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  • Cheeseking
    replied
    Originally posted by Mcruff
    The beauty of Cadkey, it doesn't need to use coordinates at all, it draws in CAD just like you would on a board, thats the main reason I always recommend it. It cares not where something is, only its relationship to everything else. It will literally run circles around Autocad with less key strokes to boot.
    Cadkey! (good grief is that program still alive??)

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  • Dan Dubeau
    replied
    Originally posted by spope14

    I do firmly believe this though, a person who took pencil drafting and is competent at it will be a better CAD draftsman in the long run, knowing how to find the missing dimensions, and completing a more detailed drawing in the process. The pencil draftsman using CAD will know when a view becomes cluttered or perhaps bogus, and will know that a theoretical point of dimension needs to be dimensioned to be checked in a true form with real tools. I have often in other jobs had to call for corrections or clarification of dimensioning on CAD generated drawings made by someone without pencil background - or line types that are not quite to spec.
    Not to totally disagree with you ( I agree to a point), but I never took any manual drafting classes whatsoever (I'm one of the youngin's.) My design's now are very workable, easy to read, all needed dimensions etc, but they weren't always. When I came out of college, my designs were absolute ****. I still feel bad for the guys who had to build from them (I still work with a few of those guys, and they remind me from time to time ). What made them better, was not manual drafting (though I can really see how that would help a bit) but was to get a better understanding of the various manufacturing processes. What was capable/what wasn't. I got that by talking with the toolmakers, machine operators, and eventually over the years; building the very things I was designing.

    I've worked with designers, and engineers over the years that surely had years of manual drafting experience prior to the cad generation, but were so far removed from the manufacturing process their stuff was so overcomplicated to build. We're working on a project like that right now. Building of an outsourced design. Some details are just so overly complicated it pained me to make them.

    I don't do very much designing anymore, but what I do now is light years better than when I started, and manual drafting had nothing to do with it. I can see how it would have help a little, but honestly I doubt it would have made much of a difference. **** designers are **** designers, whether manual on a table, or cad. The manual ones just go through more pencils....

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  • spope14
    replied
    I have been doing "paper drafting" since 1972 in school, learned it as a career in 1978 to 1980 and in engineering school from 1982 to 1987. During Engineering school I also helped set up the first AutoCad lab at our college, 1983. Been doing them both since DOS, tablet tables, then mouses and such right to touch screen. Most of my drawings are now CAD as ease of changes are superior time wise. Still do Orthographic drawings as well as soild modeling in Inventor, Solidworks, Cadkey, MasterCam, and now EdgeCam. Still have times I go pencil and paper though, sometimes the really small "detail views" can be dimensioned more accurately.

    I do firmly believe this though, a person who took pencil drafting and is competent at it will be a better CAD draftsman in the long run, knowing how to find the missing dimensions, and completing a more detailed drawing in the process. The pencil draftsman using CAD will know when a view becomes cluttered or perhaps bogus, and will know that a theoretical point of dimension needs to be dimensioned to be checked in a true form with real tools. I have often in other jobs had to call for corrections or clarification of dimensioning on CAD generated drawings made by someone without pencil background - or line types that are not quite to spec.

    CAD/CAM is still the best way to do difficult matched arc CNC lathe drawings though, and surfacing, CAD is absolute.


    All said though, making parts by true intuition to fit and without that sketch being updated - using the machining skills is a true art form.

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  • Dan Dubeau
    replied
    I get paid to play with the accronyms on a daily basis (CAD, CAM, CNC, CMM.)

    Everything at work gets a design, or 3d model to pull dimension/toolpaths from. When I do stuff for myself that doesn't involve the CNC and it's all manual work, I rarely do cad work. Just paper sketches, of which I have notebooks full, or just do it straight from NeuroCAD. It's pretty easy for me to visualize and work out complex designs in my head. I sometimes struggle with the math to link it all together and make it work, but that's where the paper, pencil and calculator come in. Very rarely do I do a cad drawing for a personal project, unless it involves the CNC. I think it's kind of a release from work. Cad modeling used to be fun, until it became a job.

    The most enjoyable projects for me are the ones where the computer never even gets turned on.
    Last edited by Dan Dubeau; 09-26-2011, 06:01 PM.

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  • Michael Moore
    replied
    Originally posted by JoeLee
    There are times when I wish I had kept better notes and diagrams on some of my projects.
    I have a spiral notebook with "workbook" written on the cover. I try to put all the notes in that. At minimum it helps to reduce the "what is this scrap of paper?" questions. Unfortunately, it has not completely eliminated those questions!

    I like to do CAD drawings because I have crummy handwriting/printing, and being able to reliably read dimensions is handy. Sometimes my manual math is not so good, and a dimensioned drawing with one hole halfway off the surface can point out that I need to doublecheck that dimension.

    Alibre will automagically generate a 2D drawing from a 3D model, and you can even request it to put in an isometric view with hidden lines and all that.

    As someone mentioned being able to print off a full size paper template can be pretty handy, especially if you want a second template that is slightly different (or one that has a few edges moved out X").

    Paper works well for sketches, but for drafting/drawings I prefer electrons.

    cheers,
    Michael

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  • Guest's Avatar
    Guest replied
    Originally posted by JoeLee
    I have auto CAD here or mechanicle desk top, what evere it is but I really need someone to sit down and get me started on the basics of it. I've played around with it off and on over the last few years but haven't been able to get anywhere with it to where it would be of benifit to me.

    JL................
    The way I learned to draw in AutoCAD was by taking an image of a drawing and setting that image as the background. I then used AutoCAD to trace the image. At the time I was converting old photocopies of building floor plans to AutoCAD files. It makes it alot easier to learn the program if you are not having to be creative with an original part at the same time.

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  • loose nut
    replied
    I believe that was the show I was watching and yes they did do some mockups but they where for PR work, sales etc. not engineering mockups.

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  • Void
    replied
    They do make some mockups, especially of the passenger compartment, just not full mockups.

    Just google for '21st century jet' and you should find the entire program available on google videos and/or youtube. Worth watching all parts of it. It is in five parts. Each just short of an hour.

    http://video.google.com/videoplay?do...31641323350192

    The first mockup is at about 15 minutes in.

    IMO this is the best kind of thing that TV and the intertubes has to offer. The project manager, Alan Mulally (now Ford CEO) is a very impressive character.

    Enjoy.

    -DU-
    Last edited by Void; 09-22-2011, 11:17 PM.

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  • loose nut
    replied
    Originally posted by Magnum164
    Are you sure Boeing built straight from the model without mockups? Mockups are still used even in 3D design from the CAD model.
    Yup! Saw it on, what was that thing we used to watch before the interweb, oh,ya, TV.

    There was a show about how it was designed on a custom made 3D cad system and specifically how they didn't do any mockups, couldn't afford them. The cost of designing and prototyping something like a 777 is so expensive that they couldn't do it. That's why they switched to 3D cad design.

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  • Black Forest
    replied
    What I like about 3D modeling is it is just like machining. Your mind set is the same. You are starting with a block of material and adding features. As I model something in 3D cad build the model the same as I would machine the part. Saves lots of real life materials!

    Here is an example of a 75mm x 75mm x 10mm piece with 8 holes in a bolt circle.



    Now the bolt circle layed out.

    finished part. Less than a minute and if any changes are needed no problem.

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  • Magnum164
    replied
    I am one of the oldies that started out on the board. However, unlike some of the comments I moved easily to the 3D CAD world and also the 2D world. At work, 2D is now reserved to schematics and other simple layouts.

    I use 3D MBD (Model Based Design) and have even started using it in my home shop. What is 3D MBD? Simply drawing a 3D model and using it to drive everything down to the manufacturing and inspection or even technical manuals.

    With a 3D model, you can check assemblies, installations kinematics and one thing I have not seen mentioned is the model can also be used to determine stress loads and actually proof the design before anything is cut. I use it all the time to do simple checks of my designs to make sure they can actually perform as expected. Not good to do a lot of work on a part only to find out a certain area was not thick enough and was over stressed.

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  • Magnum164
    replied
    Originally posted by loose nut
    Modern car and aircraft design is all done on 3D cad without mockups or models being built any more, they cut metal right off of the cad program. Boeing's 777 aircraft was one of the first planes produced this way and they fly OK.
    Are you sure Boeing built straight from the model without mockups? Mockups are still used even in 3D design from the CAD model.

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  • RobbieKnobbie
    replied
    I started on a drafting board in High School, then learned AutoCAD (v2.9!) in college. When I started out professionally we used an entirely different 2.5D cad system, then migrated into SolidWorks.

    I can say, with some certainty, that if you don't learn pen and paper, or at least 2d, first, you tend to make utter garbage in 3d.

    That said, I find I can design a part and make a usable print in SW in less time than it would take me to think it out and jot it down on paper - AND I would typically discover problems in the model long before I start making chips.

    For the hobbiest, I would recomend learnign how to make a usable print on paper, then switching immediately to a solids modeling program. Yes, you'll spend a few hours learning how to use it, but it's fun and very rewarding and before you know it, you'll be looking at a part from the perspective of 'how do i model this' the same as you see it from the 'how do I machine this'

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  • loose nut
    replied
    I also started out on Easy Cad, it was a great simple to learn program (DOS) in it's day and it did everything I needed.

    If you are doing something simple sketch it out on the back of an envelope and go cut metal.

    If you are doing something more complex and are used to drawing at a board then download Solid Edge 2d cad program. It is free and relatively simple to learn and you use it the same way you would an old fashion pencil and paper drafting board drawing, construction lines, views etc. 2d programs are literally a replacement for the pen and paper approach but it is simpler to get a better level of accuracy and you can print out as many copies as you need. 2D is also a good way to generate path ways for CNC equipment.

    If you need to design a object or many fitted objects (assemblies) then 3D is the way to go. You can achieve a level of accuracy and speed that blows the old paper and pencil away. 3D programs are more of a design program then a straight drawing program so they don't operate in the same manner. The learning curve jumps up a lot but the basics can be acquired relatively fast. If you design a part and it "fits" onto another part without any interference, the better programs have ways of checking this, then machine the parts according to the drawings you printed, the parts will fit together first time. Modern car and aircraft design is all done on 3D cad without mockups or models being built any more, they cut metal right off of the cad program. Boeing's 777 aircraft was one of the first planes produced this way and they fly OK.

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  • Paul Alciatore
    replied
    I have done it every way you all have described except the 3D CAD. I learned drafting in high school and the main lesson I came away with was whatever method you used, it MUST be correctable. They required a perfect ink drawing to complete the course.

    My shop also has stacks of pencil and ink sketches. Stacks and stacks. Main problem here is some parts just do not come out right if the drawing is not to scale. Too little space between holes or sides, too thin, too thick, etc, etc, etc. I once made a somewhat complicated custom control panel that way and one section wound up being supported by a 1/16" by 1/4" arm of PC board. I had to add an extra, makeshift support to prevent breakage and I still worried about it's long term viability.

    Many simple parts are just made "on the fly". I do the drawing on the part: it is called "layout". For many things there is simply no time for anything else.

    I use a 2D CAD program for as much as I can find the time to do so. I have used AutoCAD in the past at various employers and was NOT impressed. It may be the "industry standard" but it is expensive and very hard to learn. In short, the only thing going for it is it was one of the first CAD programs on personal computers and has improved little since then. I use a far less expensive program called FastCAD. I bought the simpler version called EasyCAD over 18 years ago and have upgraded many times since. I chuckle when I read about people who have taken two or more classes in AutoCAD: I taught myself how to use EasyCAD/FastCAD and was making a real drawing within an hours of starting with it. There are no classes for it as none are needed. A few minutes and you just start drawing. It has done every 2D drawing I ever wanted in that time frame. And in my opinion, the support is excellent. They have a web board like this one and the head programmer monitors it daily. He discusses problems and actively asks for the opinions of the users. I once posted a problem and he posted a fixed version on their web site the very next day. All registered users could download that fix for free. PROBLEM FIXED THE VERY NEXT DAY! You can't even talk to AutoCAD programmers, much less get a fix from them in less than months or years. And I am not any kind of beta tester or other special relationship with the company, just an ordinary user.

    I do want to get and learn a 3D CAD program as I do feel the need for it on many occasions. I do have a fairly good 3D imagination, but often details can escape me until I start building.

    Which method is best? None and all. It just depends on what you are doing and how complicated or simple it is.

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