CAD in creative design, problem solving
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From: Existential Angst on 18 May 2010 10:12 "Cliff" <Clhuprichguesswhat(a)aoltmovetheperiodc.om> wrote in message news:rq05v55kscqsferg90oqblmif5apmirhcg(a)4ax.com... > On Mon, 17 May 2010 14:52:08 -0700 (PDT), Jim Wilkins <kb1dal(a)gmail.com> > wrote: > >>On May 17, 1:26 pm, "Existential Angst" <UNfit...(a)UNoptonline.net> >>wrote: >>> "Jim Wilkins" <kb1...(a)gmail.com> wrote in message >>> On May 17, 12:41 pm, Tim Wescott <t...(a)seemywebsite.now> wrote: >>> > Existential Angst wrote: >>> > > ... >>> > > Ito of the actual function/design of mechanical parts, has anyone >>> > > actually >>> > > solved a "design problem" using CAD? >>> >>> http://en.wikipedia.org/wiki/Finite_element_method >>> >>> Funny, how calculus (the integral) is in fact the result of FEM, in the >>> limit as x --> 0, but done analytically (power rules and all that). FEM >>> is >>> kinda like calculus in reverse, when analytic solutions are not >>> possible. >>> >>> http://www.youtube.com/watch?v=Bt6Q_pVxwl0 >>> >>> Nice. But I would distinguish CAD from this type of analysis/animation >>> program. >>> -- >>> EA >>> >>> jsw >> >>Take that sample truss and adjust the element dimensions until all >>areas are the same color under load. > > Why not just solve a fairly simple problem in Mechanics ? Because "redundancies" in structural mechanics render a simple looking problem not so simple, in fact unsolvable analytically (at least with traditional analytic methods), thus requiring numeric methods. Ergo the finite element analysis et al in that wiki link. -- EA > >>I've been using electronic design CAD programs for ~25 years. >>Simulation, analysis and rules checking are essential components of >>them. >> >>jsw > -- > Cliff >
From: Existential Angst on 18 May 2010 10:15 "Jim Wilkins" <kb1dal(a)gmail.com> wrote in message news:81b58480-139a-4f61-aa49-25fdfc7393e0(a)o1g2000vbe.googlegroups.com... On May 17, 1:26 pm, "Existential Angst" <UNfit...(a)UNoptonline.net> wrote: > "Jim Wilkins" <kb1...(a)gmail.com> wrote in message > On May 17, 12:41 pm, Tim Wescott <t...(a)seemywebsite.now> wrote: > > Existential Angst wrote: > > > ... > > > Ito of the actual function/design of mechanical parts, has anyone > > > actually > > > solved a "design problem" using CAD? > > http://en.wikipedia.org/wiki/Finite_element_method > > Funny, how calculus (the integral) is in fact the result of FEM, in the > limit as x --> 0, but done analytically (power rules and all that). FEM is > kinda like calculus in reverse, when analytic solutions are not possible. > > http://www.youtube.com/watch?v=Bt6Q_pVxwl0 > > Nice. But I would distinguish CAD from this type of analysis/animation > program. > -- > EA > > jsw Take that sample truss and adjust the element dimensions until all areas are the same color under load. I've been using electronic design CAD programs for ~25 years. Simulation, analysis and rules checking are essential components of them. ================================================= I should have specified D = drawing in CAD. :) Analytic/animation type stuff certainly can be useful where D = design, but this is a bit more sophisticated than doodling on a screen. :) :) -- EA jsw
From: cncmillgil on 18 May 2010 20:01 On May 17, 8:28 pm, Kirk Gordon <k...(a)gordon-eng2.com> wrote: > Existential Angst wrote: > > Awl -- > > > In a pointless response to the Village Idiot (Jon Banquer, unemployed > > ex-thief of Qualcomm, in his absurd notion of him asking difficult Qs), I > > brought up the notions of CAD being more for communication than the design > > process itself. > > Bonkers of course confuses "difficult" with "rancorous". > > > Some refinements of the design vs. communication notion. > > > In "art" type design, like, say, for a new car body, certainly CAD could be > > useful, as a simple curvature of a line can alter the visual effect in auto > > design.. > > But this is more of an "illustrating" context than say a parts/machining > > context. > > > Ito of the actual function/design of mechanical parts, has anyone actually > > solved a "design problem" using CAD? > > And by design problem, I don't mean radius blends, geometry problems, etc, > > for which CAD can really shine, but rather the solution to a "how do I do > > this" engineering-type problem. > > > For me, the problem is always solved on paper, the essence of the design > > clearly present on a napkin. > > CAD, for me, is just for telling other people where the holes go, or for > > keeping track of the history/evolution of a design.... > > > Now admittedly, for things like carburetors, these holes can get perty > > complicated, and mebbe CAD would be useful in doping a few things out in > > something like that, but I would think mostly it's a tool for > > communicating/building, not really thinking per se. > > > After all, some perty complicated carburetors were built before CAD, and I > > don't know that CAD really improved them. > > > But mebbe they did. > > > Opinions? Experiences? > > Think really big napkins. Endless, boundless napkins, if you like. > Think about being able to draw a perfectly straight line, or a > perfectly round circle, with just a flick of your wrist. Think about > being able to undo a doodle that looks wrong; but without having to > scribble over it and mess up the whole deal, or without losing time and > train-of-thought when the napkin's full of ink and you need to start > over. Think about being able to pick up one of your doodles, right off > of the napkin, to turn if over and see if it still looks right. Think > about having all your napkins saved in one drawer, so you can easily > find an old one and compare it to something new you just thought of. > Imagine that, almost by magic, all your doodles and scribbles are done > at the same scale, or can be made to scale the same, so that any > collection of doodles can be put onto the same napkin for comparison, > brainstorming, or thought experiments about the project or problem. > > Think about this, too: The first step to solving any problem is to > state the problem accurately and effectively. I find that having the > immediacy of napkin sketching combined with the precision of a CAD > drawing can make the problem itself more visible, which often makes it > more soluble. What's important is not to let the drawing become a > source of delay and distraction that messes up your thought process. > > The reason most CAD users, including me when I was new at it, have > trouble "thinking" with a CAD system is that the mechanics of using the > system get in the way of dreaming and imagining and squeezing thoughts > out of your brain. When a thought appears in your mind, you want to > CAPTURE IT, not go looking for the right command icon, then trying to > make up numbers or mouse-clicked positions that you don't even have yet, > and then extending and trimming and coloring and layering and more, just > to sketch something rough and simple. By the time you've done all that, > the fleeting thought that you were grasping for is gone. > > The solution is not to limit your CAD system to "after-the-fact" > refinement or presentation of a napkin-sketched idea; but to become as > fluent and comfortable with it as you are with your pencil. Then you'll > be BETTER able to play with ideas, and the mechanics of CAD system will > be less limiting than the inaccuracy and messiness and size constraints > and coffee stains on your napkin. When lines and circles and points of > intersection and tangency flow from your mouse the way doodles now flow > from your pencil, you'll think better, more easily, and more effectively. > > To accomplish that level of comfort, you'll need two things. One, a > CAD system that's easy and comfortable to use, and to get thoroughly > used to. And two, lots of practice. Not necessarily structured > practice; but the same kind of constant endless doodling that you now do > on paper. > > One of the reasons I still use AutoCAD Light '97 for much of my > design work (despite JB's endless rants about how idiotic I am) is that > I like it's UI, and I've spent so many zillions of hours with it that I > can can capture ideas using only my fingers, and without distracting my > brain. The CAD system is as natural for me as a pencil, but much more > effective. I don't need to think about drawing; but only about what to > draw. And when I get even the roughest sketch onto my screen, it's a > better sketch, more useful, and more easily played with, than anything I > could do on a napkin, notepad, or drafting board. It's also more > immediate and spontaneous than what I do with more capable CAD software, > which still demands my attention for its own needs. 3D shapes? Fitting > things together? Test assemblies that actually look like they might > work? Later. First I gotta get this thing working in my head. My old > and outdated AutoCAD does that for me like no "stronger" system ever has. > > I once attended a dinner party for a club that my wife belonged to. > She knew all the other club members, but I knew nobody; and even my > wife didn't know any of the spouses. While sitting around a table of 10 > or 12 people, enjoying coffee after dinner, talk turned to something or > other that some folks had questions about, and others offered to > explain. Instantly, three people at the table, including me, reached > into our coat pockets, pulled out our pens, and moved our coffee cups > off of the paper napkins they'd been served on. My wife laughed out > loud. "You can always tell the engineers in any crowd," she said. > "They can't talk or think without a pen or pencil." > > And she was dead right - about the people at the table, and about > the general observation. Thinking - especially the kind involved in > design work of any kind - necessarily involves capturing what we "see" > in our minds. We need to grasp things that would otherwise slip away, > store them outside our heads so our minds are free to keep running > forward, and then look at our ideas as a way to understand them, > manipulate them, and begin hunting for possibilities our original > thoughts had only promised; but not made clear. > > Getting ideas onto paper (or screen) really is a critical part of > the process. Napkins have their virtues, therefore. But so did > slide-rules, and for many of the very same reasons. When was the last > time you used a slipstick, even for rough calculations or estimates? > > Pick a CAD system you can learn to use without effort, that you can > play and doodle with. Save the high-powered software for later. You'll > be amazed at how many napkins will be spared, and how much more robust > your thought processes can become. > > KG Readers Digest version: Industrial Engineers usually come up with the concept design for a product. The look, shape "feel" of the part with direction from the all mighty "Marketing people". That shape = CAD data is then passed off to other specific engineers to design the internal "guts" & fine details of the parts required to still maintain the original aesthetics from that Industrial design. Having that info in CAD data IMO is very important for down stream work now days. Most all solid modelers are "napkin sketchers" Paint type programs are ok just to convey idea's but eventually it should go to a CAD system. So why not skip that time used in Paint Brush or Paint Shop Pro & go right to CAD modeling? That way there's no misinterpretations as to the intent. You've got something more than a pretty picture. SLA's can be made , prototype parts can be machined off of that CAD data. No physical detail drawings are really required until the product is released for production. Accurate renderings can be made from any viewing angle to please those marketing people & do power point presentations for the "big guys". High end graphic arts software like Corel Draw & Adobe are slick & able to export DXF files. But using that software efficiently is a whole other profession. Heck we're machinists here, I'll stick with solid modelers any day of the week, unless of course you want to paste a foil beanie on picture of someone & post it on the net <g> just my 2 cents (now worth about 1cent in this economy) -- ©¿® ~gil~
From: Cliff on 19 May 2010 12:07 On Tue, 18 May 2010 10:12:38 -0400, "Existential Angst" <UNfitcat(a)UNoptonline.net> wrote: >"Cliff" <Clhuprichguesswhat(a)aoltmovetheperiodc.om> wrote in message >news:rq05v55kscqsferg90oqblmif5apmirhcg(a)4ax.com... >> On Mon, 17 May 2010 14:52:08 -0700 (PDT), Jim Wilkins <kb1dal(a)gmail.com> >> wrote: >> >>>On May 17, 1:26 pm, "Existential Angst" <UNfit...(a)UNoptonline.net> >>>wrote: >>>> "Jim Wilkins" <kb1...(a)gmail.com> wrote in message >>>> On May 17, 12:41 pm, Tim Wescott <t...(a)seemywebsite.now> wrote: >>>> > Existential Angst wrote: >>>> > > ... >>>> > > Ito of the actual function/design of mechanical parts, has anyone >>>> > > actually >>>> > > solved a "design problem" using CAD? >>>> >>>> http://en.wikipedia.org/wiki/Finite_element_method >>>> >>>> Funny, how calculus (the integral) is in fact the result of FEM, in the >>>> limit as x --> 0, but done analytically (power rules and all that). FEM >>>> is >>>> kinda like calculus in reverse, when analytic solutions are not >>>> possible. >>>> >>>> http://www.youtube.com/watch?v=Bt6Q_pVxwl0 >>>> >>>> Nice. But I would distinguish CAD from this type of analysis/animation >>>> program. >>>> -- >>>> EA >>>> >>>> jsw >>> >>>Take that sample truss and adjust the element dimensions until all >>>areas are the same color under load. >> >> Why not just solve a fairly simple problem in Mechanics ? > >Because "redundancies" in structural mechanics render a simple looking >problem not so simple, in fact unsolvable analytically (at least with >traditional analytic methods), thus requiring numeric methods. Ergo the >finite element analysis et al in that wiki link. The statemnt was until all areas are the same color under load" which implies similar stresses. What safety factors to use? Which failure modes to account for? As far as the specific issue goes it's still just simple Mechanics IIRC & AFAIK. Slide-rule stuff <g>. -- Cliff
From: Cliff on 19 May 2010 12:11
On Tue, 18 May 2010 10:15:36 -0400, "Existential Angst" <UNfitcat(a)UNoptonline.net> wrote: >"Jim Wilkins" <kb1dal(a)gmail.com> wrote in message >news:81b58480-139a-4f61-aa49-25fdfc7393e0(a)o1g2000vbe.googlegroups.com... >On May 17, 1:26 pm, "Existential Angst" <UNfit...(a)UNoptonline.net> >wrote: >> "Jim Wilkins" <kb1...(a)gmail.com> wrote in message >> On May 17, 12:41 pm, Tim Wescott <t...(a)seemywebsite.now> wrote: >> > Existential Angst wrote: >> > > ... >> > > Ito of the actual function/design of mechanical parts, has anyone >> > > actually >> > > solved a "design problem" using CAD? >> >> http://en.wikipedia.org/wiki/Finite_element_method >> >> Funny, how calculus (the integral) is in fact the result of FEM, in the >> limit as x --> 0, but done analytically (power rules and all that). FEM is >> kinda like calculus in reverse, when analytic solutions are not possible. >> >> http://www.youtube.com/watch?v=Bt6Q_pVxwl0 >> >> Nice. But I would distinguish CAD from this type of analysis/animation >> program. >> -- >> EA >> >> jsw > >Take that sample truss and adjust the element dimensions until all >areas are the same color under load. > >I've been using electronic design CAD programs for ~25 years. >Simulation, analysis and rules checking are essential components of >them. > >================================================= > >I should have specified D = drawing in CAD. :) >Analytic/animation type stuff certainly can be useful where D = design, but >this is a bit more sophisticated than doodling on a screen. :) :) Some might go as far as to use the basic structural formula stuff in "Machinery's Handbook". Others mght use Mechanics & (as needed) calculus & computers & linear algebra. -- Cliff |