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Thoughts on CAD

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  • Thoughts on CAD

    Just tried Rhino v4. It reminds me much more of 3d studio max than a cad program for machinists. I am sure if I spend time with it, it will grow on me. It looks workable.

    Autocad, the person behind this piece of software needs to be beaten. I don't know about you, but I use a piece of CAD software to help with the design process. I don't know how long this line will be, or what this dimension should be, not until everything is nearly complete and finished in the cad program. If I have to enter lengths and dimensions from the very start, then this would mean that the product would already had been designed.. So whats the freaking point of autocad?
    Turbocad... I bought version 9, it is a total piece of crap. It does not do what I want it to do, simple as that. If I have to get out the calculator and do some TRIG to figure out an angle, then your cad program is a piece of ****...

    Solidworks. I have seen the light, it is a dream come true, one that I cannot afford. You make parts as if you were machining them. Now THIS is the best feature of all. You actually can ALTER a part by editing it's dimensions. Drill a hole and countersink it for a screw. Hmm, too close to the edge? Change the dimension leader of the part, make it .250 instead of .200 from the side. Done, works. I can actually slap something together, fit everything together, run an animation and do a collision detection to check clearances. I can use this piece of software in the design phase, and hell, all phases... I am in love with Solid Works. I wish I was filthy rich, I'd buy a lifetime license. This program is bliss.

  • #2
    Originally posted by BillH
    Just tried Rhino v4. It reminds me much more of 3d studio max than a cad program for machinists.
    It's really marketed like that too: a NURBS (curves) based free-form 3-D modeling tool like 3ds Max.

    Autocad, the person behind this piece of software needs to be beaten.

    Solidworks. I have seen the light, it is a dream come true, one that I cannot afford.
    I've had the exact same experience -- the user interface and flow on Alibre is attrocious. SolidWorks has a 2 year educational license, but apparently the software stops working after 2 years...
    "Twenty years from now you will be more disappointed by the things that you didn't do than by the ones you did."


    • #3
      I think solidworks was the best investment in cad I have made. The program is well worth the cost. You dont have to buy the yearly license agremment but it is nice when they have new releases. SW09 requires a good amount of memory to run. I have 8gig of ram and a mid range workstation video card. SW is great if you have the resources.


      • #4
        You can "free form" model with Rhino or you can input exact values. It will extrude a 2-D curve/line into a 3-D solid or you can extract a 2-D drawing from a 3-D object. Granted it is not Solidworks but it is not as expensive either. You can draw with Rhino and import the drawing into Solidwork as well as read a Solidworks drawing with Rhino.

        Rhino4 has linetypes, linewidths, sheet layout and dimension styles to allow you to do a complete working drawing from a 3-D object or a drawing that you constructed entirly in 2-D. If you import an AutoCad drawing it will import the lines and layer system you set up in AutoCad.

        It also works well with MasterCam and many other CAM programs to write toolpaths. Some of the CAM programs are "plug ins" in Rhino and allow you to change geometry and regenerate the toolpath to correct/change designs.

        RhinoV4 print routines support most of the small lasers very well. The mesh tools work well with the 3-D printers in creating "watertight" art work.


        • #5

          There are many variations in CAD as regards price (initial and on-going) as well as versatility and value for money.

          So far the discussion is more toward the "top end" than not.

          Many may only require a simple sketching package, some may require a "try before you buy" package, others may only require 2D, others 3D, others a modeling package, and others may just require something that they can export DXF files from for use in processing for CNC code.

          The "all-in" cost of CAD is not just the software as there may be considerable other investments in hard-ware and time as well.

          Consequently, people's perception of "value" may not necessarily be just the features in a CAD package.

          Just to "stretch" things a bit, a "High end" package will not make you an expert nor will it necessarily solve all of your problems or meet all of your objectives. Neither, on the other hand will a "low end" CAD package necessarily not meet any or all of those objectives.

          A broader discussion will assist.


          • #6
            Originally posted by oldtiffie

            A broader discussion will assist.
            Well what do I use cad for...

            I use cad for design and layout, from start to finish. I use cad for taking drawings of a live steam locomotive that may have been drawn in metric, I convert it over to imperial inch and redesign it to use standard imperial stock sizes. So I must assemble it in 3d, make sure everything fits, and even simulate the valve motion if I had to redesign any linkages. I have a kozo A3 engine that I drew in Solid works 2006 as a tutorial in learning the software. The results are simply amazing.
            Some times I do simple things like quick design theory. I may need to figure out an angle inside of a triangle and I am too lazy to use trig and a calc, so I use cad to tell me what the angle is. Other times I use cad to design a part for paper printout before I machine it.
            CNC work is in the future, perhaps far future, still need to pay off a 50,000$ loan for flight training...


            • #7
              "I have 8gig of ram "

              Do you need anywhere near that much?

              I use high end IDEAS solid modeler s/w at work and we only have 2 GB.


              • #8
                I've used Turbocad through several versions now. When I first got it, version 9 I think, I just got terminally frustrated trying to use it. I couldn't find all the ropes and handles I wanted to make it do things. That may have been my myopia, because I'd worked on mainframe CAD programs years ago and this didn't have the same command structure.

                Finally I got out their 2D and 3D tutorials and went through them. Seeing the way they built things was the leg up I needed. Once I could kind of see where things were going I could poke around for the additional construction tools.

                Also, I initially treated it like a drawing board, stretching extension lines over to another view just like I would with a drafting machine. After I was reasonably comfortable with that though, I started actually making 3D solids so I could generate any kind of view, projection, section or whatever to get to the dimensioned drawing for the shop.

                Still often I'll often just throw a few lines and circles down to get a feel for proportions, clearances and things if I'm making something ad hoc without a complete design and dimensioned drawings.

                Interestingly, a few years ago I was in a shop for a couple weeks that built custom machines for manufacturing. Some of it was pretty complex indexing table assembly machines and so forth. The owner was a degreed engineer and did all the design, but he never did generate a complete machine drawing set. He'd have an idea to start with, lay out a few weldments, look at places for slides and ballscrews, then print out essentially just a one page sketch of stuff with essential dimensions and take it around to the machinists. By the time they'd have that done, welded, and heat treated (stress relieved) he'd have more sketches of what to machine next. Damndest system you ever saw, but lovely, lovely machines.
                "People will occasionally stumble over the truth, but most of the time they will pick themselves up and carry on" : Winston Churchill


                • #9
                  If the RAM question is in regard to Rhino then the answer is 2 GIG is adequate for most things. If doing some intricate design work then 4 GIG might be better.


                  • #10
                    Originally posted by Stepside
                    If the RAM question is in regard to Rhino then the answer is 2 GIG is adequate for most things. If doing some intricate design work then 4 GIG might be better.
                    If you even want to take advantage of 4gb of ram, you'll need a 64bit OS.


                    • #11
                      Cut my teeth on AutoCAD and I confess I like it. But then I am used to it. Rhino's interface is/was very similiar from what I remeber of playing around with it. SolidWorks, I just never had enough time to play with it and now I don't know if I ever will take the plunge. By the time I get to doing it in CAD I've already worked most of it out on paper
                      Forty plus years and I still have ten toes, ten fingers and both eyes. I must be doing something right.


                      • #12
                        Problem isn't with the program...

                        The problems you expressed with some of the CAD program isn't that the program is so bad, its just that some of the ways to do things aren't very intuitive. I have used Autocad for few years and I use it to whip out a quick & dirty sketch or to go for details in a model design. I can visualize a 3D object ans tehn slap down multiple views with all the internal parts on different layers and in different colors and make modifications and find it a joy to use.

                        Now those various 3D programs are a royal pain - BUT then i have not had much chance to use one and get familiar with it so they MUST BE a royal pain-in-the-drain to use.

                        If I could get my hands on one cheap enough I might try it, but I still have to get my parts to a 2D surface (paper) in order to make it. And I have seen some pretty poor attempts to use a 3D program to produce those 2D prints. It all boils down to how proficient the designer is with the tools he has. You may like your 3D cad, but I can't afford it and I can get things done nicely with my 2D programs. Pick your favorite poison, but be careful about what you say about the other guys program just because yuo have not had time to become proficient.

                        By teh way - In autocad you start out with a few lines, make some parallel lines, some lines at right angles and such just like teh construction lines youi used on paper. Then you delete some, trim some and a drawing appears - kind of like the light pencil drawing that you later inked. (I am old enoughto have done pencil drafting, but no inking...) Don't blast somebody elses tool just because you don't have the skills to use it, be kind of like condemning CNC just because its not manual.


                        • #13
                          I use Solidworks (2008, premium, toolbox, a nice seat) almost every day, it is great sure, but out of the hobby realm for sure.

                          I own Rhino/RhinoCAM Basic, and I agree it will grow on you. I don't know if it was absolutely the best package for the money but I have figured ways to work around every limitation so far. I am happy with the purchase. You can build accurate solid models it is just a different approach. Learning how to do something new is good for your brain too!

                          Is this a business or hobby or is the line to blurry to tell?


                          • #14
                            I use solidworks at work, school, and home. Have used Pro/E, have used mastercam both in brief spurts.

                            I don't really think of any 3d program as a primary design tool, and I don't think many people try to use them as such. They're second-step design tools at best.

                            If I don't know how long I want something major, it's time to get a sheet of paper out and do a hand sketch, or to draw on a bit of bar stock. I draw out what I want, and put the major dimensions on it, or notes on how big I think it should be. After I have a general idea of what it is that I'm making, then and only then do I fire up a solid modeling program. With the major critical dimensions mostly in place, it's then trivial to come up with the other dimensions. But there's got to be a place to start, and that's a hand sketch.

                            But also, similar to what TGTool does, I sometimes use solidworks to figure out dimensions for something incomplete very quickly. That's usually as far as it goes, though.


                            • #15
                              As an alternative to SW you can get Inventor Lite for free, it's similar to SW, they are both parametric modelers and are each other chief competitors, but it has somethings disabled to make it "free", no assemblies and some of the bells and whistle are missing.

                              Toasty, the whole point of these newer 3D cad programs is for designing equipment from start to finish, thats what they excel at. You might sketch out an idea on a napkin but the whole design is done in the cad program. The Boeing 777 was designed on one from start to finish, no paper and pencils or other methods and sent to production without any mock ups or other preproduction work, it's to expensive to do that anymore.
                              The shortest distance between two points is a circle of infinite diameter.

                              Bluewater Model Engineering Society at

                              Southwestern Ontario. Canada