Engineers and CAD 7

[Hurricanes]

I am curious about engineers general relationships with CAD across various industries.

Personally, I have been involved in the energy, industrial and mining sectors. In all cases I had not touched CAD. It is seen as a waste of resources for an engineer to use CAD when you can get a drafter/designer to do it at a much lower cost.

The closest I have gotten to it is when I get a drafter to export a model over for me to do an analysis on it.

It sort of surprised me to see on this site guys with sigs that have something like Professional/Design Engineer and then the version of the CAD package they are using. I realise that in some industries such as manufacturing it is advantagous to have engineers using CAD, but to what extent?

There have been threads here about engineers worried about becoming 'CAD jockeys', or drafters bascially. I guess this is just so far removed from my experiences I was just after other peoples experiences and thoughts with regards to engineers and CAD.

Ok, I know similar threads to this one have been discussed, but they all seemed to be closed when I searched for them.

 

[ewh]

I don't know of any CAD translator which can handle associative drawings. Printing them out is what we do also.
Do you have the latest Solidworks? It should be able to open UG parts directly, though we have had problems with larger and more complex UG files.

"Good to know you got shoes to wear when you find the floor." - [small]Robert Hunter[/small]

 

[calguy07]

I hope this won't be thread jacking, but I started as a drafter (even though I had an MSEE) and worked my way up to designer with the assumption that I would someday get to "celeb" status (ie engineer) and I have no problems with this at all. In my company, you're hired and retained because of your willingness to go this route. In my opinion, you bring little value immediately to a company if you're coming right out of college; the ability to draft well and efficiently was my way in. I worked my way up to designer (which is where I still am). I also don't see myself falling to the trap of being "stuck" here unless it is what I wanted.

I'm also not entirely convinced that its a waste of resources to have designers do their own drafting. The alternative is to have the designer/engineer do red/green markups and continually go back and forth with the draftspeople. It appears to be far more efficient to have designers do their own drafting and do the checking between themselves.

 

[FeX32]

Engineering and "designing" are different


Fe

 

[ewh]

The alternative is to have the designer/engineer do red/green markups

Not necessarily. There used to be Checkers hired for this, and this only. Passing mark-ups between engineers or designers serves poorly compared to having someone whose entire focus is to ensure drawing quality, and tends to let mistakes propagate and become "legitimate" (since few doing the checking know any better).
I have seen engineers who are very well qualified in the tolerancing methods of GD&T make otherwise simple mistakes on drawings. The tendency seems to be "jack of all trades" when it comes to drafting rather than "master of one".

"Good to know you got shoes to wear when you find the floor." - [small]Robert Hunter[/small]

 

[drawoh]

ewh,

I do not see how a master of GD&T can produce useful drawings without a thorough understanding of the design requirements. I would want to have a person sitting in front of a CAD station to have adequate CAD and GD&T skills, and as much skill and knowledge as possible of the design.

Having an otherwise unskilled CAD operator update marked up drawings can be dangerous. Some non-engineering type in production can mark up a print and write an ECR, and the ECR committee can approve it and the whole change can be implemented with the participation of anyone who knows what they are doing.

CAD operators need close supervision by designers and engineers. Much of the time, it will be easier to do the whole job by yourself. If you need to offload stuff, you would be better off hiring a junior designer/engineer, and giving them responsibility for a sub-assembly.

A big threat with mechanical design is that all sorts of people think they are good at it. They will micro-manage the job. They do not want crap from designers and engineers and they may prefer to work with CAD operators. I leave the rest to your imagination.

JHG

 

[ewh]

I quite agree. My point was that there is more to a good drawing than many engineers (who already have enough responsibilities) or even skilled CAD operators (knowing the software is not the same as knowing drafting) are aware of. Stupid mistakes, once approved, tend to be repeated over and over. The mere ability to dimension a view without crossing dimension/extension lines seems beyond most CAD operators these days. I often see "DRILL..." and REAM..." on engineer's drawings.
Engineers have enough responsibilities and shouldn't be saddled with having to concern themselves over seemingly minor details; it is those details, however, consistently applied, that make good, easily understood drawings.
While it would indeed be easier to make the changes yourself most of the time, by doing so you are failing to invest in the skills required of a good drafter, and the situation will not improve.

"Good to know you got shoes to wear when you find the floor." - [small]Robert Hunter[/small]

 

[KENAT]

The 'redlining' of drawings can sometimes be split into two parts. The first part is the fundamental function, here the person review the drawing clearly needs to know all about the function etc. The other part is tolerancing and drawing correctness etc.

For the latter you don't necessarily need to be able to determine the resonant frequency or thermal shrinkage etc. of the part. You do need to know that it mates to 'part B' using x size screws, hole location, hole tolerance etc.

So I have to disagree with you drawoh.

The best checker I worked with was from a designer/drafter back ground not an engineer in the strictest sense. He could do basic stress analysis and the like but certainly wasn't an expert in the field we were working. He concentrated on tolerance and drawing correctness etc. Occasionally had have some input into more 'functional' aspects but usually his functional checking was limited to making sure the parts fit together. He had only the most basic of CAD skills. The other checkers I've worked with have been similar except even less CAD skills. The drawings by the time they'd finished with them were generally a lot better. Once in a blue moon they introduced a functional error but from memory this was only when they couldn't get an answer to questions they asked and had to make their best guess.

ewh, I think on most of this you and I think alike.

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[drawoh]

KENAT,

I am talking about CAD operators with zero expertise outside of CAD. Your checker sounds like he went to a technical school of some kind where he acquired all sorts of expertise with tools and fabrication, as well as drafting. He probably has some design experience too.

Mechanical 3D[ ]CAD software like SolidWorks, is not the least bit idiot resistant. Idiots can destroy the scale modeling that is the basic functionality of 3D[ ]CAD. They can set up parametric relationships that make drawings randomly revise themselves depending on what files the viewer has loaded. They can set up other parametric relationships that break with any attempt to make changes. They can say "Hey, I have COSMOS, I can analyze that pressure vessel!" Even if the designer is not qualified to do critical structural design, they should still have the knowledge and professionalism to know when they are getting in over their heads.

The analysts with graduate degrees probably should not bury themselves in the detailed design. The person who finally does the detail design should be a skilled professional too, in the general sense, not in the sense of being licensed professional engineer.

JHG

 

[KENAT]

Well, there was a previous post about qualifications for a checker. When I was talking about a checker I was talking about someone that meant the more stringent requirements of that list. Having a CAD monkey doing detailed checking is ridiculous. If it's more or less stupid than many engineers doing it is another matter, they wont even spot functional isues, but they'll be cheap;-).

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