28 Replies Latest reply on May 7, 2012 5:42 PM by Gerald Davis

    Can SWorks do this?

    John Robitaille

      Hello all -

       

      We have a need to model & simulate a design and was wondering if SW has the capability. To date, no firm or package (that we can afford) has been able to do this.

       

      For simplicity I'd ask you visit our website to get an idea of what we're trying to model; basically a 'piston' traveling helically around a torus.

       

      We first need to insert the constraints, then analyize for interference/fit.

       

      Assuming we get past this the next steps would be FEA and CFD. 

       

      Any thoughts are greatly appreciated!

      - JR -

        • Re: Can SWorks do this?
          Joe Galliera

          I'm assuming first that you would like to simulate the motion.  You can do this in SolidWorks Premium with either the Animation, Basic Motion or Motion Analysis capabilities to handle what you need.  See this post Solvers used for Animation, Basic Motion & Motion Analysis

           

          For the FEA or CFD, that might be a challenge depending on what you are trying to garner from the results.

          • Re: Can SWorks do this?
            Roland Schwarz

            SolidWorks Simulation works well enough IF you know how to work it.  There are more than a few idioyncrasies and outright bugs that do not work as advertised.  (e.g. I have had dreadful results from constant speed motors.)

             

            The caution I would issue with this (or any other) software is that the user needs to be knowledgeable enough to spot results that just ain't kosher.

            • Re: Can SWorks do this?
              Radoslaw Koneczny

              Can SWorks do this?

               

              Yes, you can do this using SWorks tools.

               

              btw its very interesting project

                • Re: Can SWorks do this?
                  John Robitaille

                  Hello Radoslaw, perhaps there is light at the end of the tunnel!  

                   

                  Which modules would be required to do this?  I have had a couple engineers/packages that thought they could, but realized they couldn't.

                   

                  I like John's idea of posting a contest, then we'd be able to KNOW what software can do this!

                   

                  Also, thanks for finding our project interesting!

                  - JR -

                    • Re: Can SWorks do this?
                      Roland Schwarz

                      I don't do contests.  They're usually run by freeloaders who don't value quality work enough to pay for it.

                        • Re: Can SWorks do this?
                          John Stoltzfus

                          Good morning Roland,

                           

                          Some of the projects that were done, weren't done by inexperenced guy's, but I know what you mean, the possibility is there.  I would hope that whoever is paying for the challange does the homework required, same as our customers do. 

                           

                          Great stuff and Robitalille sure has an interesting project to work on,

                           

                          Later,

                           

                          John

                          • Re: Can SWorks do this?
                            John Robitaille

                            Being on the 'freeloader' side of this equation, I feel compelled to comment.

                             

                            I agree, contests can be  'one-sided, the sponsor gets free work, which isn't fair.

                             

                            However, it's the entrant's decision if their time/product is worth the chance, and one would 'assume' quality gets the prize.

                             

                            To me, a contest affords bootstrappers like myself two things: 1 - a venue to get a job done 2- find a contractor who is both capable and cost effective.

                             

                            To me, business is a series 'win-win' relationships.

                             

                            Lastly, the reason why I posted this question in this forum (and others) is to ensure our next CAD package has the capabilities we need. (unlike our current one)

                              • Re: Can SWorks do this?
                                Roland Schwarz

                                On my side, a "win" involves me getting something of value to me, not something the other guy wishes was of value to me.  Cash is king.  Relationships developed through such ventures are not highly valued, as most bootstrappers I dealt with leave behind a long trail of broken promises, unpaid bills, and sad stories.

                                 

                                Also, this is a fairly advanced concept, and will involve many disciplines (thermo, materials, manufacturing).  Any "help" you get needs to be carefully vetted.  The really valuable people are not putzing around with contests, as they have more profitable uses for their time.

                                  • Re: Can SWorks do this?
                                    John Stoltzfus

                                    Good morning Roland,

                                     

                                    Dead on!

                                     

                                    Later,

                                     

                                    John

                                    • Re: Can SWorks do this?
                                      John Robitaille

                                      I can understand the bitterness towards bootstrappers - of course no one works for free. (except the bootstrappers)

                                       

                                      Hence a catch-22. 

                                       

                                      If yooze guys were in my shoes, how would you get quality work with limited monies?

                                       

                                      BTW - this thread was simply meant as a means to determins if SWorks is the package for us....

                                        • Re: Can SWorks do this?
                                          Roland Schwarz

                                          I don't want to discourage you.  I've worked with inventors my whole life (my dad was the archtypical mad scientist).  Since then, I've seen all kinds of ventures.  The romance is gone.

                                           

                                          If I was after what you're after, I would put a lot of work into getting this to a point where I could get some investors interested.  Some investors might even have engineering resources to contribute toward your success.  the best ones are the ones with advice and resources along with money.  They're also the most difficult to persuade, but once they're on your side...

                                           

                                          You are your own most important resource.  Be very careful who you let in.  It's your baby.

                                  • Re: Can SWorks do this?
                                    Radoslaw Koneczny

                                    Which modules would be required to do this?

                                    SolidWorks Premium contains Motion simulation and linear static FEM simulation: so you can build 3d model then use Motion simulation to animate and check parts for accelerations and inertia. With static linear analysis you can check how pressure and temperatures influence housing( deformation stress strain thermal expansion).

                                    Rendering and animation tools will help you to present results for futher reasearch and development.

                                     

                                    Thats all avaiable in SolidWorks Premium package.

                                     

                                     

                                    Regards

                                    Radek

                                      • Re: Can SWorks do this?
                                        John Robitaille

                                        Thanks Radek,

                                         

                                        The consideration isbeing able to simulate, and analyse, the helix around the torrus.

                                         

                                        In Alibre we've derived the helix/torus(H/T) via prametric equations.  But when we extrude a circle around the H/T Alibre can't even make the circle constant.  I contracted an engineer to draw this in SWorks  (attached) and it was even worse!

                                        HOUSING_0.5_6_1_SweptSurfaceSketch1.JPG

                                          • Re: Can SWorks do this?
                                            Radoslaw Koneczny

                                            Extrude along path and guiding curves is one of meny ways to model this shape.  Cylinder can be modeled as extruded circle or rotated rectangle.... etc.

                                             

                                            Doing H/T it in one operation is not always best approach.

                                            Extrude along path and guiding curves is one of meny ways to model this shape.

                                            I always use surfacing to model complex shapes.You shall consider to use diffrent modeling techniques,for example surface loft with cut using surface and modeling 1/3 of your shape first because there is cyclic symmetry every 60 degrees.

                                             

                                            SolidWorks Motion will also generate curves for you

                                            motion-path.gif

                                             

                                             

                                            Well finally answer is yes , SolidWorks can do it and in my opinion there is a lot additional tools that will help you at almost all research and development steps.

                                            no more comments from my side.

                                            • Re: Can SWorks do this?
                                              Jerry Steiger

                                              John,

                                               

                                              Getting sweeps to work well is not the easiest thing to do in SolidWorks, but I don't think what you are trying to do is that difficult. You can probably talk some folks in the SolidWorks/Parts and Features or SolidWorks/Surfacing into giving you a workable model of the geometry.

                                               

                                              Jerry Steiger (who is too busy and far behind to take on any challenges)

                                      • Re: Can SWorks do this?
                                        Bengt Gustafsson

                                        Hi John,

                                        Being a sucker for the somewhat unusual, I just had to try building the model using curves generated in the Motion module, as suggested by Radoslaw.

                                         

                                        It is possible, as you can see by the screen shot. The model was built in this way: Motion setup > Trace path > New part in assembly > 3D Curve, copying the paths > Loft surface between the curves > Pattern 3 surfs > Cutting the solid.

                                         

                                        Problems discovered:

                                        • I could not make the 3D curve parametric. Changing dimensions and re-calculating the motion study crated new paths but would not update the 3D curve.
                                        • The Surface-loft would not go all the way around, had to make several surfaces and knit them. Perhaps adding curves could work - I used 20.

                                         

                                        I am sure it could be done at part level as well, but it was fun trying this method. Never know when it comes in handy.

                                         

                                        I also tried using the path traced by the centre of one piston, to create a sweep in one shot. This did not work well, as the surface ended up with some kinks at several places.

                                         

                                        Good luck with your project.2012-05-06 00-03-28.png

                                        //Bengt

                                          • Re: Can SWorks do this?
                                            John Robitaille

                                            Hello Bengt,

                                             

                                            very impressive  -- I see you like a challenge!   I wish I understood SWorks better to fully understand your tact. 

                                             

                                            By parametric I assume you are talking about importing or linking to a dataset (XLS or..)?  If so we have a XLS that does this so I hope so...

                                             

                                            Unfortunately surfacing is somehting completely new to me, and apprantly Alibre does not do.  However you too have made a great case for Solid Works - guess we have a groups of believers!

                                             

                                            But, wow, for a small shop like us, SolidWorks has a very high entry point!!

                                             

                                            Thank you for your time & excellence!

                                            - JR -

                                          • Re: Can SWorks do this?
                                            Gerald Davis

                                            John Robitaille wrote:

                                             

                                            ...Any thoughts are greatly appreciated!

                                             

                                            As a matter of full disclosure, I have not a clue how your invention works, John.  I looked at your web site but it didn't soak into my thick skull. 

                                             

                                            Blundering ahead anyway, I created the SW12 assembly found in the attached zip file and used it to create the attached AVI - uses Techsmith codec.

                                             

                                            First I sketched a profile of a tri-lobed piston using your web site as a guide.  I also created a sketch for the path of the crank shaft - just a circle.  I used those to create a sweep and twisted it along the path.  I called that the PistonPathSweep.sldprt.

                                             

                                            Next, I created a cylinder part and used the PistonPathSweep to create a cavity in it - that was saved as Cylinder.sldprt.

                                             

                                            Then I saved a copy of the PistonPathSweep as Piston.sldprt and created just a 10mm slice - that leaves the walls in close proximity to the cylinder cavity.

                                             

                                            The crankshaft is just a glass blue blob to indicate something is holding the piston.

                                             

                                            The PistonPathSweep has done its job and is no longer shown in the assembly.

                                             

                                            In preparation for the MotionStudy Animation, I added an angle mate between the crankshaft and the cylinder.  I manually positioned the Piston in the Cylinder for visual alignment.

                                             

                                            The motion study, at my behest, sweeps that angle from 0° to 359.99° in 15 seconds.  I attached a 24RPM rotary motor to the piston.

                                             

                                            Problems: The surfaces of the loft and the cavity are approximations and not suitable for fabrication; the simulation is off by .01 seconds; the simulation does not show friction or actual driving/driven results; the design is incomplete.

                                             

                                            Successes: after about an hour (total) of cadding about we have an animation.  I believe most SW users would find this modeling example to be pretty mundane.  To the extent that this sample reflects your objectives, SolidWorks can do the job.  This is not the limit of the tool - just the limit of what I can do without wearing the wheel off of the mouse.  I make joke; my real limitation was self imposed time constraint.

                                             

                                            If you need help with modeling, I do such for money.  I think I'm pretty easy to find.  If not, please advise.

                                            dbr.JPG