Charles Fox Bending Machine Revised

In the late 1980’s Charles Fox designed the “bending machine” that most of us use today. Before his innovation, bending the sides of an instrument was difficult and time consuming. Typically, bending over a hot pipe took me about an entire weekend and I always wound up breaking something. So Charles’s invention was a revelation to the guitarmaker’s arsenal.
Charles’s original design was built around 3 light bulbs as the heat source. As a result of the light bulb heat source it was necessary to make the machine quite tall in order to accommodate the light bulbs and the 1/2 guitar form which the sides were to conform to. In my opinion, the machine, as good as it was, was always a bit too tall and awkward to operate. But it was far better than the alternative!
In the 1990’s several different guitarmaker’s discovered silicon heating blankets. These were a perfect heat source for the Fox bender because they could distribute the heat needed uniformly and evenly over the side which was to be bent. This was a huge step forward in the evolution of the Fox bender. This made the addition of an additional press for cutaway production practical. But the machine was still too tall and awkward.

The machine, including a heat blanket, in full configuration now sells on the market for roughly $650.00. Pricey, but probably worth it if you do not want to build one yourself.

In the Spring of 2007, I decided to take a redesign by John Coleman, refine it, and build a "new" style Fox bender. There were several design goals: 1) to make the machine much smaller and still use all of the forms I had made to fit my original Fox bender, 2) to make the entire machine, in full configuration, for under $150.00, and 3) make the design simple enough so anyone with a table saw and a couple of hours could make the machine.

Here are some photos of the completed machine (the drawer, which is very handy, is optional and not discussed in this article). I have bent the sides of several guitars with it and am satisfied that the design is far more comfortable and easier to use than my old machine and, therefore, want to share it with others.

Making the bender:

Initially, here are the parts needed:
3/4” plywood for the main machine (mine was made from scraps found around the shop),
1/4” plywood for the screw press as per the original Fox bender plans,
2 press screws from Grizzly.com. These screws are Part No. H2597 and, as of 7/29/07 they are selling for $13.50 each, much cheaper than what the original design called for,
8 mirror hangers (about $1.00 each) from Home Depot or Lowes. These will act as attachments for the springs and,
Wood or drywall screws 1 1/2” in length to screw the machine together.

Electrical needed:
Heating blanket (Minco)
Timer, Wire and a Plug (Home Depot)

The woodworking parts of the entire machine can be completely made on a table saw with the one exception being the “shoe” for the press. Take a look at the shoe on the Fox plans or a ready made machine for building it. The “shoe” for the cutaway is a 2” aluminum pipe cut to the size of the cutaway.

Initially note that the machine is no longer made with any curved surfaces. That bandsawn design was needed to accomodate the light bulbs. Eliminating that provision allows the machine to be much smaller! The portion which contains the press for the waist of the instrument is nothing more than a wedge shape much like a guitar fretboard. As a matter of fact I cut it in exactly the same way. Initially take a 7” x 18” board and cut a slot 1/4” deep down its’ middle large enough so a 1/4” piece of plywood can slide up and down freely (this will be for the "shoe". Doing it this way eliminates having to make a routered slot in the 2 sides. Now let’s make a “fretboard taper jig” large enough to give us the taper we need for the bending machine. If you do not know how to make the taper jig refer to that article on this site for how to make it. For this article I will assume you know how to do that.

Make a 4” taper jig. That means that it will be 7” wide at its’ widest point (the large end of the fretboard) and 3” wide at its’ smallest point (the nut). Taper the two 7” sides you made earlier. These are the two sides of the new jig with the 1/4” blind slot in each.

Cut two pieces of 3/4” plywood 16 1/2”x 6”. This is the bottom or floor of the jig. Screw the two floor pieces together.

Screw the two sides to the bottom most piece. Make a piece to fit the top. Before you screw the top to the sides, drill a hole in the middle and mount the press screw.
Note in the photos there is an oblong hole through the sides. This hole is 14 1/2” from the top of the sides. The hole is a place which is intended to line up with a large t-nut in the guitar form, holding it in place during the bending process. If you are using the cutaway portion, that is designed to be bolted to the guitar form through these holes. This attaches the cutaway portion AND secures it to the bending form.
Study the photos and the above instructions. Since I do not plan to offer, either here or by mail, plans to build the machine, the purpose of this web page is to give you enough information to make the machine yourself.

When completed and without the drawer, the entire machine is only 18” tall, 7 1/2” wide, and 16 1/2” long. Much shorter and smaller than the original design. IT IS DESIGNED TO USE A HEATING BLANKET-LIGHT BULBS ARE NOT AN OPTION. The blankets can be obtained from a variety of sources including Luthier’s Mercantile, Blues Creek Guitars (John Hall), Minco and Omega. You will also need a heat controller. This is also available from the above suppliers.

When I built mine I kept very accurate details on its’ cost. The machine without the blanket cost me well under $100.00. Depending on where you buy your blanket and controller, the total cost of the machine will be far less than $200.00. Mine was right at $150.00! My thanks to Charles Fox for his original design and to John Coleman who came up with the original idea to redesign the machine!
If all of the above is not clear or you run into a specific problem with the construction feel free to e-mail me and I will do my best to answer!