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Do-it-yourself Bass Guitar kit Building your own guitar has a real attraction for many musicians. But normally, left-handers are left right out! Here’s a complete kit that comes with all the parts needed to build, string and get playing your own electric or bass guitar. I f you’ve been frequenting the internet lately, you may have noticed a lot of advertisements from Banggood and similar outfits, of interest to readers of this magazine. Most of the items are electronic gadgets but recently I started seeing intriguing ads for DIY electric guitar kits. These provide you with all the necessary wood, electronics, strings etc; it’s then up to the purchaser to do the assembly, nut and bridge adjustments, connect the internal electronics and so on, but most importantly, apply the finishing coat to the woodwork. One common query I noticed was: “Do you make left-handed versions?” and it was clear from the sometimes nonsensical answers that the good people at Banggood had no idea what was being asked! I play left-handed and after doing Some of the parts included in the kit, from left to right: pickguard, two pickups, bridge with saddle, volume & tone controls, nickel-plated strings, tuning pegs, assorted screws plus nuts and backplate cover. 68 Silicon Chip Celebrating 30 Years some research, I found that the only company who appear to offer lefthanded bass kits are Pit Bull Guitars (www.pitbullguitars.com), based in Western Australia. I also discovered that, once exchange rates and shipping are taken into account, the Pit Bull products work out to be only slightly more expensive. But Pit Bull offer a much bigger range of models and build options, plus you get the benefit of local, English-language backup. They even host a builders’ support website: www.buildyourownguitar. com.au/forum Pit Bull’s main line of business is supplying fully-finished guitars to music shops in Australia, but clearly they thought there was also a market for enthusiasts who wanted to “roll their own”. So they appear to be just supplying the same kit of parts that their Chinese factories use to assemble their fully-finished products. There are a few other places in Australia who also offer DIY guitar kits, but none appear to have anything like Pit Bull’s range. I’ve always wanted to own an electric bass but left-handed models of reasonable quality are hard to come by and not particularly cheap. Pit Bull have a range of 14 different left-handed guitar models, including three basses, and I chose the JB-4L, “inspired” by the Fender Jazz Bass, as played by siliconchip.com.au By Keith Walters Michael “Flea” Balzary of the Red Hot Chili Peppers. The JB-4L kit costs just $199 including shipping anywhere in Australia. So I clicked the appropriate boxes, hit the PayPal “Pay Now” button and Australia Post delivered it a few days later. It came adequately packed in a stiff carton with lots of ecologically-correct cardboard and paper padding. The screws were all sealed into pockets in one plastic bag with no identification; you have to work out where they go. All the other bits are sealed in their own separate plastic bags. There are also no real assembly instructions; Pit Bull suggest you visit their website for that. They do recommend you carry out a “mock build”, basically placing all the parts in their approximate positions to check that everything is there, but that’s pretty much it. I did all that and after confirming that everything was there, immediately started the assembly. There are actually four main parts to the process and there is no specific order in which they need to be done (although this is for a bass, the instructions are pretty much identical for a 6-string guitar apart from the extra two strings): A. Metalwork assembly, basically getting all the mounting screw holes in the right places B. Fitting and wiring up the electrical parts siliconchip.com.au C. Painting or otherwise finishing the woodwork D. Adjustment of frets, action and intonation. In my case I did them in the order above, which gave me a presentable guitar after step C. To be honest, if I’d know how little time step D was actually going to take, I probably would have done it A-B-D-C. Normally, you would want to leave the finish until last, to avoid damaging it. The first thing you need to do is attach the neck. Some people recom- mend temporarily clamping it in position when you’re getting the rest of the components lined up, but I can’t see any real value in that, at least with a bass, so I decided to screw it into place immediately. The neck comes pre-drilled with four holes, and you first have to drill matching pilot holes in the body, which was where I ran into my first snag... There is a metal backing plate that the screws are meant to pass through to spread the load. I left that off during The neck of the guitar is attached to the body via a bolt-in joint, with four holes drilled through the body. This type of joint is quite strong, fairly easy to produce and doesn’t require glue. Celebrating 30 Years November 2017  69 Preparing the holes for attaching the bridge (left) and one of the pickups (right). The bridge is the sheet of metal that is secured to the body, while the saddle is attached to the tail-end of the bridge and the strings then sit on top of the saddle. The type of bridge/saddle combination used in this guitar is called a Tune-O-Matic bridge. It is adjusted by tightening or loosening the screws, thus altering the tension the springs apply on the strings. the drilling because I didn't want to scratch it, and when it came time for the assembly, I encountered this: The screw holes on the backplate that thread through to the neck didn’t align properly, as shown in the photo below. I mentioned this on the forum, and another builder making the exact same “lefty” bass reported he had the exact same problem! So somewhere in China is a jacked-up drilling jig. Anyway Pit Bull say they are looking into it. To be fair, they probably don’t sell all that many JB-4Ls, and nobody has reported similar problems with other models. Fortunately, I found some bamboo skewers that were exactly the right size to fill the erroneous hole, and after gluing one of those in there I soon had the neck re-drilled and properly attached. The next stage is fitting the bridge. There are various techniques described on the forum. I decided to use some cotton kitchen twine, normally The backplate had one misaligned screw hole, which meant that the hole had to filled and then re-drilled. 70 Silicon Chip used for tying up roasts and the like. I used this because it doesn't stretch and used Blu-Tack to secure two lengths of the twine behind the nut. I marked the position of the 12th fret with a Texta pen, and then doubled the twine back and marked it where it passes through the nut (it's better if you can get someone to help with this). That way, the first mark should be at exactly half the scale length, and the second should be twice that (the actual required scale length). We need to measure the scale length as it’s used to help set the location of the saddle on the bridge, once the strings are attached. I added some weights to the other ends of the twine so it hung over the end of the body, keeping the twine taut. The reason for this is because the distance from the 12th fret to the nut is the same as the distance from the 12th fret to the bridge, plus some compensation depending on the type of bridge and other factors. Then it's a simple matter of dropping the lengths of twine into the relevant slots on the bridge and moving the bridge around so that the twine lines up with the outermost pickups, and the pen marks line up with the centred adjustable bridge saddles. I recommend you just drill two pilot holes at first to make sure the bridge hasn't moved, and re-check the alignment before you put the rest in. Unfortunately, I subsequently encountered another snag! Despite one poster on the builders’ forum stating that the bass bridge saddles should be centred exactly at twice the 12th fret distance as shown, it turns out for a bass, the bridge needs to be mounted another 5mm or so further away from the pickups. Otherwise you may not be able to get the intonation right. Editor's note: This is typically due to the total string length being longer than the scale length to provide a buffer distance (about the distance the string bends when pressed to the fretboard), and is typically done by having the saddle set at an angle. Intonation of the guitar Editor's note: we recommend doing the body finish before attaching The 12th fret is marked in black on two pieces of cotton twine and we use the total distance from the nut to this marking to calculate half the total scale length for the guitar. Celebrating 30 Years siliconchip.com.au the electronics/strings and doing the intonation, as you will need to remove them before applying the finish. Take for example the E string. You normally tune the guitar so that the “open” (unfretted) E string is tuned to, well, “E”. Then, when you hold the E string down at the 12th fret and pluck it again, it should sound 12 semitones higher, that is, E again, but one octave above the open frequency. The problem is, when you fret a string you’re both tightening it, which will increase its pitch, and lengthening it, which will tend to lower it. Normally, stretching wins out, so if the 12th fret is positioned exactly halfway along the string, the fretted note will sound slightly higher than E. You correct this by adjusting the individual saddles on the bridge with the adjustment screws. If the fretted note is too high, the saddle has to be moved away from the pickups. This is complicated by the string “action” chosen, that is, how high the strings sit above the fretboard, since that affects how much the string has to be stretched during fretting. The action is adjusted using an Allen key they supply, with the small screws fitted to the bridge saddles (see later). This does open a bit of a can of worms, because while lower action allows you to play faster and there is less intonation shift, it makes the guitar more prone to fretboard buzz if the neck is not quite straight or the fret heights are uneven. As it turned out, I couldn’t quite get the intonation correct on the E string because the spring around the saddle adjustment screw wouldn’t let me compress it enough. I solved that by simply cutting the spring in half! I have heard that if you use higher-gauge strings you need to move the bridge forward, but in that case, they recommend you put on a better quality bridge. There was still a bit of an issue with the over-winding that holds the brass stopper at the end of the string fouling on the bridge saddle, but I fixed that by putting a couple of nyloc nuts on as spacers. A bit feral, but it works! I am jumping the gun a bit here, because after fitting the bridge I needed to fit the machine heads before I could put the strings on! Lining the machine heads up is pretty easy; you just press the metal ferrules into the holes, fit the heads, line them up by eye, then mark siliconchip.com.au This photo shows the four tuning pegs attached to the headstock. The headstock is pre-shaped but does leave some room for a custom design. The small hole you can see where the headstock meets the neck is where the truss rod is located. This rod helps to adjust upwards or downwards tension on the neck. and fit four screws for each one. Here I ran into yet another minor problem. The “reproduction” screws they supply are a bit on the cheap and nasty side, and I had the choice of either risking stripping the heads or breaking one trying to screw them into the maple neck, or drilling bigger pilot holes and risk having them work loose. In the end I went into Bunnings and bought some much more solid-looking sheet-metal screws and drilled the pilot holes out to 2.5mm. They may not be as authentic-looking but they still look pretty good. After that you really need to get the pickups wired in. Conveniently, the neck and bridge pickups are slightly different sizes, and the neck pickup (red wire) will only fit in the cutout closest to the neck. The pickups are each held in place by four long wood screws, with springs fitted over the screw shaft between the pickup and the body to allow height adjustment. I simply fitted the pickups into po- sition (you have to feed the shielded lead through a hole in the body first) and then used the point of a hand-held 4mm drill bit to mark where the pilot holes should go. After that I drilled four pilot holes for each pickup with a 2mm drill. At first glance it might seem like a nightmare getting the screws and springs to stay together while wiggling the pickups into position. Actually it’s no problem at all; the magnets hold everything together nicely! The pickup wiring is pretty straightforward: the shields simply are soldered onto their appropriate pot metalwork, while the signal wires solder to the wipers of their respective pots. This is not the usual method, but since the Jazz Bass doesn’t have a pickup selector switch, wiring the pots in the conventional manner would cause interaction between the volume settings. But then another quirk revealed itself: the pots were wired in reverse of the normal action, so fully clockwise meant minimum volume! There are two knobs to control volume and one for treble. Initially the potentiometers were wired in reverse, so that winding clockwise would decrease volume. Celebrating 30 Years November 2017  71 It’s possible that whoever designed this guitar decided that since everything else in a left-handed version is a mirror-image of the right-handed model, the pots should be wired backto-front as well! None of my other lefthanded guitars are wired like this, so I re-wired it to the conventional configuration. Another point that needs to be addressed somewhere in the assembly process is the matter of electrical shielding of the pickup and volume control cavities. I have my doubts that this achieves very much, given that my other guitars don’t have this feature. There were suggestions about using copper foil but I simply painted the interior with “aquadag”, which is the graphitebased conductive paint they put on the back of CRT TV picture tubes. Jaycar sell a very similar product called “Wire Glue”, Cat NM2831. I then ran copper wires through the access holes and fastened the wires to the conductive surface with small screws. There is also a grounding wire that sits under the bridge metalwork. You just thread the wire through an already-drilled hole, strip off some of the insulation and screw the bridge bracket onto it. After that I fitted the supplied strings and used the truss rod to adjust the neck tension. The truss rod is adjusted with a supplied Allen key via a small hole behind the nut. There was initially a bit of confusion as to how this adjusts, but eventually I realised that there is a half-turn “dead zone” between the clockwise and anticlockwise directions where the rod turns with virtually no resistance, then become progressively tighter in both directions. The truss rod I received from Pit Bull was set for zero tension, which led to the middle of my neck curving up towards the strings. This meant that the truss rod needed to be adjusted to exert force in the opposite direction until the neck was straight, such that using a straight-edge the frets will line up to the saddle. Editor’s note: it’s important to note that typical fretboards for electric and acoustic guitars have a convex curvature with a radius of somewhere between 7 and 16 inches. So it’s important to differentiate between the neck bending up or down, and the fretboard not being flat when doing intonation. 72 Silicon Chip This is what the body of the guitar looked like after applying the first few coats of oil and wax finish. Many guitarists find it easier to play chords and bend strings due to this curvature. Finishing coat Once I’d done all that and gotten the intonation and action approximately right, I turned my attention to the actual timber finish. Instead of the usual approach of either painting or lacquering, I decided to use two products I’ve had great success with in the past: Feast Watson Fine Rubbing Oil and Gilly Stephenson's Cabinet Maker’s Wax. Both products are available from Bunnings and are not particularly expensive; plus they keep in their tins for years. These two products are meant to be applied to bare wood and give an old-fashioned low-sheen finish that’s quite unlike any kind of painted or sprayed-on lacquer. I’ve used these products for restoring a number of items of period furniture, and they are particularly useful if you’re not interested in doing a full restoration (which can drastically reduce the value anyway), but simply making the wood look “presentable”. I simply strip off all the old varnish, leave all the cuts, nicks, cigarette burns etc exactly as they are, and apply the above two products with 0000 grade steel wool (also available from Bunnings). Apart from the fact that I had some of both products already, there are a number of advantages: 1. There’s no need for pre-sanding; the steel wool smooths down all the imperfections, which produces a Celebrating 30 Years smooth finish, while preserving the “character”. But make sure to give it a quick wipe down to remove any leftover residue before applying the finish. 2. There’s no real issue with the finish quickly hardening or otherwise “going off”, so you can do as little or as much as you like each night, spread over several evenings. 3. Both products have a pleasant gum turpentine smell; they don’t smell at all “painty”. You could even work on it indoors, while watching TV! On the downside, it’s a fairly slow process, and the finish takes a couple of weeks to dry completely, but the results are well worth it. The grain comes up beautifully, the finish is surprisingly durable, and best of all, if it gets damaged, it’s pretty easy to repair (Pit Bull sell and recommend what sounds like a broadly similar product called “Dingotone”). If you want to do an actual paint, lacquer or shellac finish on your guitar, there is plenty of advice on how to do it on www.buildyourownguitar.com.au However, it is far from a simple task to do properly, similar to re-painting a car. And you have to face facts. However good you are at it, you’re still pretty much going to wind up with something that looks like a cheap Chinese copy bought from a music store. With the “antique” oil finish, nobody is going to know what it is! It’s worth noting that Flea of the Red Hot Chili Peppers mostly uses a custom 1961 "shell pink" Fender Jazz Bass, which appears to have had an extremely hard life. But not only is Flea clearly not interested in getting it siliconchip.com.au The guitar after applying the finish, with masking tape covering the fretboard to protect it from damage when doing fret adjustments. The tools below it are all exceedingly useful for this type of work and are as follows, from left to right: a radius gauge, 12-inch radiused sanding block, fret rocker (level-gauge type tool for measuring three frets at a time), set of diamond files, a fret-crowning file, fret hammer and rulers. refurbished, Fender also now sell the “Flea” Jazz Bass, with all the beat-up pink paintwork faithfully replicated! Back to building, the first step in finishing the woodwork is to remove all the metal hardware, placing the various pieces into labelled zip-lock sandwich bags with the relevant screws. I also removed the neck, but put two of the neck screws back into the neck and the other two into the body. That makes them easy to hang up between coats. I spent about 30 minutes each evening for a week applying the rubbing oil, then another week applying the cabinet wax. The instructions are on the cans, but basically you just apply the product by rubbing it along the grain with the steel wool, give it a half-hour or so to dry a bit, then polish with a soft cloth. You can put on as many coats as you like but after about seven you will not see much more improvement. The photo to the left shows how it looked about halfway through the procedure, which does look pretty good but I found it near impossible to take a photograph that does the actual finish full justice! siliconchip.com.au The end-grain is more problematic, because it’s a lot harder to get that smoothed right down, but it still comes out looking OK; certainly no casual observer would be likely to notice. There are various schools of thought about how the rosewood fretboard should be finished, but for my money, a single buff-up with cabinet wax is more than enough. Editor's note: typical fretboard woods like ebony and rosewood don't necessarily need a finish due to how much natural oil they produce, compared to drier woods such as maple, but it’s always something that can be done at a later time. Headstock design In case you’re wondering about the “hatchet-like” headstock, that’s how it comes from Pit Bull. For legal reasons, suppliers can’t sell exact copies of name brand guitars (Fender, Gibson etc). Apparently, it’s difficult to copyright the body shape, but the headstock designs are regarded as registered trademarks. There’s nothing to stop a home builder re-finishing his headstock to the standard Fender “Treble Celebrating 30 Years Clef” design and in fact blueprints for all popular guitar models are readily available on the internet. But because this is being published in a magazine, I’ve left the headstock as is for now. I’m actually intending to make my own design anyway, and I also didn’t want to run the risk of damaging something before photographing it! On that subject, if by any chance you ever manage to hit the big-time playing your DIY guitar, you may have to consider trading up to “the real thing”. While the leading guitar manufacturers generally turn a blind eye to copies of their products being played in pubs and so on, they tend to get a bit tetchy if they start appearing in music videos and on CD covers! Fretwork After you’ve gotten your guitar all assembled and prettified and so on, you should have a playable instrument, but the next thing that will need attention is the frets. The fret heights must be carefully aligned, otherwise you will get fret buzz where the string makes contact with frets it’s not meant to. This is a November 2017  73 Part way through shaping the frets. You can see a slight protrusion where not all of the markings have come off the crown of the frets, indicating that they are not yet all lined up. The frets crowned and polished with 0000 grade steel wool. The profile on these frets weren’t as circular as they could be, but they do the job well enough. The fret-levelling gauge (fret rocker) being used to show that these three adjacent frets are all level. 74 Silicon Chip Celebrating 30 Years highly specialised subject and is covered in considerable detail at www. buildyourownguitar.com.au If you intend to make more than one guitar, some of the specialised (and quite expensive) luthiers’ tools may be a reasonable investment, otherwise you can still get a surprising amount done with some of the more basic tools available online. A steel ruler, a fret flatness gauge (fret rocker), a lightweight fret hammer, a basic fret file and a 12-inch radiused sanding block are the minimum requirements. A cheap set of diamond or sapphire files can be helpful too. The radiused sanding block is similar to a standard sanding block except that the side where you attach the sandpaper has been machined to match the curve of the frets in the instrument you are working on. They are available in various sizes, but virtually all electric guitars use a 12-inch radius, meaning the frets match the curvature of a circle with a 12 inch (~300mm) radius. If you’re not sure, you can spend a few dollars more and get a radius gauge which is the pincushion-shaped thing in the image above. The basic procedure is to first take the strings off and get the neck as straight as you can by adjusting the neck truss rod and checking the flatness of the frets with the steel ruler. However, before you do anything I strongly recommend you tape up the fingerboard between the frets with strips of masking tape to avoid damaging the wood and to stop steel filings from getting near it. The photo to the left shows my bass taped up and ready for adjustment, the tools laid out below it and the Allen key fitted to the truss rod adjustment. After you’ve gotten the neck as straight as you can, the next step is to identify any offending frets with the fret gauge. The fret flatness gauge is simply a piece of steel plate cut with straight edges of various lengths that allow you to bridge just three frets at a time. If the middle fret of the group of three is higher than the other two, you will be able to detect this by rocking the plate. Starting at the pickup end, identify any offending frets and then carefully and extremely slowly reduce their height until the gauge can be laid across the group of three with little or no rocking. Actually, you can siliconchip.com.au Above: a close-up of the bottom side of the chrome tuning pegs. Right: close-up of the saddle showing adjustment springs. You can see the spring for the E-string’s saddle (the lowest one) has fewer turns than the other saddles as it was cut in half to help set the intonation correctly. start by simply tapping the offending frets down with the fret hammer. In some cases, that will be all you need, but usually you will need to use the fret file. The fret file is actually smooth where a normal file is rough; the roughened parts are cut into the edges (it’s a bit like a rat-tail file in reverse). You can get radiused fret files (crowning files) but they’re horribly expensive and require considerable skill to use properly. I must re-emphasise the “extremely slowly” part! If you overdo the filing on just one fret, you will have no option but to shave all the others down to match. Work your way along the frets, starting from the pickup end. When you reach the nut, re-check the overall straightness, re-adjust the truss rod if necessary, then repeat the entire process. You are unlikely to get all the frets completely level this way, so once you have the frets as even as you can get them, the next step is to lightly sand the frets using the radiused sanding block and some extremely fine (800 grit or more) wet and dry sandpaper. You can get fancy sandpaper specifically designed for this application but it’s not particularly cheap and I don’t see that it makes a lot of difference, although people will argue otherwise. The first step is to mark all the frets with a felt-tip marker. That way you’ll be immediately able to see which frets are being touched by the sandpaper and which are not. After an extended period of sanding and re-marking, you should get to the siliconchip.com.au point where all the frets get the ink taken off together, and at that point they are as level as you are ever likely to get them. The very top left photo on the opposite page was taken part-way through the process. You can see how the two towards the centre have a slight “dip” which basically means the rest of the frets will have to be sanded down to match. The final step is to carefully polish the frets with 0000 grade steel wool. This is where the masking tape comes into its own. You can’t expect to get these adjustments absolutely perfect if you’re not a professional luthier with all the expensive tools, but that will by no means make the guitar unplayable. It will mostly limit how low the action can be set. It will certainly still be plenty good enough for most people! The main difference between a fullpro job and what I’ve described here, is that with the pro job, the fret crowns will end up precisely semi-circular, while yours will be more trapezoidshaped. Generally, people have rated a well-built Pit Bull kit as roughly equivalent to a $500 “store bought” job, but with vastly more “street cred”! Setting the action Setting the playing action is simple enough, you just adjust the screws on the saddles to raise or lower the string height off the fingerboard. Of course, as soon as you do that, the tuning will shift and will need to be re-set. The minimum action height Fender recommend for a genuine Jazz Bass is Celebrating 30 Years about 2.4mm, but in practice you’d need the frets dressed by an expert for that to work without fret buzz. Setting mine to 3mm gave a satisfactorily fast playing action with zero fret buzz, and I doubt that the extra 0.5mm would make a whole lot of difference. With a guitar tuner, setting the intonation is really quite easy (I have a modern digital one but I still prefer my 1980s vintage analog Korg for this). You simply adjust the “E” bridge adjustment screw to the correct pitch while holding down the 12th fret, then re-adjust the open E pitch, and if necessary, adjust the bridge screw again and repeat as necessary. With my tuner, it was easier to simply “hammer on” the 12th fret, playing it like a piano, rather than plucking the string. In most cases doing this procedure just twice per string should be enough. Additional information You can get more information on the process of building and setting up guitars, or purchase tools to aid you, at the following websites: www.anzlf.com is an online Australian and New Zealand instrument maker’s forum; they also have a list of local vendors. www.stewmac.com is a fairly popular American-based luthier shop that supplies hardware, wood and everything else you could need to build primarily guitars and some other instruments. http://luthierssupplies.com.au/ is an Australian-based business which supplies luthiery tools and supplies. SC November 2017  75