Building: Tools, Fixtures, Jigs & Templates

[alder]

I like to build oddball short scale basses. You can't buy them. You can't even buy parts for them. If you want one, you're going to have to start with lumber and work your way up. That can involve some fairly precision work, the kind that requires specialized tooling. I thought I'd post some of the creations from my garage workshop for others to see and perhaps copy or improve on.

Almost everything here can be made from parts and materials from your local hardware store, with a few exceptions noted.

Good sources:

http://mcmaster.com
http://rockler.com
Invalid Link Removed
Invalid Link Removed - for those Danelectro truss-head screws !

Home Depot, Lowes, your local hardware store, paint store, and lumberyard

and of course, eBay and Amazon.

And all you high school kids - take wood shop. You can make all of this stuff easily there. Man do I envy you for that. I wish I'd taken wood shop instead of French. Would have been a lot more useful.

 

[alder]

Here's my first entry ...

Radius Jig

The Radius Jig is capable of cutting constant radii from 6 to 16 inches, both concave and convex, as well as convex conical radii. That means it can cut sanding blocks, clamping cauls, and 'compound radius' fingerboards. Sanding blocks can be cut up to a finished length of 14", while fingerboards can be cut up to 28", enough for even an extra-long scale bass.

As far as I know, this is the only design that can cut both inside and outside radii. Of course, being made of wood, this is only suitable for very low production, home-workshop type use. In a factory setting, a piece like this would wear out very fast, but I expect it to last me as long as I need it.

My goal was to build a dual-purpose jig as solid and compact as possible, at minimum cost.

Front view of main frame, showing friction arm & setup supports inside.
The odd shape of the base was already that way, I just used it as-is.

Back view of main frame, showing adjusting slots & wing-nut attachments.
For this project, I standardized on 1/4-20 fasteners, and used a pile of them.
( In this shot, the Sanding Block Jig is installed on the other side. )​

The Radius Jig is made mostly from 3/4" plywood scrap, with 3/4" hard maple for bearing surfaces. Inside are side setup supports and a center support bar for setting up the Fingerboard Jig. The main part of the jig is a large box frame of plywood. The back of the frame has two sets of vertical 1/4" slots. There are also setup supports are either side, and a pivoting friction arm installed in the center.

The top of the Radius Jig is a slide for the router, made of hard maple. There is a 1" cutting slot down the center of the top for the bit. All of the other jigs attach to the slots on the back of the Radius Jig with 1/4-20 hanger bolts, fender washers, and wing nuts.

If the frame was 4 inches taller, it could cut 20" radii as well, but the plywood I had wasn't big enough, and I didn't want it to be too big and bulky. I doubt I would ever want to cut a 20" radius anyway, that's almost flat. At the other end, the 6" radius isn't very useful either, but it didn't add anything to the design except extending the slots a bit, so what the heck.

The Radius Jig is used in conjunction with either the Fingerboard Jig or the Sanding Block Jig:

Fingerboard Jig

For fingerboards, the Fingerboard Jig is installed into the Radius Jig. The main part of the Fingerboard Jig is a piece of 3/4" plywood with a pair of 1/4" vertical slots. At the top of the Fingerboard Jig is a 2-1/2" wide maple shelf to which the workpiece is attached with double-sided tape. The geometry of the shelf is such that the workpiece is centered and squared below the cutting slot, and centered above the pivot line. A slot and clamp on the front of the Fingerboard Jig receives the support arm.

Pivoting fretboard jig assembled in main frame for conical / compound cut,
with first test piece. More wing nuts.​

The maple shelf of the Fingerboard Jig is not glued to the plywood under-shelf, it is held on with screws so that it can be adjusted with shims, or even replaced if necessary. Using folded paper as shim stock, the maple shelf is adjusted to have less than 0.2 mm vertical runout from side to side at any point along the entire length. Also, the runout from end to end is no more than 0.25 mm.

A pair of sliding braces mates with the slots on both the main jig and the Fingerboard Jig. A 3/8" steel rod serves as the pivot, with special angle bearings and lock collars to keep everything in line. The only part that is not readily available at your local hardware store is the bearings and collars, which can be found at McMaster-Carr ( mcmaster.com ). The short inner set of slots are not used.

Detail of fretboard jig pivot, adjustable brackets, showing pivot rod, and indicator
​

Note that if you discard the compound radius feature, you can dispense with the rod and bearings, or at least the bearings, and just use simple straight pivots, similar to the sanding block jig below. Eliminating those parts means you can source the entire assembly from the hardware store, and save some money too. I would retain the rod for strength and ease of adjustment.

To adjust the radius, first the jig is centered and blocked up on the side supports, and held in place by tightening the clamp around the tension bar. I find popsicle sticks make good blocks. The braces are loosened front and back, and will then slide freely up and down. A small screw inside the slot is aligned with marks on the Fingerboard Jig, and then everything is tightened and the blocks are removed. Radius settings are infinitely adjustable, and different settings can be used on each side to achieve compound radius cuts.

The friction arm clamp is then loosened, allowing the jig to swing. In practice, keep the clamp tight enough to hold the jig in place, but still allow adjustments.

For actual cutting, I use a 3/4" bowl-cutting bit, with rounded corners. This bit leaves less tool marks than a regular square-ended bit. First, center the bit above the workpiece, and lower it to just above the center. Lock in this depth on the router. Pull the router to the end of the slide, and make a full cut down one edge of the piece. Move the Fingerboard Jig 1/8"-1/4", and make another cut. Repeat until you reach the other edge of the workpiece. This should leave a strip in the center uncut.

I find moving the jig incrementally and making full side to side cuts with the router gives better results than moving the router incrementally and jiggling the workpiece under it. By making very small movements of the workpiece and a lot of passes with the router, you can minimize the flats and crowns that will naturally result from this method of cutting.

Finally, sanding with a radius block will remove any tool marks and imperfections, and round over the uncut flat in the center.

Sanding Block Jig

To make radius sanding blocks, The Sanding Block Jig is installed into the Radius Jig. The Sanding Block Jig consists of two parts: a router slide that is a shortened version of the Radius Jig slide and mounts to the back of the Radius Jig, and a swing arm that mates with the Radius Jig in the same manner as the Fingerboard Jig.

Sanding block jig assembled in main frame. The tight fit of all the components is apparent.
The cutting is now done on the inside of the swing arm, whereas above it is done on the outside, thus producing the opposite curvature.​

To set up the Sanding Block Jig, first the friction arm is locked up out of the way. Then the swing arm is placed on a block and the pivot braces loosely attached to the back of the Radius Jig. I use a 3/4" piece of pine for a block. The radius is selected by moving the pivot braces between the pre-drilled holes in the swing arm, then the pivot braces are secured tight to the Radius Jig.

The pins for the braces are 5/16" bolts with wing nuts, and the braces are double sided for greatest strength and stiffness. Note that you can't use a continuous rod for the pivot here as above, unless you want to drill a hole through your router, which would probably void the warranty.

The workpiece is installed to the pivot arm with double-sided tape. The workpiece is assumed to be 3/4" x 3.5" dimensional maple, easily available at any hardware store. The maximum length is 10-11". Another 3/4" block is then placed on top of the workpiece, and the router slide is then installed snugly on top of it. Both blocks are then removed.

Cutting a sanding block is the inverse of cutting a fingerboard in almost every way. I find a 1/2" straight bit works best. To set the depth, center one edge of the workpiece below the bit, and lower it until it is not quite touching, about 1/16". Lock in this depth for the first rough cut. For sanding blocks, the best way to cut is to start with the router at one end of the block, and swing the block under it, moving the router 1/8-1/4" on every swing.

For all but the smallest radii, you can swing the workpiece out into the clear where you can inspect it. When the rough cut is done, lower the router but just enough to touch the workpiece, and make another full pass over it to clean up the tool marks. This should leave a surface that is smooth and even to the touch, with just a slight swirl pattern. This is good enough for a tool, after all, sandpaper is not smooth either.

It is well to note that cutting a piece of wood to an exact radius is not all that critical, and would actually be very difficult. I doubt even factory made-boards are better than +/- 1/4". I think mine are at least that good, but it really makes no difference if it is a little off. What matters is that the board is consistent from edge to edge and end to end, with no bulges or dips anywhere. For the sanding blocks, you would also have to account for the thickness of the sandpaper, which i did not even bother with. Besides, once you install the frets, that will change the radius again. Happily, the effect of the sandpaper and the frets are opposite, and tend to cancel each other out.

Radius Sanding Blocks & Clamping Cauls

To finish the block, I glue a matching piece of pine scrap to the back, cut to length, sand all the sides smooth, and round-over the top edges. Finally, label it on all sides. I find my wider, longer sanding blocks work much better than StewMac's. Of course, you could also make shorter ones, or narrower ones, whatever you like.

Assortment of sanding blocks​

Clamping cauls are similar to sanding blocks, but only 2.5" wide, and single thickness, cut from soft pine scrap in lengths enough to cover an entire fretboard. I had a pile of scrap wood leftover from building furniture when I started all these projects, and it is almost all gone now. Have to go to the scrap store.

Sorry, blocks are not for sale. The jig is not made for mass production, and it takes a lot more time than you'd think to set up, cut, and finish one of these. Stewmac's outrageous prices for their sanding blocks are not so outrageous actually, although I prefer my own blocks to theirs. Add to the time, the materials and the shipping, and it is just not worth it to me - I have thought about it.

Right now, the jig is set up to cut 12 inch fingerboards, and that is how it is going to stay. I can easily re-radius a 12 into a 10 or a 14 by sanding. 16 is so flat that you can skip the routing part and just sand it, and 7.25 is a relic. Compound fingerboards are not necessary for a bass, the action is much higher than a guitar and there is a lot less string bending.

 

[alder]

Fret Slotting Jig

The Fret Slotting Jig is basically a very precise mitre box. What makes it a fret slotting tool is the Fret Guide, which attaches underneath the workpiece with double-sided tape, and engages a pin on the Fret Slotting Jig directly below the saw blade. The holes in the guide are spaced to Fender's formula, so depending on which hole you start with for the nut slot, you can cut anything from a 36" bass to a 20" ukelele, and all the standard scales in between. The guide fits snugly between the inner rails of the jig to keep the workpiece centered and straight.

The scale guide and angles are aluminum from Home Depot. I just happened to have the angle material lying around, and it worked out really well, but there are a lot of other ways you could build this mechanism.

This design is inspired by StewMac's fret slotting jig.​

The left jaw of the saw guide is fixed to maintain a perpendicular angle and align the blade with the pin. The right jaw is adjustable to set the tensioning on the saw. Each jaw holds a waxed maple block which together serve as the saw guide and depth stop. The height of the depth stop is set using the bolts on the top, and then locked in with the wing nuts on the side.

The saw is an $8 hobby saw with a 0.022" kerf, almost identical to StewMac's 0.023". It is important to use a new sharp saw, as a worn saw will bind badly in hard maple or rosewood and make the job almost impossible. The jig can also be used freehand to cut the back side of the nut slot for a Fender nut, and then hog out the material for the rest of the slot.

This test piece came out so nice that I kept it to use some day.
As a test article, it came out too thin, so I glued a thin piece of walnut to the back,
which will make a unique stripe in the final assembly.
​

Actually, there is an easier way to make a short-scale bass fingerboard. Head on over to StewMac, and pick up one of their long-scale 'boards. Convert the first fret to a nut slot and install the dot markers accordingly -> 32". The same operation at the 2nd fret -> 30.3", 3rd fret -> 28.5", etc. All of Fender's scale lengths are related like this, you can cut a bass right down to a guitar (5th fret), the only problem is you run out of frets at the other end. That is why my scale guide above will make anything from a bass to a ukelele, depending on which hole you start at.

So why then all this clap-trap? Being able to make a board entirely from scratch opens up a world of materials, from incredibly cheap but nice maple, to dozens of kinds of tropical hardwoods that can be purchased online.

I get very nice 1/4" x 2.5" hard maple pieces at my local Lowes store. Search through the pile, and you can often find nicely figured pieces, from flames to birdseye, for just a couple of bucks. Pieces of tropical hardwood suitable for guitar fretboards are available from online woodworking suppliers at very reasonable prices as well. Try rockler.com.

Bubinga is often very reasonably priced, is hard with a grain structure similar to 'rosewood', and has a nice orange-brown color. You'll find it on many Rickenbackers. Purpleheart really is purple. One of these days I'm going to try a piece of walnut from the hobby store around the block. Wisdom is that walnut is too soft to hold frets, but I bet it works fine.

The longest board I've made yet is a 24 fret 30.3" for a Bass VI, which fit neatly into a 24" blank, and would be impossible to cut down from a StewMac board. Most boards leave several inches of scrap leftover, which I save to cut dots from.

The dot markers in the example piece above are actually cut from scrap rosewood with a 1/4" plug cutter in the drill press. For rosewood boards, I have used maple dots. Gives a nice woody look to the neck. You can also cut dots from any solid color pickguard material, so save those scraps! Rumor has it that Fender's famous 'clay' dots were nothing more than plugs cut from old floor tiles. Pearl and abalone dots are best purchased pre-made. Someday I will also have to teach myself inlaying, and go beyond plain dots.

Here's a shot of my drill press table and fence, homemade from scrap, of course.
Aluminum T-tracks are available from Rockler, good for all sorts of things.
​

Final Note:
There is no need to buy "luthier grade" wood, whatever that really is. If you did, you got ripped off. Quartersawing is an expensive gimmick. Find me a quartersawn Fender neck - they don't bother with it either.

​

 

[alder]

Truss Rod Channel Jig

The Truss Rod Jig clamps and centers a workpiece in place while the router slides on rails above it, making for a very straight and precise cut. The workpiece can also be mounted off-center or on an angle for alternative cuts. The side rails overhand the base plate to allow routing of necks with angled headstocks.

An accessory drill guide attaches to one end allows for drilling into the end of the workpiece. So I finally found a use for that thing.

Showing the removable centering block and end-drilling attachment​

 

[hdracer]

Very nice.

Wanna sell some radius blocks?

 

[alder]

Reverse Routing Jig

The Reverse Routing Jig holds a router above the workpiece, which is secured to a flat smooth surface below. I use an old piece of countertop, not a carpet, as in the picture. By sliding the router over the workpiece, you can mill the face of the piece. Height is adjustable by changing the legs. This jig is very useful for milling Fender-style headstocks. It is also possible to cut angled headstocks by blocking-up the workpiece and using the longer legs. This jig is basically an upside-down router table, with one great advantage - you can see what you are doing.

The plate is an old piece of phenolic I had lying around - very stiff stuff.
The 'legs' are pine scrap, in whatever width works.​

Edge Binding Jig

The Edge Binding Jig is inspired by StewMac's attachment for the Dremel, except that mine uses a real router, and is designed to fit into tight spaces like the inside of Fender horns, which StewMac's does not do well. The edge follower is a nylon cap nut on a 1/4-20 bolt threaded tightly through a block of maple. The jig is also useful with the follower removed for routing neck pockets, round-overs, etc. The length of the base plate, with the maple stiffeners, allows a large area of contact with the workpiece for stability, something that can be a real problem with a standard router base. The small DeWalt 611 router is easily controlled with one hand, while the other hand keeps the jig aligned on the workpiece. I sometimes even clamp the whole thing upside-down and use it as a quickie little router table.

​

The long narrow piece of polycarbonate was positively floppy compared to the phenolic above. The maple stiffeners were an absolute necessity. Maple is great for this sort of low-volume tooling, as you can work it with wood tools but treat it like metal. But it won't wear like metal.

 

[alder]

Various Templates

The control cavity templates were reverse-engineered from a Gibson-style guitar. They are cut from 1/4" polycarbonate, while the matching cover template is MDF. Again, inspired by StewMac's design. StewMac does not include the cover template, they expect you to buy their cover.

For drilling tuner holes ... hard maple scrap from neck builds
​

The real reason for making these simple templates is that if you screw up one of these, you just ruined a piece of scrap, no big deal. You didn't ruin a real neck. But once you get one of these right, you can use it to assure that you don't ruin a real neck.

Custom Necks ...
​

Here in the Northeast USA, Home Depot, Lowes, and others sell 3/4" hard maple that is entirely suitable for guitar and bass necks. Pick through the pile and select the best piece. I have found nice flames and birdseyes at times - you never know. Home Depot will even cut you a custom length. Cap that with a 1/4" thick fingerboard to make a Fender-style bolt-on straight neck, or see below for angled headstock.

​

I also have an assortment of body, pickup, pickguard, and neck pocket templates from various sources. StewMac's neck pocket template is highly recommended; their pickup templates are also very good except for the precision bass, which is completely wrong.

One way to make a body template:

Find a good hi-quality image of your favorite guitar on the interwebs. The image has to be straight-on, not angled in any way. Project it onto a piece of mdf or tracing paper, again, straight-on. Move the projector in or out until the projected scale length is correct, and trace the outline. You will have both the shape and the size right. Don't forget to trace pickguards & other details.

Another thing I've done is to suspend a small flashlight from the ceiling, and drop a plumb line from it. Place the piece you want to duplicate on a piece of paper or other material directly below the light, and trace the shadow. This can save having to do a lot of dis-assembly on a headstock, for example.

For solid body blanks, poplar is often available in suitable sizes at very reasonable prices from your local lumberyard. Poplar is a nice, close-grained, not too heavy wood that is easy to work and requires little or no filling. Best for painting, it can be stained successfully as well if you semi-seal it first with several coats of 'natural' or clear stain before applying color. Unplugged, it has a very lively bright tone, although that matters little on an electric.

 

[alder]

Padded Sanding Blocks

Sanding blocks are 1/8" neoprene foam (mousepad) glued over 1x2 & 1x3 scrap pine, with 1/4" roundovers ( makes 3/8" roundover with padding. ) Use waterproof contact cement. Large block is sized for 1/4 of a standard sheet of sandpaper, will also take half of a 1/3 sheet piece. Small block works well for details, inside horns, etc. The neoprene grips the sandpaper exceedingly well, wet or dry, and has just the right amount of 'give' for very fine sanding.

Such a simple idea, yet it makes a world of difference in finishing.
StewMac - feel free to copy this design, I've copied enough of yours !​

 

[alder]

Neck Scarf Joint Jig

The scarf joint jig clamps to a mitre saw to hold a workpiece square and perpendicular with double-sided tape. The saw is simply set to the desired angle, and each side of the joint is accurately and easily cut. For glue-up, use matching shims to prevent creep under clamping.

more to come ...

 

[alder]

Build Your Own Truss Rod

The best truss rod for a guitar is one, or better yet two, steel bars glued tightly into the wood. A neck like this will never warp or need adjusting. Just look at any Martin or Danelectro from 50 years ago - they are as straight and true as the day they were made. How many Gibsons can you say that for?

All a guitar neck really needs to be is straight, dead straight. A truss rod should never be used to adjust action, action adjustments are at the bridge, or by shimming the neck. Of course, on a non-bolt-on neck, there is no way to adjust a bad neck set, so they put a truss rod in as a kludge, but it doesn't really work for that. That is where 'dead spots' come from, as the truss rod subtly twists the neck out of shape.

The 1/2" x 1/8" mild steel bars available at any hardware store work fine as truss rods. Degrease them well, and scratch them up good with coarse sandpaper. Route a tight slot, and put some wood glue in, then push the bar in so the glue overflows and fills the entire space. Then glue on the fingerboard. When the glue dries, it will grab the scratches and hold the bar like iron, no pun intended. No need for bothersome epoxy. Since the steel is completely encapsulated away from the oxygen in the air, it won't rust either.

I use 2 bars in angled channels that form sort of an A-frame from the heel to the nut, like a Danelectro. Channels like this are easy to cut on my jig described above by mounting the workpiece suitably offset and crooked. I've also used 1/2" square steel tube down the center like an old Martin, but this is rather more bulky and heavy.

Oh, and btw, steel is much stronger than graphite. Graphite is only stronger than steel on a weight basis, which is irrelevant here - we're not building airplanes. ( I used to ... ) On a volume basis, nothing beats steel, unless you have some titanium handy. And there is definitely limited volume inside a guitar neck. Aluminum is crap best suited for beer cans. Steel is also cheap and easy to work with.

Some manufacturers use carbon fiber rods alongside an adjustable truss rod. It's almost like they know it's wrong, but they can't bring themselves to admit it.

Trust me: guitar = steel bar, it will play great forever. Unfortunately, the same is not true for a bass.

I have come up with literally dozens of ideas for adjustable truss rods for bass, and here is the best one:

This truss rod is also almost entirely from Home Depot parts. You'll need a 3/16" plain mild steel rod, one 2" 10-32 bolt with the head cut off, two 10-32 coupling nuts, one 10-32 hex nut, and of course the spoke nut from StewMac. If you don't like the spoke nut, there are lots of other options, you could even make your own nut. You'll also need a thread cutter, propane torch, and hi-temp silver solder and flux, available on eBay, a bench grinder, and a solid vise.

In theory, this solder requires a specialized torch and gas, but these parts are so small that you can get away with an ordinary plumbing torch, it just takes longer to heat them up. You'll know the parts are ready for solder when they glow orange. You should grind mating surfaces slightly before brazing to get the zinc coating off and make a rough surface that will grab well, but where that is not possible, like on threads, the heating process will burn the zinc off. There are lots of instructional videos on brazing on YouTube, watch a few and teach yourself, it's not that hard, much like ordinary pipe sweating. Practice on some scrap bits. A properly made braze joint is as strong or stronger than a weld.

On to the actual assembly:

Cut the head off the bolt and insert it into the spoke nut, securing it with a touch of solder to the threads. The solder will find its own way up the threads, it just takes a touch. Drill out the first coupling nut so the bolt slides through snugly without binding, then grind one side down a bit. Assemble it as in the pictures, thread the hex nut on snugly, and carefully secure it with just a touch of solder, making sure that you don't overdo it and solder the entire assembly solid. At this point, you may think you've done that, but it is probably just the flux sticking, and you can break it loose with a wrench. Finally, grind the hex nut down to a round nub so that it will rotate freely when you make the final assembly.

Mark the center of the rod and torch it until the metal glows, then bend it back on itself. This might take more than one pass and some hammering to get it really tight and straight. Did I mention, you're now a blacksmith? Determine the length you need, and cut the ends to fit the assembly you made above. Thread the shorter end no more than 1/4". Turn the other coupling nut about 1/8" onto the threads you cut and secure it with a touch of solder, and grind it down all around. Grind a slight flat onto the inside of the long end, and while you're at it, grind any bulge off the bend you made.

Thread the end of the bolt about halfway into the fixed coupling nut. You want to be able to drive it in or out to loosen or tighten the rod. Align the other coupling nut onto the flat you made, clamp it lightly ( I use a small vise-grip ) and solder it on both sides. Be generous with the solder, but don't get any on the rotating parts. Finally, grind the whole thing down as sleek and skinny as you can. Lubricate the rotating parts with a few drops of 3-in-1 oil, which will find its way inside, and you're done. You can wrap the shafts individually in thin tape to prevent rattling, which they don't anyway, and decorate with adhesive flowers and glitter if you want.

The only tricky joint on the design is the last one, you'll want to align everything very carefully before you commit to it. On the plus side, if it doesn't come out right, you can torch it apart and clean everything up on the grinder and start over. You just waste some solder.

Have a container of water handy to quench the parts after each torch or grinding operation. Make sure you are comfortable handling the torch, and take all safety precautions. This is really not as hard as it sounds. I got started brazing when I had a complicated plumbing job in the house, and after I described it to the plumber, he wouldn't even return my calls. So I taught myself on some spare parts and did the whole job myself, and needless to say, the plumber is fired, and I do all my own work now. To this day, it has not leaked a drop, and I still marvel at how I folded everything into such a small space. The only difference here is the hi-temp silver solder, which is much stronger than plumbing solder, although it is possible that plumbing solder would be strong enough, I just never tried it.

The beauty of this truss rod design is that it is simple to install, and removable. The protruding spoke nut is the thing that forces it to be removable, so that you can do the finishing woodwork on the neck without having to work around it. A standard nut would not have that problem. Also, you have to dremel out a notch in the body for the spoke nut, which is easy enough. Alternatively, you could make a notch in the neck and recess the nut into it. This neck clearly has room enough at the end to do that.

The channel for this rod is a simple 1/4" straight route. Make it a bit longer than the rod itself, and a bit more than 3/8" deep. I use a round-end straight bit, you can find them online. The heel end is then widened and deepened a bit with a 3/8" round-end straight bit. This is as small a channel as is possible for a double-acting truss rod. Make sure the rod runs in and out freely before gluing on the fingerboard. Before the glue dries, run the rod in and out to sweep away any glue drips; do this until it comes out clean. Then wipe off the rod and set it aside, it doesn't have to go back in until the neck is finished.

Why a spoke nut though? Seems like extra bother. I like the spoke nut because it installs easily at the heel, you just route the channel right through to the outside. And the spoke nut is easily adjustable without disturbing the neck or even the pickguard. Just stick anything that fits into it, and give it a turn. An allen wrench works, but my favorite thing is the wrong end of a drill bit. I even like the way it looks.

Drilling for a headstock adjustment is no simple matter, you could easily ruin your project and have to start over. Also, a headstock adjustment places the bulkiest part of the rod in the thinnest part of the neck. Small wonder Gibson headstocks break off so easily. There is plenty of room in the heel for any kind of mechanism you want.

The spoke nut was pioneered on Musicman instruments, but on those installations it is only a single acting rod. In fact, Musicman uses the awful 'skunk stripe' design, the worst truss rod design of all time. StewMac sells a version of their nice double-acting truss rod with a spoke nut, but I think my design is better.

But wait, there's got to be something wrong with a removable truss rod !!! There just has to be !!! It's just not done, not by proper 'luthiers' !!!

I ask you: why not? Once you sock it all the way home, this rod will not fall out even when slack, in fact you can't pull it out with bare hands. It doesn't rattle once you put a little tension on it, at which point you can't pull it no matter how you try. And it it ever breaks ... but I don't think my design ever will break. Most truss rods are not removable because they are lousy designs. Removable is really how all truss rods should be made.

Actually, the rods in my Ric 4001 are removable if you slack them, although I don't think that was one of the design criteria. And good thing too, they have a reputation for breaking, knock on wood.

This rod goes almost all the way up to the string nut, and still has about 1/4" of wood above and below it. That's more than enough, don't underestimate the strength of maple. If you wanted to make a really really fine neck, you could stop the rod under the second or third fret where it is thicker, I've seen necks built like that and it doesn't seem to do any harm. I don't mind a slightly chunky neck, and like to have the support go all the way.

Remember, the amount of lateral force that the truss rod has to exert on the neck to counteract the bending moment of the strings is tiny. All this steel is total overkill, but there is no way to make it any smaller, it wouldn't be stiff enough to function properly.

For a much faster and easier route to a custom length truss rod, buy a standard-length cheap double-acting rod from China on eBay, cut to length, and braze the two ends back together. I've done it that way too. The rod in the pictures is actually made from parts I reclaimed from a prototype that I torched apart, so it looks kind of messy, and is a bit different from the written description, but it is perfectly sound. This is the third truss rod design I have built, and it will be the last, I don't think I will come up with a better one.

This design could also easily be simplified to a single-acting rod. Omit the entire adjusting assembly, and thread the longer end of the rod for about an inch. Drill out a coupling nut and slide it over the threads and braze it to the other shaft, then thread the spoke nut on and you're done. What makes a rod double-acting is that the adjuster can push or pull, because it is 'captured' on both sides. This modification can clearly only pull. I have never seen a long-scale bass that needed a double-acting truss rod, they all pull forward on their own, and only need to be pulled back. I have seen short-scale basses that needed a double-acting rod and only had a horrible single-acting 'skunk stripe' rod. There is nothing you can do for that but scrap it, so I would always put a double-acting truss rod in a short-scale bass, just in case.

 

[walterw]

Very nice.

Wanna sell some radius blocks?

+1, awesome!

actually, what you wanna make to sell is some reverse radius blocks, convex instead of concave, for shaping the bottoms of nuts and such. nobody sells those.

 

[Turnaround]

Build Your Own Truss Rod
All a guitar neck really needs to be is straight, dead straight.

Not really.The correct amount of relief is the ideal neck setup. And that will depend on a number of factors including the player's technique. And a fixed truss rod cannot compensate for expansion and contraction of the wood from changes in moisture content resulting from changes in relative humidity. Martin used to use fixed truss rods, but gave that up in favour of adjustable ones. There's a reason and it's not based on $$ - an adjustable truss is a more expensive option to manufacture and install.

 

[walterw]

Not really.

i hate to come here and quibble on what is shaping up to be a pretty cool build thread, but i'm inclined to agree. you can likely get to "petty good" with a fixed neck and some specific string set, but if you want perfect, like .006" relief, regardless of whether you have 50-110 flatwounds at standard tuning or 40-95 rounds tuned a whole-step down, regardless of climate, i think you need adjustability.

(and all too many old dano and martin necks might be evidence for the prosecution, not the defense )

 

[alder]

Not really.The correct amount of relief is the ideal neck setup. And that will depend on a number of factors including the player's technique. And a fixed truss rod cannot compensate for expansion and contraction of the wood from changes in moisture content resulting from changes in relative humidity. Martin used to use fixed truss rods, but gave that up in favour of adjustable ones. There's a reason and it's not based on $$ - an adjustable truss is a more expensive option to manufacture and install.

You have to adjust it because you can adjust it, because you have to adjust it, because you can adjust it, because you have to adjust it ... ad infinitum.

I've set up a lot of six-strings, and after a while I noticed that the best setup always amounted to so close to dead straight that you might as well just go there and be done with it. Which is the last thing an adjustable truss rod wants to do, is be straight. And once you get to that perfect place, why would you ever want to leave?

With a sufficient amount of steel firmly bonded to the wood, temperature, humidity, and everything else are going to have NO EFFECT. The wood can strain all it wants against the steel, the steel is not going to budge. There is the factor of thermal expansion of the metal, but that would happen with an adjustable rod too, and it is pretty inconsequential with steel. ( Not so for aluminum, a fixed aluminum rod would have some noticeable temperature issues. Wood vs aluminum in a wrestling match, I wouldn't try to pick the winner. Kramer found that out with their aluminum necks. )

Martin gave up on it for marketing reasons, not engineering. For itty-bitty guitar strings vibrating in tiny arcs at high frequencies, there is enough relief just from the bridge height. Now a bass is a different story. Bass strings vibrate in big arcs, and you can get a much lower action with a curved neck than a straight one. But you can't really predict what curve will work best, and it will also depend on the strings, you simply cannot build in a fixed curve. So ... you are cursed with an adjustable truss rod. On a bass. That's what I said, but People don't seem to read the whole thing before firing off replies.

Over and over, modern 'luthiery' seems to be exempt from the laws of nature, physics, and engineering, not to mention common sense. There is so much bullsh!t in the business, all designed by the marketing departments to drive sales and prices. Classical luthiery is about acoustic instruments, where woods, finishes, and construction can have a huge impact ( or not. )

But with electrically amplified instruments, you can take 99% of that 500 years of tradition and throw it in the trash, it is completely irrelevant. Fender did just that when he made the first Telecaster. First person ever to build a guitar out of firewood. He was a genius. So was Nathan Daniel ( Danelectro. ) Wonderful guitars made out of cardboard, more or less. The corporate entity that is and always was Gibson has used all that irrelevant tradition merely to justify their outrageous prices, and a lot of others do the same. Marketing, pure marketing. Les Paul built his first electric guitar out of a fence post, and it worked.

The other reason adjustable rods are used is to compensate for bad neck sets. That amounts to correcting the action with the truss rod. You can get away with a little of that, but trying to fix a bad set with the truss rod is going to bend dead spots into the neck that cannot be fixed except by grinding the hell out of the frets. That is why some guitars are dogs. Doing this cuts down the manufacturer's reject rate significantly. Most people don't know a good instrument from a bad one anyway, and they can always pawn off a dog on someone. I have an Epi EB-3 that no amount of adjusting will ever make play right. I finally gave up and put flatwounds on it. The neck still wants to buzz, but the strings won't do it. Ha ha - creative solutions. ( A simple shim would fix perfectly, but alas, that is not possible. )

I own a number of 50 year old guitars with fixed steel rods, and they play great. I've also built a few that way, and they play great. I didn't spend most of my life on the edge of my bed learning guitar solos, I went out and got an engineering degree, and became a rocket scientist. No kidding, I still get a kick out of saying that. Until the bottom fell out of rocket science, damn Russians suddenly getting all friendly on us back in the '90s. Rocket science just isn't what it used to be. Anyway, the result is that I may not be a great player, but I know how to design and build things, and electric guitars are not much more complicated than furniture, marketing bullsh!t aside.

I do love to pick on Gibson for their outrageous prices, bad designs, 'aesthetics', hopeless ergonomics, poor workmanship, and random quality control, but the truth is that the entire industry depends on all the marketing nonsense to sell stuff, and they're all just as guilty. Your typical cheap Chinese guitar can be made to play and sound great at a fraction of the price of a 'real' one, if you know how. Any guitar that isn't outright defective can be set up to play well enough. That must scare the crap out of the big names. Great guitars come from factories. Expensive guitars come from marketing departments.

This rant is too long. The fact is, if you built a guitar with a fixed truss rod today, no one would buy it, because it doesn't have an adjustable rod like it is supposed to. Marketing victory. Drink the Kool-Aid. Spend money. Sure, that Les Paul custom is worth more than a new car. Oh for God's sake, it's just a piece of wood !!!

 

[Turnaround]

With a sufficient amount of steel firmly bonded to the wood, temperature, humidity, and everything else are going to have NO EFFECT. The wood can strain all it wants against the steel, the steel is not going to budge.

No effect on the steel. But the wood will continue to react to humidity changes and when it's prevented from normal expansion and contraction it does things like splitting. This isn't rocket science, it's wood science.

Yes you can use a fixed truss rod. But there really is no advantage, whereas there is an advantage to an adjustable one. It allows for adjustments to compensate for the wood's behaviour and the player's requirements.

 

[alder]

No effect on the steel. But the wood will continue to react to humidity changes and when it's prevented from reacting it does things like splitting. This isn't rocket science, it's wood science.

In theory, yes. In practice, I myself have never seen it happen. Wood does not elongate to any significant degree with humidity, it swells laterally. If you are building a table out of oak, you'd better take that into account, but in this application it makes no real difference. And I believe most if not all woods have a pretty similar coefficient of thermal expansion as steel, that is to say, negligible for these purposes, so that is not an issue either.

As prosaic as it may be, wood is still part of mechanical engineering. Again, most of these concerns are due to luthiery being exempt from the laws of physics, and even the laws of carpentry. The amount of BS in the guitar business is truly staggering. You are aware that red guitars are twangier than blue ones, right?

The main reason you need a truss rod of any kind is that wood 'creeps' under load. Creep is not the same as bending, bending springs back, creep is permanent. Even the tiny bending stress caused by the strings is going to deform an all-wood neck over time, unless you get real lucky and happen to have used a piece of wood that is just naturally resistant, or make the neck so thick and strong that it just doesn't matter. Many materials 'creep', like plastics, and even glass, but metals do not. They bend under load, but even then, far less than wood, and in this application, you can assume that there is no bending at all. Or, to put it differently, you use enough steel to assure that it does not bend to any significant degree. I am unable to noticeably bend a 1/2" x 1/8" steel rod along the longer dimension in my hands, and that is far greater force than it will ever see in a guitar, and I use two of them. So, for all intents and purposes - no bending.

With an adjustable truss rod, you are basically building a defectively weak neck, and then cranking it back into shape ( hopefully ) with the rod, in the process placing additional stresses on the neck that can lead to long term failure. The truss rod also induces the wrong shape of bending, and introduces dead spots. A neck that has been severely corrected with the truss rod will never be a good one.

That is why 50-year-old Gibson necks pretzel-up, and 50 year old Danelectro necks don't, in fact, can't. A properly designed fixed rod will prevent all that failure from ever even getting started. If Leo Fender had stuck a steel bar up the middle of the Telecaster back in 1953, the adjustable truss rod would be extinct by now. Alas, instead he copied Gibson. No one is perfect.

Remember, I am talking about a guitar, not a bass. I guess I just have to keep saying that in bold letters. While a fixed rod would still be structurally superior on a bass as well, the result could never be set up very finely. And I do fuss over my bass setups, which are much trickier than guitars, basses are such buzzy beasts. Guitars are easy by comparison.

Finally, the traditional primitive single rod in a curved channel truss rod as found on many Fenders, Gibsons, and Rics, might as well be glued in, especially when it is under tension, so how is that really different? I tore apart a neck like that once, and had to pry the rod out of the slot. Have you ever adjusted a Ric 4001? If you think about it, all the special steps you have to go through are specifically to keep the rods from binding in the wood. yet, if you slack the same rod, you can pull it out. Friction can grip as hard as glue.

One problem with gluing in a steel bar is that the wetness of the glue will swell the wood, and the entire neck can go out of shape, and stay that way once the glue dries. You need to clamp it laterally to prevent this, but it doesn't take a huge amount of force. You want to glue the bars into the blank while it is still just a blank, and then do the rest of the work around them.

I need to take some more pictures, my latest adjustable truss rod design is really slick - cheap and easy to build from hardware store parts, double acting, spoke nut, simple straight channel, and removable. For bass.

 

[alder]

(and all too many old dano and martin necks might be evidence for the prosecution, not the defense )

Danelectro necks go bad through abuse and neglect. Store anything in a wet basement and see what happens. These were after all cheap guitars that no one took particular care of. Here's an example:

I bought a box of parts, the body had been stripped bare, and not kindly. In fact, I think they rubbed it on the sidewalk, and the neck too. The pickup tubes were all split, the electronics could play a techno track just from turning the knobs. But the worst thing was that the fretboard had separated from the back of the neck under the first three frets. Those old glues are not very waterproof.

The result was that the poplar back of the neck had to carry the entire load with no assistance from the fingerboard ( and rosewood is very strong stuff and an essential structural part of the neck. ) Poplar is not particularly strong at all, about equal to good pine, and what happened was the neck warped and the truss rods started to push out the back. This neck is extremely fine, and was probably over-sanded at the factory, then the stripper finished it. My point is, the steel bars weren't going to bend for nobody, and the wood actually started to fail around them, due to the separated fretboard. To make matters worse, at some point someone had filled the gap with glue, but not clamped it, in effect wedging the two pieces apart even more.

The repair was interesting. I steamed the fretboard off the neck with an iron and a wet rag and a splackling scraper that I put a temporary knife edge on. You probably couldn't do that to a modern adhesive, but the old hide glues come apart pretty easy. The biggest concern is not burning the dot markers.

The neck straightened out pretty well all by itself at that point. I clamped it straight, and crazy glued the rods in place, then reapplied the fretboard, making sure that everything stayed perfectly straight. The neck came out like new, but I still wasn't satisfied, and pumped more glue in through some tiny holes I drilled in the back, then filled with bits of toothpick.

Long story short ... sanding sanding sanding, poly clear coat everything, fret stuff, re-tube the pups, lots of tuner wash, etc etc , and ... a real nice guitar. Plays like the day it left the factory. Ok, you're probably not impressed with that, but it plays great, as good as many supposedly better guitars I have. Rings like a bell. The grain on this particular guitar is exceptional. You just can't get old-growth masonite like this any more. It came out a beautiful and very unique piece. At least, I think so.

One thing is that I do not press my luck with the neck repair, as I think too much wood has been removed to really be stable. So I do not keep the strings tensioned up unless I am actually playing it. Still, for an instrument to have even survived the amount of abuse that this one has seen, and still be restoreable to good playing condition, is a testament to sound design. Solid steel truss rods forever !!!

So if you have an old Danelectro with a bad neck, remember, it was probably run over by a car. Or stored in a lake. Or used to prop a sagging porch. Use a Les Paul to fend off a bear and see how it holds up. Kum bay ya, my Lord, kum bay ya ...

 

[alder]

Now that could be a whole new thread. What instrument would you choose to fend off a bear? I'm not talking about playing it, as any radio playing today's music should drive off all wildlife within earshot immediately. I mean swinging. I'd have to go with a Jazz Bass. Exceptional weight & balance, good reach too. Although the solid maple construction of a Ric would serve it well as well. I would not want a Gibson, as the headstock would break off with the first swat, and then it would be more dangerous to you than the bear. Or maybe a double neck. Or a piano, provided I had a block and tackle and time to rig a suitable boobytrap. Perhaps a well-played bagpipe ...

 

[Hopkins]

I tend to disagree with the theory that truss rods are used to compensate for a bad neck angle. You can adjust a truss rod to make the action look likes its low, but it will buzz all over the place on the first few frets. A truss rods only purpose is to adjust relief, action is a different adjustment. I have a Danelectro 59 DC that was reissued in the mid 90s, I bought it new and have taken good care of that instrument. Sometimes it is perfect, sometimes it is almost unplayable because it does not have a truss rod, just a reinforced neck. Those Martin and Danelectro necks may be fine for an area with a steady climate and humidity, but where I live it changes constantly, and a truss rod is a much better option.

 

[Turnaround]

Wood does not elongate to any significant degree with humidity, it swells laterally. If you are building a table out of oak, you'd better take that into account, but in this application it makes no real difference. And I believe most if not all woods have a pretty similar coefficient of thermal expansion as steel, that is to say, negligible for these purposes, so that is not an issue either.

Wood does react lengthwise to changes in humidity, not as much as it does across the grain, but it still does. And that's why bassists and guitarists are bringing their instruments to me for setups - the neck will swell in length slightly as the humidity rises, and against the constriction of the truss rod, the neck bows backward slightly. Conversely, when the weather dries out thew wood contracts lengthwise and thus is marginally shorter than it was, but the truss rod is not affected by humidity, so it is the same length. Thus the neck will have less tension from the truss rod and will bow up slightly under string tension.

Yes, the wood has a similar coefficient of thermal expansion as steel, but it's the humidity at play here, not temperature.