CAD vs. Paper

"NON LINEAR CREATIVITY" I love that phrase.

 

depends on if you are a cat's people or a dog lover...
or an apple junky or an orange eater or a ford enthusastic or a chevvy friend...

 

These comments bring up another issue entirely that lies within the CAD world. While this particular thread talks about CAD vs. Paper, These comments really look at non-parametric, entity based CAD (AutoCAD) vs. parametric, feature-based CAD (ProE, SolidWorks, Inventor, etc).

The later versions of AutoCAD (it has been a long time since I've been in that realm) have parametric 2D.

If you have never worked with a paremetric modeler, then you will certainly hold the view that most of your CAD time is spent editing. As the name implies, parametric, feature-based modeling allows you to model using real-world dimensional data to define 'features' such as bosses, cuts, lofts, etc. The interesting thing is that these modelers are based moreso on fabrication techniques that have been in use for centuries rather than simple drafting. Just as you would turn a piece of bar stock on a lathe to remove material, you pretty much do the same thing in a parametric modeler. Being parameter based means that your changes are made on the parameter, not on the entities themselves. There is no way in hell I would ever go back to straight 2D drafting in CAD simply because of the fact that the editing is so tedious.

 

yeah and a few hybrids have been known to eat an apple in a chevy but eating my dog is definitely not allowed.

The non linear creativity offers the architect the freedom to continuously improve his brainchild without having to redraw the whole dad blamed thing each time he thinks of a new developement.

Important thing to realize is that at some point the client and builder will have to pick a design and go with it lest you start your project from blueprint "B" and try to finish it using blueprint "F". especially when componants start being cut on cnc machines and the designer forgot to tell anyone he changed a dimension from 5 feet to 5 feet 2 inches. The cnc won't notice but the guy trying to bolt part A to Part B sure will notice.

seems I am hyjacking this thread so I better sit back and lurk awhile. What is my reputation anyway? can't be much worse than it is in real time.

 

Yes Tom, I agree. I have tried a few "totally user friendly" CAD packages (recently FREEship) , and they were extemely incomprehensble.

Last week, I have found a usefull measure and sketch tool that didnt take a week to get some use out of, (free too) - thats Google SketchUp. Used to to design a trailer rebuild. It would be a bugger for boats though.

Check out the online help.

This is one helpfull bit of advice I got from a question I raised

easy hey ???????

Its when you read stuff like that you realise what a foreign language most software packages expect you to master.

For all that, CAD is the only way to go - its just the brain pain involved that puts me off.

 

Car makers still model cars in clay.

 

No they dont. As early as 15 years ago, the Australian designed Ford falcon was sent electronically to the US for approval - the first time they never built a clay model to send over.

Its all virtual reality now.

Thats why
"Toyota introduced the redesigned Avalon in 2005, and ever since it has been beset with problems...... "

http://www.post-gazette.com/pg/06214/710304-185.stm

... and they are not the only company.

 

You know I checked before I posted that and much later than 15 years ago, some of them, were still at it. Google "are they still designing cars with clay."

 

I think you have to see the shapes in your mind, whether you are putting it on paper or into a computer model. If you can't do that, or if you don't know how to build something, you are not going to have a good design. What you are doing with the paper, pencil, or computer model is making a presentation of your ideas so that others can understand what you want them to build.

Hand tools gave way to power tools. Hand calculations gave way to a slide rule, then a calculator, then a computer. I started out on a drawing board in 66, moved to AutoCad in 89 and then to SolidWorks in 97. I used to loft boats on the loft floor and now send 3D files for 5 axis machining.

I think Dreamer has hit the nail on the head when you talk about a parametric 3D modeler VS paper and pencil or 2D CAD. Especially when you add in FEA or CFD capabilities to the package. Even simple draft analysis for molded parts is worth a lot.

CAD tools did not make me a designer/engineer. But I can tell you that keeping up with the current tools is why I am still earning a living at it.

Friends don't let friends design in 2D!

 

We represent things, ideas, in order to communicate them. The purpose of the communication has to be the first consideration. What is being communicated, and to whom?

For example, it is worth remembering that it is not necessary to make a perfect, complete miniature representation of a building, a boat, in order to give all the information necessary to build it.

The medium used for communication (pencil, clay, CAD) is an important decision, not only because of the importance of its appropriateness to the nature of the communication, but because of how well and how efficiently it can express what is in the mind of the author(s)

CAD is extremely good at many things; modelling complex forms, properties, and behaviours, photorealistic renderings, managing complex interrelated sets of information to be used for many different purposes.

Its greatest limitations are currently in the hardware of the human interface. The power of the pencil sketch, or the design model knocked up in card to explore an idea, is their immediacy; there is no interface, no barrier between thought and form. The idea of the line flows unconciously from mind to paper, without interference.

This is particularly important when drawing curves -so much so we will often rotate the paper even, to get the most comfortable flow of line with the restrictions of our wrist and elbow.

We will soon be past this barrier for CAD in 2d - the advent of touchscreen tablets, enabling drawing on screen with a stylus, gives the same immediacy and invisibility of interface that we experience with paper and pencil. No doubt when the ipad lands, we'll start to see much greater penetration of this technology.



The image below was drawn using a tablet computer at a life drawing class.





We have a bit further to go in 3d. Tools which allow the modelling of virtual clay with haptic feedback (touch, pressure; when you push the 'clay' you feel its resistance) are under development, but are still, I believe, fairly clunky.

http://www.dexigner.com/design_news/1045.html



Haptic glove:




So when we've got the virtual clay totally nailed, that only leaves the sensual pleasure of drawing with pencil... the sound of the tooth of the paper cutting the lead... the greasy shine of the graphite, the smell of hot anglepoise...

 

IMHO a specialized hull-creation program is much better than either pencil and paper or a regular CAD program. A nerd with a NURB can get ahead of the lead any day. With a computer I can get things perfect faster than I can get them good enough with pencil and paper.

Having said that, the pencil, scratchpad and mini-dictionary never leave my bedside whereas the computer is firmly relegated to the office by decree of she-who-must-be-obeyed. They are both tools and every tool has its place. In my workshop I have power and hand tools: no way will I grab a hand plane to take 1/4" off a big plank to get a non-standard size. But when I buy a power tool the hand tool remains within reach and always sharp. Like my pencil, which always has lead in it!

Old times are not forgotten. The early computers were awful and I owe the computer a kick or two for damaging some nerves in my drawing hand: I used to get paid to add names and such to important documents using calligraphy ... but these days I have to write left-handed. I recall an old boss of mine reading one of my memos and commenting “do we have a damn monk working for us?” ... a treasured moment.

What the hull design programs do not do is allow one to work backwards. For example when I wanted to design a hull with the simplest possible construction, where the form was driven by implementation rather than by function, it was not possible to get there directly using FreeShip and other, older methods came into play. FreeShip was still handy to get a pretty picture for the end result, though.

 

Parametric modeling is what I was referring to .When I first started I tried Autocad . Its great for producing elevations but as an aid to the creative process its useless. AS for building a physical model and examining it from any angle , a 3d model can not only be examined from any angle it can be seen in any lighting conditions ,at any place in the world ,at any time from the inside and the outside . It can be made translucent and the perspective can be altered to fit the field of view. All its parts can be animated and examined for problems with inter reaction. Its dimensions can be lifted with the click of a mouse and it can be sliced and diced to examine any section. I still build physical models but only because I like to . And I would not build one except in clay unless I already had a detailed plan. I doubt that an artist would attack a block of marble with out a precise plan.

 

We missed an option: anyone still carving half-models out there?

 

I would not want to give the impression that I am at all opposed to computers and their capabilities. I am highly skeptical of many who think that the ability to operate a design program makes them a qualified boat designer. I am very much appreciative of the abilities that such programs bring to those who also skilled in the art of boat design.

I had better have such an appreciation since I will be in the OR in the Heart Institute in Greenville, NC on next Tuesday, Feb. 9. I am further fortunate that probably the foremost practitioner of robotic heart procedures will be my surgeon. He, Dr. Randolph Chitwood, will be doing a MAZE (atrial fibrillation ablation) procedure and a mitral valve repair in the least invasive manner possible. If you want to see something amazing, look at the animated video of the repair procedure. http://www.youtube.com/watch?v=10zEOLISsRE&feature=related

One of the minor analytical tools used was a new stethoscope equipped with bluetooth that transmitted the signal to a computer that analyzed the waveforms and made permanent records. This will probably make many EKG examinations unnecessary.

 

Good luck, Tom