The Fadal

The Fadal

The Fadal ("fuh-DOLL") is a computer-numerical-control (CNC) vertical machining center (VMC) manufactured by Fadal Machining Centers in Chatsworth, California. In a nutshell, the Fadal can automatically machine metal, plastic, or wood using a pattern the user programs with computer-aided-design (CAD) software.

CNC machining is commonly used in large factories. Taylor guitars in particular makes heavy use of CNC machining; the new Taylor neck-body joint would not be possible without the high precision and consistency of CNC machining. A CNC machine of the sophistication of the Fadal is not a tool that you'll find in most small shops because they are expensive (the used one that Jim bought had a final cost, including installation and software, of about $100,000). Jim was inspired to take the plunge and make the huge investment after consulting with Bob Taylor of Taylor guitars, and especially Tom Anderson of Anderson Guitars, a small shop specializing in electric guitars that uses CNC machining. Even with their expert advice, it took several months for Jim to become productive with the Fadal. But the expense and hard work have paid off as the Fadal has helped Jim accomplish things he only dreamed of before he had access to this versatile tool.

This page provides only a quick overview of Jim's use of the Fadal. Future pages will provide much more detailed information about the many tools and fixtures Jim has produced with it. So stay tuned!

Work on the Fadal starts on the 2nd floor, far away from the Fadal itself, on this computer. Using CAD-CAM (Computer-Aided-Design/Computer-Aided-Manufacture) software made by Mastercam, Jim has to carefully program the shapes he wants the Fadal to machine.

In his early months working with the Fadal, Jim got help with CAD-CAM programming from this fellow, Matt Hajicek. Jim says of Matt, "Matt is the smartest guy with geometry I ever met and because of his tutoring I am now able to draw fairly well in Mastercam and do my own programming. Matt now works for Mastercam!"

The programmer has to draw the part to be cut with mathematical precision. This screen shot shows the outline of a peghead and its volute. Colored lines can indicate various cutting paths or layers of the workpiece.

After you draw the piece in "skeleton" form, the software is capable of rendering it in 3D so you can see how it will look. This screen shot shows a bridge.

The Fadal has its own computer that only understands a rather primitive CNC command language. The CAD software produces these commands from the drawing, but they have to be transferred to the Fadal downstairs. Jim uses an old laptop for the transfer. A bit of a kludge, but it works!

Here is another view of the Fadal at an angle that lets you see the many tool bits in a turntable next to the cutting head. The machine can switch from one tool bit to another under program control; part of the job of the program is to specify the right tool at the right time.

Here's a good example of the Fadal in action, complete with tool swapping. In this sequence, a thick bit is being used first to make a rough cut of a peghead and the volute...

...and later a thinner bit is used to refine the shape of the volute. Shapes can be cut to extreme precision starting from very rough materials by moving from course to fine tools in this way.

Here's a great example of the precision of the Fadal. Jim shapes his bridges using the Fadal, starting with a plain rectangular block of ebony. This photo shows the bottom of a finished bridge. Note the very shallow lip around its perimeter. The lip is only a few thousandths of an inch deep. Using a template, Jim finishes the tops of his guitars with laquer that extends under this lip. In this way the edge of the finish is completely hidden when the bridge is finally glued on.

Jim uses the Fadal to cut his necks and bridges. But mostly he uses it, not to cut pieces of guitars, but rather to fashion unique, precise jigs and tools to help him with aspects of construction that cannot be done directly with the Fadal. Here he is using the Fadal to make a wooden jig for holding the sides of a guitar body together during gluing and other operations.

The Fadal can cut metal and plastic as well as wood. Here it is cutting a thick aluminum plate to be used in a jig to hold the top or back of a guitar against the sides during gluing. The plate's surface is being cut with precisely the desired curvature and bevel of the guitar surface.

Here are some plastic forms made on the Fadal for holding braces in the proper position on a guitar top or back as they are being glued in a vacuum press.

This may be Jim's magnum opus with the Fadal. This is a fixture for making the lining ("kerfing") that holds the top and back to the sides of the guitar. To make the lining, a long wood strip is cut with dozens of close "kerf" cuts so that it can be bent around the perimeter of the guitar. With this fixture, four strips are held in place by a vacuum (one strip is shown in place) while cuts are done on the Fadal using a right-angle head to turn the saw blade. Individual channels (each with a rubber gasket) are needed due to air leakage through the cuts. Jim designed and executed this amazing fixture with Matt's help.