The pin router in action.
As CNC machines have become more prevalent, how much have they changed the building process?
“The Ballad of John Henry” looms large in the annals of American folklore. Versions of it have appeared in a number of narratives, usually referring to Henry as a “steel-driving” man who dies from the effort of defeating a steam drill machine designed to replace his ilk. Henry, who cuts holes in stone for dynamite with his hammer and chisel or alternately pounds railroad spikes, represents a way of life threatened by a powered machine.
In this clash between man and rising technology we are reminded that the fear of progress is an age-old battle that humans have fought with every advance in tools. So goes the advent of computer numeric controlled machines. Commonly referred to as CNC, these machines can be routers, saws, welders, or any number of robotic machines programmed to do heavy, repetitive work—the kind that killed John Henry.
At first, these machines were so huge and expensive that only large companies could afford them. The software alone could run into five-figure sums, locking out even medium-size operations. In recent years however, the cost of smaller machines has dropped to the point where even hobbyist builders can afford to put one in their garage or basement shop. Yet in the minds of many guitarists, the purity of a handbuilt instrument elevates it to a higher standard. But what is really the difference?
A century ago, guitars were made primarily with hand tools. But by the 1940s, guitar factories used large cutting machines, like shapers and routers, to perform the basic forming of bodies and necks. A staple of the guitar-building trade was the overarm “pin” router. Along with its cousin the profile shaper, it simplified and accelerated the manufacture of instruments. The pin router is extremely flexible and can be used for hundreds of woodworking tasks. The tooling used to create repeatable parts can actually be made by the machine itself by copying an original form, such as an existing guitar body or pickguard.
Other advances in guitar manufacturing have included specialized machinery that followed physical templates to carve necks or create the archtops on bodies. Gibson famously used both these machines, which were originally conceived to make gunstocks and chair seats, respectively. Guitar factories employed multi-head drill presses to drill six tuner holes simultaneously, and mechanized glue spreaders replaced brushes and bottles. Each of these changes increased output and reduced the amount of hand skills required to make a profit. It also ushered in a new level of standardization that reduced human error. Today, a single CNC machine can do all of the above and more.
“Guitar factories employed multi-head drill presses to drill six tuner holes simultaneously, and mechanized glue spreaders replaced brushes and bottles.”
Just the same, there has always been a subset of guitar makers that rely mostly on hand tools. I find it to be the most satisfying part of what I do. For decades, small builders have existed alongside the behemoths as a way of providing the short run or custom work that a large factory couldn’t afford or be bothered to do. The rising success of small builders who focused on handwork paved the way for large companies to create their own in-house custom departments. Now, the versatility, lower cost, and smaller footprint of CNC milling machines allows both types of shops to do a variety of modifications easily and profitably. So, what does this mean for the customer? Do robot machines suck the soul out of an instrument?
The way I look at it, there is a similarity between all means of manufacture. In the case of the shaper and pin-router era, designs had to be drawn by pen and paper, then transferred using hand tools into physical templates. At that point, an operator loaded a wooden blank onto a fixture and muscled it against a spinning cutter along a path determined solely by the template. The creativity and craftsmanship ended before the wood ever saw the blade, and the operator was mostly muscle. In CNC manufacturing, the designer’s pen and paper is replaced by the mouse and computer screen. The nuance of the procedures are determined in the design and tool-path phase long before someone on the shop floor loads the blank and pushes the start button.
The truth is that every instrument is made using some kind of tool, and automated equipment only does a small part of the job. A seasoned builder can spot problems (and opportunities) before they occur, which machines can’t do yet. There is still a huge amount of handwork required to turn a CNC creation into a guitar. If you think that wood, plastic, and steel goes in one end of the machine and a finished instrument comes out of the other, you haven’t been paying attention. It’s just that now electric motors are the muscle instead of John Henry.
Is it a bad thing if a machine can crank out labor-intensive parts in a fraction of the time, do it perfectly,
and save wood while doing so?
Mark Dalton explains why the CNC machine is the most important tool in his small operation.
For the first nine years that Huss & Dalton was in business, we did things pretty much exactly the way a one-person shop does, with the exception of sometimes doing larger batches of parts for our small-production situation. We did, however, lust heartily for the advantages of a CNC (computer numerical controlled) machine in our shop and began to save our coins and investigate a bit.
In the summer of 2004, we finally took the plunge and took delivery of our Fadal 4020 CNC and Mastercam CAD (computer-aided design)/CAM (computer-aided manufacturing) software package. We had to modify a building to house the massive beast and install an extra air compressor and wiring, so this was no small undertaking.
We were aware that some customers who viewed us as more of an elf-in-a-tree type of operation would not embrace the idea of Huss & Dalton as a CNC-aided shop. But, we were convinced that the benefits far outweighed the negative stereotype that's often associated with the “evil" CNC machine.
Learning Curves
After setting the machine up and then standing around scratching our heads for a bit, it was time learn the software and get the thing running. Jeff Huss and I knew that we couldn't afford to pay a software engineer to work here full-time, so we decided that one of us needed to learn to program the machine. Since he had small children at the time and I had none, I volunteered to take on the task, and set forth by enrolling in some classes at our Mastercam dealer.
I soon found out that this was going to be both one of the most challenging things that I'd ever done, and one of the most interesting. When I finally got up the nerve, I drew a basic program to try out and started the up machine. To my surprise, it did exactly what I had told it to do and we were off. I then started writing programs for some of the simpler tasks we thought the machine could do better, and later worked my way to some of the more complicated 3-D parts like bridges and necks. It wasn't long before I had a new appreciation for the intricacies of the steel-string guitar. It's interesting to note that even though we call them flattops, almost no surface of a guitar is actually flat. Even the underside of a bridge, for example, has a built-in radius.
Fail-Safe Sidekick
I should first debunk the myth that a CNC machine drastically speeds up guitar making: It doesn't. The main tasks that take up most of our time—such as building and binding the body, and all the work that goes into finishing, buffing, and setup—are not the ones the CNC can do. What the CNC can do—and do very well—is make extremely accurate parts every time you ask it to. And make no mistake, starting with perfect and repeatable parts every time not only makes our jobs easier, it makes the guitars better in some ways.
In removing some of the possibility for human error when making parts, we save quite a bit of wood. The CNC machine doesn't make errors on parts as long as the part stays attached to the machine's bed. We use a vacuum system for much of the clamping, which allows us to machine all the way around a part.
We also use the CNC to make jigs and fixtures for the shop, and we remade all of our body molds and side-bending forms. Having perfect molds does speed things up some since we no longer have to spend valuable time tweaking the bodies to remove any possible errors. The bodies come out square with accurate centerlines, which allows the builder to spend more time on the critical job of binding the body.
What CNC Means for the Buyer
If the CNC makes any real difference to the guitar-buying public, it might just be that the larger companies are able to turn out larger numbers of instruments with the machine, keeping the cost of some pretty great guitars pretty low. This is not to say that some of the finest guitars in the world aren't being made without the use of CNC. The machine is just another tool, nothing more, and the luthier must still use each tool to best effect in making your guitar.
The machine is not an evil thing. In the end, it really doesn't matter if your guitar's bridge was handshaped by a guy standing at a belt sander for an hour or if the CNC took two minutes to do the same task. It only matters that the bridge was made well, right?
Even though we're one of the smallest guitar companies out there with our own machine, it has become an invaluable tool to us. If we lost every tool here and had to start over tomorrow, the first thing I'd want to buy is another CNC.
Until next time: Pick up your guitar, play, and enjoy!
From brain to computer to CNC, we follow the life of a Washburn electric
Mundelein, IL (May 1, 2008) - The company that pioneered large scale guitar production in America more than 100 years ago continues to use technology to maintain consistency while utilizing human hands for the more delicate aspects of guitar building. In this video clip, designer David Vogel shows you how multiple computer programs are used to design a guitar body and program CNC operations.
For more information:
Washburn Electric Guitars
