How do you make an advanced, all-metal, crowd-pleasing guitar? By employing advanced materials, precision machining, and additive manufacturing, all in a data-driven production process, according to Klas Forsström, President of Sandvik Machining Solutions. That’s all well and good, but the real test of a manufactured product is its robustness in its intended use.
That is the kind of test Yngwie Malmsteen could provide, a musician known for smashing guitars as well as playing them.
“We wanted to show that we could make it unbreakable, no matter how hard Yngwie tried to smash it. This project seemed like a perfect match for our skills and capabilities—and his,” explained Forsström. The project scheduled its epic test of durability at a concert in Miami, Florida, to see whether the famous rock guitarist could best Sandvik’s manufacturing expertise.
Months before the Florida concert, back in Sweden, Sandvik collected experts in materials, machining processes and additive manufacturing, or 3D printing, from across the company to brainstorm ways to meet the challenge.
Guitars were new to Sandvik. To help understand how to make them, they collaborated with a guitar builder, UK-based Drewman Guitars. “We had to innovate from the top down,” said Drewman designer Andy Holt. “We wanted musicians to say, ‘I have never seen a guitar that’s made like this. We’re confident no guitar has ever been built like this before.’” The final result is a titanium and steel specimen of technological creativity.
“We had to design a guitar that is unsmashable in all the different ways you can smash a guitar,” said Henrik Loikkanen, a machining process developer at Sandvik. “The engineering challenge was that critical joint between the neck and the body that usually cracks on a guitar.”
One step in making that joint was Sandvik milling the guitar’s neck and fretboard from solid bars of recycled stainless steel. It was a guitar design like no other before it. Both the neck and fretboard extended into a rectangular “hub” that would reach deep into the guitar’s body.
To reduce weight, Sandvik hollowed out the interior surfaces of the neck and fretboard, milling down to a thickness of a mere one millimeter in places. Because a scalloped fretboard allows Malmsteen to control notes better, engineers also had to cut away material in long, smooth arcs between frets.
Long, slender components like the fretboard and neck are particularly vulnerable to distortion in the machining process. Sandvik Coromant used advanced simulation software to simulate the task digitally before ever making the first cut. All that planning and simulation led to a process with 90 separate operations, completed without stopping the machines to set up new tools and cuts.
For the body, Sandvik used titanium in a 3D printing process called Powder Bed Laser Fusion. The body needed design freedom, and 3D printing certainly provides that. Complex internal structures, impossible to mill, were built into components to make them light, strong, and flexible. Laying down layers of fused titanium powder 50 microns thick meant the body needed 56 hours to complete. Additional pieces, such knobs and the tailpiece, were created separately using 3D printing and added to the box.
To complete the design, Sandvik also had a unique material it could employ—hyper-duplex steel, a grade produced exclusively by Sandvik. The design sandwiches the hyper-duplex steel in an Isotropic Lightweight Structure, or ILS, between the guitar’s neck and fretboard. Welding was the right choice to join the three pieces. Since welding could torsionally distort the fretboard, Sandvik reached deep into its well of expertise to analyze and test the process to successfully integrate the ILS with the body and fretboard.
The result? Despite his best efforts, Malmsteen was not able to smash the guitar—he could only use it as a tool to destroy speakers and other stage equipment. The guitar itself? It could not even be dented. As Malmsteen himself said, “I gave everything I had, but it was impossible to smash.”
This article was prepared by Sandvik, which is solely responsible for its content.
About Sandvik: Part of the global industrial engineering group Sandvik, Sandvik Coromant is at the forefront of manufacturing tools, machining solutions and knowledge that drive industry standards and innovations demanded by the metalworking industry now and into the next industrial era. Educational support, extensive R&D investment and strong customer partnerships ensure the development of machining technologies that change, lead and drive the future of manufacturing. Sandvik Coromant owns over 3,100 patents worldwide, employs over 7,900 staff, and is represented in 150 countries.