Designing an Acoustic Guitar with Altair Inspire Studio

Inspire Studio is the newest addition to Altair’s Inspire suite of simulation-driven design tools . Inspire Studio introduces a completely redesigned user experience and optimized workflows built with designers in mind. Altair and the Inspire tools are well known for their capabilities in simulation and optimization, and Studio is built to unlock the full power of them by adding the ability to parametrically design models from the ground up. Whether you’re starting with an idea, an image, or an optimized result, Altair Inspire Studio can help bring your concept to life.

As an Inspire user for many years, I’m familiar with the uniform Inspire interface, so I was anxious to get my hands on Inspire Studio when it was released in 2019. After a few months of trying to devote time to learning Inspire Studio, the Coronavirus hit giving everyone more free time at home than we ever asked for. After hours binge-watching TV shows and eating more than I should, the desire to do something more meaningful with my time crept in. Unfortunately, it was still too cold in Michigan for golf, so I decided instead to pick up my dusty, acoustic guitar and learn some of my favorite songs to play around the campfire. The perfect confluence of free time spent playing guitar and new software tools to play with led my engineering brain to create a CAD model of my acoustic guitar in Inspire Studio. What started as a free-time project turned into an interactive tutorial of Inspire Studio’s design and rendering capabilities.

Main Body Creation

I started my project using a planar image of the main body to trace the outline. A few thickening and trim operations later and the main shape was mostly taken care of. I used some simple sketches and curves to define the main shapes of the neck and is where I first encountered Studio’s ability to create flexible designs. I was able to generally create the surfaces I wanted then continuously edit the underlying sketches and observe the effects.

Fretboard  Design

The fretboard of a guitar must be accurately designed to ensure the proper distance from each fret to the endpoints of the strings (bridge and nut). I used a calculator to find the exact distance between each fret location and by using a single constrained sketch, I was able to create individual lines that defined each fret. I then projected those lines onto the curved fretboard and used a sweep to create the 3D profile of the frets. This process was repetitive, but thanks to the CRTL+Space bar command and simple workflows, it didn’t take long. The fret markers were also created using that original sketch to drive proper locations.

Strings and Other Details

Creating detailed areas of the guitar really showcased what Inspire Studio is capable of .  The ability to create mechanical parts like the tuning key bases and nuts and combine them with the free form NURBS shapes seamlessly made creating the tuning key geometry, which is the most detailed part, a breeze. The Control Panel and Guide Bar were essential in learning how to use each tool properly and when they weren’t quite enough, a quick F1 and the Help had all the info I needed.

Rendering

Once satisfied with the geometry, I created a few planes for the floor walls of the room and few extras to set lighting. I was able to set a lot of the materials and texturing on my own using the interactive rendering mode to view changes in real-time.  Once I set up the wood grains and colors, I was able to save them as custom materials to use on future projects.  All the images you see below and in the video are created in Inspire Studio.

Highlights and tips from my experience learning Inspire Studio

• The Tool belt feature is great for interacting quickly with the tools you need
• Read through the keyboard shortcut list and make use of them to change views (1-6), show/hide objects or edges (S, H, I, R, T, Y), or repeat the last command (CTRL+Space) to name a few
• Use the Guide Bar and Help (F1) to learn about each command and what different options are available to you
• When creating basic surfaces like Extrusions and Revolves, look for the option in the Control Panel to create the shape as a NURBS Surface for more interesting shapes
• Use Import Entities while sketching to import features from existing geometry or other sketches to the current sketch to use as a reference
• NURBS Curves are great for creating complex profiles and the Weight option can help to sharpen certain vertices
• When rendering, lighting changes everything, spend time with the lights and the materials will look better

Also, use Texture Positioning to move material textures around while rendering (e.g., wood grain, metal finish, logos, etc.)

Try Inspire Studio yourself with a 14-day free trial . You'll have access to tutorial models and walkthroughs as well as workflows and hints within the tool that are helpful for both experienced and new users alike. 

About the Author

Evan Brennan has been working full-time at Altair since October 2018 but has family roots at the company dating back to 1992 when his father joined the company. Evan is currently an Application Engineer primarily supporting the Inspire platform’s structural and manufacturing solutions. He was a summer intern in a similar role in 2017 and incorporated Inspire into his education making it the focal point of his capstone design project. As a recent graduate from the University of Michigan College of Engineering with a bachelor’s degree in Mechanical Engineering, he is excited to begin his career at Altair!  

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