practice is generally greater in practice that in theory!

Cheers

Mark Hutton

 

[btrueblood]

"An important skill that could perhaps be added to engineering programs is 'how to work with crotchety old farts that have forgotten more than you'll probably ever know' or something like this."

Dunno about the rest of you, but that was part of both BS and MS level junior & senior design courses. Junior project required us to interface with our shop supervisor, a crusty old German guy (we suspected he was ex-Nazi, but no proof). Senior design course I've already commented on.

At my first job, several designers of the original F-1 rocket engine (you know, the one that put men on the moon?) were due to be laid off, and were typically patently ignored (as whining naysayers) in most meetings by the middle management layer between me and them. Some of these guys had stacks of blueprints, binders full of test data, floppies full of codes... A few of us young punks snuck over to their offices when time allowed, and absorbed, alternatingly, good-natured abuse, long soliloquies about how we had it easy (they used to walk uphill to the test lab, both ways, in blinding snowstorms), and where the good stuff was in those binders, floppies, and blueprints. We did some neat stuff, combining some of the old codes with some of the new ones, figuring out how to anchor some of the new codes with the old data... And, on at least one occasion, one certain young punk asked a COF to a meeting where he'd felt out of his depth...and the COF helped that particular design team to save the day by suggesting a test method that allowed them to successfully demonstrate a particular engine for a congresscritter without it blowing up like in all prior tests.

 

[drawoh]

HEC,

As I noted, we are dealing with graduate engineers, one of whom teaches mechanics of materials at a nearby university. They know the limitations of FEA.

Perhaps what they do not know are the limitations of some FEA operators. A lot of idiots probably shut up when they realize they are talking to an engineer with a masters or doctorate degree, whereas, they don't when they are talking to me.

I have been told "We need FEA so that we can do structural analysis." I have also been told that all mechanical parts are 30% overweight, presumably due to people not having FEA. Structural or fluid or thermal analysis is a process of operating the right software. Do they understand the answers? I do not know.

JHG

 

[KENAT]

drawoh, speaking as someone with my bachelors, just having a bachelors doesn't necessarily mean you know it all. I've had people teaching stuff that upon closer examination they didn't really know/understand/have real life experience of. I've also had people with advanced degrees asking for FEA and not mentioning hand calcs when they probably would have been faster & easier to do. Although if your guy teaches at a uni then there's presumably some hope.

One point on FEA, it's usually a good idea to validate your FEA with at least a rough 'order of magnitude', I know some 'designers' who could probably do this, at least for simple cases (perhaps better than I), but I know plenty that couldn't so I have concerns in that area as you originally flagged.

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

 

[GonzaloEE]

SomptingGuy, congratulations if you are able to survive with only those equations.
I have no such luck. I wish a SRAM could smoke when a pointer address overflows, or a diode with too much overshoot could scream in pain so I could get the failure at once.

I must be jealous: using far more maths than you every day :-(

 

[MikeHalloran]

The up side of not being able to see electrons is that you don't get a lot of unsolicited pseudo- technical help from management.



Mike Halloran
Pembroke Pines, FL, USA

 

[GregLocock]

"I am curious about how comforable they are with us non-engineers running FEA? Are they confident that we are professional enough to refuse work that is beyond our ability? We are being told such great things about the FEA. Can they be held responsible if we decide we are qualified to analyze pressure vessels or high, elevated platforms?"

I think that the trend of bundling crippled FEA programs with solid modelling programs will last until the first significant court case.



Cheers

Greg Locock

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