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.

 

[kchan711]

A CAD program is like a motorcycle. A kid jumps on it and wants to drive its wheels off and probably get himself killed. On the other hand, a seasoned rider or even a racing professional can do truly amazing things with that motorcycle, pushing himself and the bike to the outermost limits.

So what I am saying is, yes, CAD programs are sometimes far too ambitious to the inexperienced user. But to other capable engineers, wow, they can be liberating.


Kyle Chandler

http://www.chiefengineering.net

 

[Twoballcane]

You can not disregard FEA. Every tool has its purpose. Also, even hand calculations can go awry. I use FEA in two ways. One to correlate my hand calculations if there is no test data available and two to show to management or other non-Mechanical Engineers the problems or solutions because not everybody speaks Mechanical Engineering. Yes I agree that if a user (or not even an Engineer) does a FEA exercise with out hand calculations, you’re setting yourself up for failure, however, coupled with hand calculations, most likely you will be going down the right path. Now for pretty pictures for management and non engineers, I think this is where it comes into play. These are the people who hold the keys to the gate (gate reviews). If you show them equations and theory, they will get confused and lock you out. If they see pretty pictures that show them there is no problem, they will open the gate with fanfare.

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

 

[SomptingGuy]

Try explaining stress concentration to a manager without pretty pictures.

- Steve

 

[Twoballcane]

Oh to add, if stress is not over yeild, try not to show red in your pretty pictures, even thoe red is still below yeild, managment and non-engineers see this as failure. Try to show as green, because green is the color of "go and good".

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

 

[KENAT]

The important thing is make sure the pretty picture is only convincing the 'customer' and not the only thing the person doing the analysis is relying on.

That said there are some situations that are very difficult to do by hand, here FEA may be the only way to attempt analysis prior to testing real hardware.

At previous employer in Aerospace/Defence, the important thing was that things had been validated in two ways, traditionally hand calcs and then tests of hardware in the most critical areas. We were just moving to using FEA to validate the hand calcs for some tasks.

KENAT,

Have you reminded yourself of faq731-376 recently, or taken a look at posting policies:

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

 

[Ztrain1985]

I had a much longer post, but decided my angry rant should not be posted.

1) My college did not teach me any of the fundamentals needed for Power Engineering. Apparently most colleges in the North East US do not.
2) My job has almost no engineering required in it. I have never once, nor has 99% of the Electrical department here ever needed to do a Calc problem.
3) The majority of my job could have been done after taking a basic power course. The challenge is the administrative BS and changing job requirements.
4) CAD is king in this industry. We are critiqued more for the drawing not looking “pretty” then technical content. We have sent packages for review which have received zero technical comments (they missed our mistakes as well). We are encouraged to get something down on paper quickly, and base or thinking off that, instead of thinking about it before drawing it.
5) The majority of my industry lives by “live and learn” philosophy. Most of what I learn isn’t even engineering related, but instead about the history behind something, or information specific to a certain part. I just need to know that X device does this, and I have to wire it like this. There is rarely time or motivation to take it further then that.
6) Everything I do is decided by the NEC. If I cant back it up with the NEC, it doesn’t count. Doesn’t matter how logical the argument is, it all comes down to “What does the NEC say?” (it is not required for Power Utilities, I understand I have to follow it for other jobs).
7) Far too much politics and “social dancing” involved in Engineering.
7) Jobs are often rushed and we have no clear procedure for checking drawings.

 

[SomptingGuy]

And don't forget #7: the job is repetitive.

- Steve

 

[ctopher]

"We are critiqued more for the drawing not looking "pretty" then technical content."

Ugh! My ex-checker moved to the east coast. You must have her as your checker?

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

 

[Ztrain1985]

@SomptingGuy - I have octophobia. There can never be too many 7's

Here is another #7 for you:
Management who wants you to do a certain task (be it CAD or computation via a program) but dont understand/know how to use that program and that what they are asking is impossible.

 

[kchan711]

Ztrain, I have something for you that will make that job just a bit better. Happy reading (also recommended for anyone else with a moron manager).

http://www.dilbert.com/strips/comic/2008-08-17/

Kyle

Kyle Chandler

http://www.chiefengineering.net

 

[KENAT]

Ztrain & Ctopher, speaking as a checker, it's all about clarity of requirement...;-)

KENAT,

Have you reminded yourself of faq731-376 recently, or taken a look at posting policies:

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

 

[lt5q5p]

I have about 6 years of refinery process engineering experience. Some of the previous post range from the funny side to being just scary. It's interesting to read peoples experience from the project design/CAD stand point. Most of my bread and butter is made from improving designs in the field. Often the improvments come from run of the mill type items like identifying inefficient areas. Big improvments are often made by redesigning or retrofitting equipment that was not designed well in the first place. I have assumed until now that these design flaws were mostly just errors that were missed during the design. After reading all of these posts I am starting to wonder if it was just from a poor fundamental understanding of the process. As far as modeling/ fancy GUI's go I have done enough process modeling work to know that it takes time to verify that you aren't putting garbage in or getting garbage out. Just as recently as one week ago I got into a heated "discussion" with a coworker of mine of why his solution to a problem of "just put it into HYSYS" was wrong on several levels. I think he hit a nerve of mine because of my previous experiance with engineers fresh out of school who want to save the world with computer simulations without understanding why they are getting the answers they are getting.