15 Replies Latest reply on Apr 30, 2012 5:32 PM by Jerry Steiger

    Need assistance modeling acoustic guitar.

    Richard L

      Hello all,

       

      I am trying to model an acoustic guitar in Solidworks.  I am not even quite sure what to call my "issue," which makes it difficult to search for a solution via this forum or a Google search, so please bear with me if I, for example, posted this incorrectly under the "Surfacing" section of the forums.

       

      What I'm trying to do is create the "binding" on the guitar.  It is the white part along the body of the guitar with the 3 black stripes as seen in this photo:http://www.taylorguitars.com/sites/default/files/400_series_appointments_2.jpg?595

      I'm no luthier, but apparently the binding holds the guitar "top," which is about 1/8" thick, to the body, which is then bound to the guitar "back," also about 1/8" thick.

       

      Questions:

       

      1) What would be a good way to approach this?  Since I assumed the white binding is initially separate from the guitar top, I was trying to make the front of the guitar actually 2 pieces instead of 1.  First I made the profile of the guitar.  Extruding it outward quite easily gave me a guitar top, but then I had difficulty trying to make the binding. One way I attempted it was to use the same guitar profile in a new Part file, but then created a thin extrude (1/8" thick).  Was this an alright strategy?  This looked correct (i.e. imagine making a guitar "cookie-cutter"), but when trying to mate the guitar top and the binding together in an assembly I was getting weird fitment issues.

       

      Is there an easier way to approach it without "faking" it by just having the guitar top one piece and the white binding just being some sort of paint trim along the edge of the guitar?

       

      2.) Related to binding, how would I get the 3-stripe trim you see on the binding?  While the binding, as far as I can tell, serves an actual purpose in the creation of the guitar, the 3-stripes are indeed just aethetics.  What's a good way to make lines like that all along the body of the guitar?

       

      I also have a similar question about the rosette of the guitar (the design/trim around the soundhole), but I feel I can get a good idea how to approach that once I figure out the trim on the binding, since that seems like a similar thing, so that can be saved for a question for another day.

       

      Thanks so much in advance for any help!  I can also post more pictures if desired (real or my SW stuff).

        • Re: Need assistance modeling acoustic guitar.
          Timothy Holman

          I like you post. I build guitars.

           

          For creating the binding I would create that part as an assembly level top down part.  Create a new part in the assembly and use offset and/or convert entities in the sketch to relate the shape and size of your binding to the soundboard of your guitar.  This way if you make any changes to the soundboard these changes will be made to you binding as well. 

           

          To get the differnt colors on the binding I would create split lines on the small narrow surface, then assign colors to the individual faces.

           

          If you wanted to "fake it" you could just use split lines to achieve the look you are wanting to achieve.  Use offset sketches to create split lines around the edge of your guitar model and color the small faces individually. 

            • Re: Need assistance modeling acoustic guitar.
              Richard L

              Heya,

               

              Thank you very much for your reply.

               

              In theory, I think I understand what you mean about having the binding be related to the body of the guitar such that if I were to change the guitar body, the binding changes automatically as well.  That sounds fantastic.  However, in practice, I seem to be having issues trying to accomplish this.

               

              As you stated, I went ahead and opened up a part (my "Guitar Back") in an assembly.  In the assembly, I went ahead and created a new part for the binding.  I copied/pasted the exact profile from the Guitar Back and did offset to make the binding; I then went ahead and extruded that out.

               

              I mated the 2 parts in the assembly file and the fit looked great!  However, now how do I make it so that the binding updates properly with the guitar body if I were to change it on the fly?

               

              Here's a screenshot of what I'm doing.  You'll see that if I change the body (for example here, I drastically changed the cutaway of the body), the binding stays static.  I tried looking into the "Convert Entities" thingy but I don't quite understand it, and the SW Help on Convert Entities feels vague.

               

              Guitar_Issues.jpg

               

              Thanks again for any help!

            • Re: Need assistance modeling acoustic guitar.
              Chris Kamery

              Is this something you are just doing for modeling fun or do you plan on producing your design? The reason I ask, and I will also defer to Tim's judgement on this one as I know only the theories and have never built a guitar, but wouldn't a 2 piece top be an issue? The top and and back plate are the main resonating bodies in a guitar which produce the majority of the sound of the guitar (or other similar stringed instrument). My first thought is that by making a 2 piece top you would disrupt the guitar's fundamental frequency and potentially limit the sound producing capability.

               

              Anyways, just my quick thoughts, I definitely applaud your ambition.

                • Re: Need assistance modeling acoustic guitar.
                  Richard L

                  Oh, I'm just trying to model a guitar just to keep up practice with Solidworks since I only touched it here and there throughout my engineering curriculum in college.  I'm modeling a Taylor brand-name acoustic guitar, so no, I am not trying to design/build my own guitars for my own company, for example.

                   

                  I don't really know anything of acoustics, but what you say probably makes sense.  Again, without being a luthier, I'm not sure how these guitar tops are made, and it's kind of hard to find info. about them--e.g. Taylor doesn't really reveal how they make their guitars haha.

                   

                  What confused me is that, in its spec sheet (for example, this is my guitar I'm trying to model: http://www.taylorguitars.com/guitars/acoustic/414ce#specifications ), it calls it a "binding," and in other areas of the site where it shows off pictures, if you click "bindings" it shows the picture in my very first post.  To me, that made it seem like the binding is indeed a separate component, so I'm a bit confused about this.

                   

                  But you know what? Taking a closer look of the guitar in person (I own it), perhaps this so-called "binding" really is indeed just white trim (for aesthetics) along the edge of the guitar.  Hmmm..

                   

                  In any case, thank you for your thoughts, Chris.

                    • Re: Need assistance modeling acoustic guitar.
                      Timothy Holman

                      I have built acoustic guitars before and the binding comes in long narrow pieces that you glue into a corver relief around the perimiter of the guitar.  So, the actual top or sound board is small than the outside of the guitar a little bit so there is a narrow shoulder all the way around.  The you apply glue and tape the binding into the shoulder and it becomes one with the guitar.

                       

                      Attached is a guitar I built and shows the relief around the top and bottom edge.

                        • Re: Need assistance modeling acoustic guitar.
                          Richard L

                          Ah okay, so the black around the edges in "binding2.jpg" is the binding? Okay, so it indeed is a separate "part," as I originally thought?  Thank you.  By the way, that looks pretty impressive!

                           

                          So anyway, any tips in Solidworks on how to make it so that the binding always contours to the guitar even when I change the body?  (My question/concern presented in my 2nd post).

                           

                          Thanks again.

                            • Re: Need assistance modeling acoustic guitar.
                              Troy Peterson

                              Instead of converting the edge for your path just select the edge for your path.

                              • Re: Need assistance modeling acoustic guitar.
                                Timothy Holman

                                Take a look at the attached assembly.  Look especially at the binding part.  Pease note this is something I through together in just a minute or two so size is most likely very far off just wanted to show you the design intent

                                  • Re: Need assistance modeling acoustic guitar.
                                    Richard L

                                    Hey Timothy,

                                     

                                    Thank you so much for an example; that helps alot and it works how I want!

                                     

                                    However, I looked at it carefully but I just can't seem to quite mimick it.  I have the top and binding mated and what looks like a perfect fit, but I'm missing something.  I noticed that on your spline for your binding, you have a relation for "On edge," and I do not; so far I think that's the only difference between yours and mine, but I can't seem to obtain an "On edge" relation.  I try clicking my binding spine and also control click the edge of the guitar body, but haven't had luck.

                                     

                                    I'll keep trying to mess around with this.

                                     

                                    Thank so much, you've been a great help.

                                     

                                     

                                    EDIT:: Actually, I think I may have gotten it!  I still don't have a "On edge" relation, nor do I have the "In place" mate anymore (though I used to), but for some reason it seems that the binding does update/adjust with the body of the guitar if I were to change that.  I'm gonna continue messing around with this and applying it to my actual guitar model I was working on (I was practicing this on a random arbitrary shape at the moment), and I'll get back to you to let you know how it goes.  Thanks again!

                                        • Re: Need assistance modeling acoustic guitar.
                                          Richard L

                                          Heya,

                                           

                                          Sorry I didn't get back to this thread sooner. 

                                           

                                          Thank you very much for your video, that is awesome!

                                           

                                          However,  I still am having issues with "fitment" now when using Convert Entities.  For example, the picture shows how when I click the face and do a "Convert Entity" after creating a new sketch for a new part in the assembly, the lines of the guitar body get smoothed out.  This therefore causes issues.

                                           

                                          Convert_Entity.jpg

                                           

                                          The thing is, even when just making the guitar back, I notice that after I extrude something, the smoothness of my splines becomes more jagged.  It's like I need a higher polygon count or resolution or...something.  But because of the jaggedness of my extruded body, doing a binding using convert (which smoothens the line out) and then offset, causes things to not seem to fit well.

                                           

                                          Edit: Another picture to show, which includes me adding the sides of the guitar:

                                           

                                          Issues.jpg

                                            • Re: Need assistance modeling acoustic guitar.

                                              Hi Richard,

                                               

                                              You probably already know this but just in case, check  your tools>options>performance>Go to  image quality  and make sure that it is at a appropiate level. You'll always get mismatch depending on how far you are zoomed in, but if you want finer resolution you can up the shaded quality and even turn on optimize edge length.

                                               

                                              Mark

                                                • Re: Need assistance modeling acoustic guitar.
                                                  Richard L

                                                  Wow fast reply!

                                                   

                                                  Thank you for the tip.  I'm looking into it right now.

                                                   

                                                  Now I don't really know anything about how graphics work, but what is confusing is that, given a particular performance/graphics setting of my computer and the software, shouldn't all components be relatively jaggy (or smooth, for that matter, at high quality settings)?  For example, if my guitar body was jaggy, shouldn't my binding (which contours to that body) be just as "jaggy" and therefore actually be a perfect fit?  I seem to be having a jaggy guitar body, but then a much smoother binding, thus having a bad fitment.  Hm.. I'll try to look into it more.

                                                   

                                                  Anyway, thanks!

                                                    • Re: Need assistance modeling acoustic guitar.
                                                      Jerry Steiger

                                                      Richard,

                                                       

                                                      Remember the graphics stuff is being driven by a bunch of software people. They don't think like you and I do. (Kind of like the rest of the sofware!) Perhaps the zig zags of the jaggies are based on the size of the part, so the back has bigger jaggies than the fitting. Even if the fitting and the back are equally jaggy, they may not line up. One is quite likely to zig out where the other zigs in.

                                                       

                                                      Jerry Steiger