Modern Luthiers Embrace CNC for Guitar Building

On the edge of the Pacific Ocean, Santa Cruz, CA, supports a thriving musical community with several luthiers local to the area. It’s here, just a short commute from Silicon Valley’s High Tech Corridor, that amateur guitarist and professional technologist John Bower has married old world craftsmanship with CNC technology. Bower manufactures guitar parts for several professional luthiers with his Tormach PCNC 1100.

“I play classical guitar and several of my good friends are luthiers,” Bower explained. “Since I’ve got a fairly strong mechanical background and an interest in music, I became fascinated with the process of building guitars and my friends encouraged me to try my hand at it. In the process, I learned that luthiers are really stuck in the Stone Age in terms of their techniques for building.”

While Bower didn’t immediately realize the potential for a CNC mill, he quickly recognized the opportunity to improve on manual building techniques. 

“I was trying to bring a little more predictability and a little more accuracy to the building process, so I decided to start building templates and jigs.  In the course of that I purchased a manual mill,” he continued.

“The manual mill turned out to not give the sort of precision that I wanted. A friend of mine suggested I turn to CNC. I knew nothing about it at the time and I started looking around and determined that the only serious player offering any kind of hope of moving things to a light production level was Tormach.”

A self-taught machinist by the most basic sense of the definition, Bower began learning about CNC through local resources in the Bay Area. “Tormach was kind enough to refer me to the Techshop (a local makerspace) in the area. I went and visited Techshop to see the Tormach mill and got exposed to so much more. I was like a kid in a candy store with all the nifty tools they had.” Bower’s computer programming background allowed him to quickly become comfortable with programming his PCNC 1100.

“When I got my machine, I figured there had to be a reasonable way to rapidly get doing something useful by just taking baby steps. I started by looking up what the G-codes were. Because I’m a computer programmer, that was a more logical approach for me as opposed to drawing pictures on a screen and trying and figure out how to get it into CAM and do it that way. For me it was more direct and easier to do it that way than learning the CAD and CAM software. I found it more logical to just say, “You want it to move here and cut that bit there, then do it.”

In a just few short years, Bower has gone from a CNC beginner to a bonafide supplier of guitar parts used by some of the guitar world’s respected luthiers.

“Several parts on the types of guitars that I work with are very difficult to build by hand. The builders that I work with locally asked me to try and develop these parts on CNC so that they would be repeatable and be delivered in some sort of reasonable quantity. I make 30 or 40 of a part and as the luthiers use them up, and then call me up and say they need more,” he said.

One of Bower’s primary customers is internationally-renowned luthier and accomplished guitarist Kenny Hill. Bower builds and supplies guitar bridges and the neck joint (the v-joint where the neck and the headstock meet) for The Signature, Hill’s top-of-the line guitar.

“If you’re looking at the neck of a guitar, right below the tuning machines you’ll see the wood in the neck that has a v-joint. That’s an extremely tricky v-joint because the whole thing is sloped at five degrees on each part. I make both the male and female joint of that part for Kenny and Hill Guitars. It takes about three or four setups on the Tormach,” Bower explained.

“I also make the heel cap, the part where the neck joins the body as well as some of the fingerboards. The fingerboards have a particular teardrop shape to them down by the 20th fret to accommodate an extra reach. So I have to figure out the arching and how to do that cutting, which is done with a very narrow .023 inch end mill."

"My friend John Bower is thinking that we can re-vitalize American small-shop craftsmen with technology, kinda like Henry Ford, and I am starting to agree with him. As much as I love the sensuous hand work of wood and shapes in guitars, I am learning that the difficulties of an employer, the long learning curves, and the simple economics of business, are leading toward CNC and general robotics. There is no substitute for he love of the product and of the pleasure of the work, but streamlining the processes should be a good thing. With robotic technology I may find myself dependent on a different class of worker and tooling, but this is more reliable, and more transferable," Kenny Hill explained.

Hill continued, "In some ways I lament the abandonment of old world hand-work savvy. I take pride in the sensitivity of my hands and my eyes. But in other ways I'm grateful. Although I have to depend on higher skilled tech workers for components, in other ways I don't have to worry about accuracy, and with John Bower–thankfully–delivery times are perfect.

For his part, Bower is just excited to have created a successful small business that also indulges his passion in guitars, “My original goal was to develop a business I could run out of my own home when I retired and sold my own business. I was not trying to create a factory, but rather trying to have something that could be done a little more casually but with precision and being able to produce a good product.

So I started making guitar parts in order really to support my habit of having the Tormach PCNC there for my own hands. It’s turned out to be a reasonable little side business. I’m probably pretty typical of a lot of Tormach owners. I’m not trying to turn this into production, but boy, I’m having a great time doing it.”

For more information on John Bower’s luthier business, contact him at 831-423-2365 or by email at