Gibson Guitar’s Newest CNC Machine Strikes A Productive Chord

CNC machines and guitar making go together as well as “Country and Western” or “Rock and Roll.”  In fact, CNC does such a good job at improving the productivity and quality of repetitive wood routing tasks that all of the major guitar makers have adopted it over the past 20 years. Gibson, though, recently took CNC use a step further when it installed a new automatic bandsaw that helps keeps its Nashville factory humming along.

In the past, CNC machines were employed primarily for routing, according to Gene Nix, a Gibson wood products specialist who helped develop the new bandsaw. “We'd been using CNC routers since the late 80's,” he says. “But a CNC bandsaw is a first for the guitar business.”

Gibson installed the new saw, which was built by Warsaw Machinery, primarily for reasons of productivity. In the past, the company's electric guitar necks were manually run through the bandsaw prior to their final shaping. Nix says a good saw operator would get from 200 to 250 necks per day.

The three-axis bandsaw, which works on up to three necks at once, can do “several times that amount,” Nix says. The same logic applies to electric guitar bodies. The saw can handle a stack of three to five body blanks, depending on the guitar model.

As an added benefit, the new saw helped Gibson to adopt a new type of neck blank that is less prone to hidden defects than the lumber used in manual sawing operations.

Nix describes the incorporation of the new saw into Gibson's guitar building operation as seamless. “The biggest challenge was finding a saw that was the right size for guitar building. We looked high and low and there just weren't any,” he says.

So Gibson teamed up with Warsaw Machinery, which has made CNC bandsaws for the furniture industry for about 25 years. These big saws, which usually work on 4 x 8-ft panels with thicknesses up to 14 inches, do have something in common with Gibson's new saw. Both types have a servo-driven x-y table that passes the wood through the saw blade. The third axis is a servo-driven rotation of the blade, whose motion need to be carefully coordinated with movements of the x-y table to allow tighter curved cuts. “It's important to keep blade tangent to cutting path at all times so that there's no binding,” explains Kathy Wettschurack, Warsaw Machinery’s vice president and design engineer.

Similarities with the big panel saws aside, Gibson's bandsaw does break new ground in a couple of ways. The obvious one is its small scale. It has a more modest maximum material size of 60 inches long x 20 inches wide, though it can still handle stock to 14 inches thick. “Scaling down was a challenge,” says Wettschurack. Yet the smaller work pieces used in guitar making did allow Wettschurack to come up with an extremely compact saw design in which the wood passes “inboard” of the blade – meaning between the blade and the machine’s structural column. The larger saws have an “outboard” arrangement.

Less obvious is the fact that Warsaw took an entirely new design approach with the Gibson saw. “In the past, we built everything from scratch,” Wettschurack says, citing linear bearings, actuators, motors and motion control cards as some of the items she would specify on a case-by-case basis. With the Gibson saw, she took a more off-the-shelf approach, picking a pre-packaged motion control system from Parker Hannifin. “We started with their linear actuators because they were compact and fit our profile,” she says. “Then we realized we could get them with the servo motor already attached. Things just dominoed from there.” Wettschurack ended up with a collection of Parker components that include Daedal 412XR and HD185 actuators for linear motion, BE servo motors, Aries servo drives and Bayside gearboxes. Much of it ships to Warsaw pre-assembled, Wettschurack reports.

Wettschurack also went with Parker's PC-based motion control system. She points out that it's G-code capable, which was a must for Gibson given its experience with CNC routers. Control components included Parker's ACR motion card and software as well as HPX PowerStations for the HMI.

Warsaw also used some of Parker's aluminum extrusions to create parts of the machine base, something the company had previously done from welded steel. Wettschurack says that the company will keep the heavy steel bases for its biggest CNC machines, which have higher structural loads than the Gibson machine. But she predicts that the company will use pre-packaged motion solutions on subsequent machines, both large and small. “It was so nice to save the space and assembly time,” she says.

For more on the design of the bandsaw, check out this Design News.