Many luthiers cut the neck blank from a single piece of wood. Many others construct the neck from several pieces of wood which are glued together. I believe, as do many others, the the stronger neck is that which is glued to gether from several pieces of wood. In his book, Cumpiano explains the merits of the scarf-jointed headstock and laminated heel block. It only makes sense that this is the preferred method of constructing a neck. Here, I'll show you how I make the neck using the techniques Mr. Cumpiano describes in his book.
One of the only places where I deviate from the book is in cutting the scarf joint. Rather than make the cut by hand, I have been using a bandsaw to make the scarf cut. While this is more accurate than making the cut by hand, the resulting cut still needs to be trued as outlined in the book. Once you make the cut, check it's accuracy with a square. Read the truness of the cut by placing the square in such a way as to check the exit point of the blade. If this cut line is perpendicular to the edge of the neck blank, then your cut is true. Otherwise, it needs to be trued by hand. There is a table-saw solution to this problem as well, and I think the resulting cut is as close to perfect as one can get. Here is a link to a jig made by Pete Licis. This jig looks very promising. I built my version of this jig in about an hour using MDF (medium density fiberboard). With a thin-kerf blade on a properly adjusted tablesaw, a very accurate cut can be made. I also think that this type of jig will allow for new possibilities in the construction of the neck.
A caveat of using the scarf jointed method of neck construction is that the grain pattern reverses itself on the headstock as compared to that of the rest of the neck. This is due to the fact that after the scarf cut is made, you reverse the headstock piece when you glue it onto the neck shaft. In effect, you are seeing the grain as it is on the back of the neck. The headstock gets overlaid with a veneer, and the front of the neck is covered with the fingerboard. Thus, the grain on the back of the neck is in essence the same pattern as that on the front of the headstock. Still with me? Good. Nowthen, with the advent of this tablesaw jig, there is a solution. Measure your neck blank a little longer than you normally would. Crosscut the headstock piece from the blank using a straight 90 degree cut. Then, flip this piece over and clamp it to the jig in such a way that the blade will make a full scarf cut. Do the same for the neck shaft, but don't flip it. What I'm saying is to make two cuts. One for the neck shaft and the other on the inverted headstock piece. If your jig is stable and your clamping is strong, the cut it produces should be very repeatable. Once the scarf cuts are made and you flip the headstock piece over to glue it onto the shaft, your grain will line up perfectly as though the neck and headstock were cut from one solid piece of wood. This is a minor point, but one which has often bothered me when I make a neck from a nicely grained piece of mahogany only to see the grain reverse itself as the eye travels up the back of the neck to the headstock area. Again, as of this writing I have not attempted this operation. By looking at the jig I think it is very feasible though.
Cumpiano uses a mortise and tenon to fasten the neck to the body. I have built two guitars using this method. It is a deviation of the dowel pin method described in the book. Actually, Mr. Cumpiano has described a newer method on his website. The new method uses knock-down connectors, or barrel fasteners rather than dowel pins as in the book. This method works very well to hold the neck to the body. However, as of late, I have been using a simple butt-joint ala early Taylor guitars. This method is quite acceptable and is infinitely easier to create than the mortise and tenon or dovetail neck joint. Following are the techniques I use to execute this fastening method.
Before you shape the heel, you must locate and drill two 3/8 inch holes into which threaded inserts will be installed. The way I locate these holes is rather simple. I make and frame my guitar body prior to shaping the heel of the neck. I have the headblock pre-drilled with two holes through which the attachment bolts will pass. Into these holes, from the outside, I place locating centers. These are small steel plugs which come in a set, usually containing two each of three or four sizes. They fit into the hole, and they have little points on the end which protrudes from the holes. These are used in location dowel holes when performing dowel-joint operations. With the dowel centers in place, I carefully locate the neck on the body, and press it down onto the locating centers. This action places two marks on the underside of the heel. These marks indicate the centers of the holes for the threaded inserts. Drill the 3/8" holes centered on thse marks. If you can, use your drill press for this so that the holes are perpendicular to the end of the block. Once the holes are drilled, then you can proceed to shape the heel. Once the heel is shaped it is extremely difficult to drill these holes. If you are using the mortise and tenon method, the tenon must also be prepared and drilled before the heel is shaped. If you are using the butt-joint method, there is a step you must perform before drilling the holes for the inserts. You must accurately cut an angle on the bottom of the heel in such a way so that when the neck is mounted to the body, it sits at the correct angle in relation to the top of the guitar. In effect, you are going to create the neck-set. Using an angle-finder, get the angle from the guitar's top to the sides where the neck will be joined. Set your tablesaw's blade to this angle and cut your heel block to the same angle making sure you have the fret (either 12th or 14th) where the neck joins the body marked carefully. Cut the angle to this fret position. When you drill for the inserts, you must drill the holes perpendicular to this bottom surface of the heel otherwise your neck's angle will be incorrect.
I also deviate from the book when I shape the heel of the neck. I use a belt sander. It's a large stationary belt/disc sander I got from Grizzly. They don't make the best stationary tools out there in my opinion but this sander is sufficient for my purposes. It's a heavy, stable unit that has given me little trouble in the months I've had it. The end rollers on this sander are 3 inches in diameter. This is a good diameter for the curve at the transition of the neck to the heel. I use the end roller to sand the curve into the blank. It works well for me. I plan to make a jig which would mount to the sander and allow the neck to be clamped down then pressed into the roller. I currently do this by hand. Once I make the jig, I'll post pictures of it here and explain how I made it.
If you plan to make a non-slotted headstock without a volute the technique in the book is straigtforward. In my case, since I own a thickness sander, I thickness the headstock blank to 1/2 inch using that tool. If you plan to have a volute on the back of your headstock, you must modify your technique. Rather than cutting the headstock down to 1/2 inch thickness before you glue it up to the neck, you simply glue it up at it's full thickness. Then, draw your volute's shape on the back of the headstock/neck. Mount the neck into a cross-slide vice (one with handwheels to move the table in the X and Y directions) which is securely bolted to your drill press table. Mount it so that the headstock is parallel to the table. Place a 1/2 inch end-cutting router or milling bit into the drill press. Using the drill press's fastest speed, you feed the headstock into the bit thus milling off the wood everywhere except where the volute is. Make shallow cuts. Don't try to reach final thickness in one pass. Make several passes, lowering the drill press's quill and locking it into position for each pass. Once you have the headstock thicknessed, you can then detail the volute using chisels, small rasps, sand paper, etc. This mentioning of this technique is presupposed by the fact that you do indeed own a drill press and a cross-slide vice. The vice can be purchased at Harbor Freight for about $40 or so. DO NOT attempt this technique without the vice. Feeding the headstock into the bit by hand only invites disaster. A Wagner Safe-T-Planer can also be used for the operation. Be careful not to encroach on the volute no matter which tool you use.
For slotted headstocks you have some extra work ahead of you. You must first apply the headstock overlay and shape the headstock to it's profile. If you plan on binding the headstock do it now. Then, using a doweling jig, you must drill the holes for the tuning keys. I suggest you purchase the tuners first so you can see exactly what the requirements for mounting are. Some steel-string slotted head tuners require a 3/8" or 10mm hole for the bushing on the tuner's plate, and a 1/4" hole where the peg enters the headstock on the inside of the slot. This requires two different drilling operations per hole before the doweling jig is moved to the next hole position. Most tuners of this type come with a set of bushings that are placed on the inside of the slot nearest the edge of the headstock. If you drill through to the depth of the inside of the slot using the 3/8" or 10mm bit, then you'll need to use a second set of these bushings on the hole where the peg enters the headstock on the inside of the slot. Either way, the holes must be drilled before the slots are cut. The book, while outlining the construction of a classical headstock, shows most of the same operations you'll perform in making a steel-string slotted headstock. I cut my slots on the drill press using a 1/2" forstner type bit. I then clean up the slots with a very sharp chisel. If you're going to square the tops of the slots (the forstner bit will leave them rounded), use a sharp chisel and make small cuts till you have it right. To create the ramps at the bottom of the slots, I take a 1/2" dowel and put it in my drill press. With the dowel spinning, I place sandpaper on it to remove some material - just enough so that when a piece of 100 grit sandpaper is wrapped around it, it's overall diameter is 1/2". I then use this in a lateral motion to create the ramps at the bottom of the slots. It works well, and takes only a few minutes per slot. When you mount the tuners be sure to drill tiny pilot holes for the screws otherwise the edges of the headstock will split. I love the way slotted headstocks look. I do not love making them. I have made two guitars with this type of headstock. I do not plan to make many more unless a customer just absolutely has to have one. Then, he will pay me dearly for the option.
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To be continued . . .