The Good, The Bad And The Ugly

Now the fboard is on I really wanted to know an answer to one of the "you-won't-know-until-you-get-there" questions. During the initial sketching phase I was trying to achieve a blend of visual balance along with a mechanical balance.

The visual balance has had one or two detours along the way but I am still quite happy with the its appearance. The mechanical balance has always been something that would be hideously lengthy to try and calculate to any degree of accuracy and just isn't worth the effort.

So now the bass is in one piece I thought it would be well worth slapping some of the major components on and try it out. First up was the strap buttons. I must admit I was not foreseeing any difficulties here, but the way the top horn curves downwards required a short drill to avoid the neck being in the way. The Dremel just about squeezed in!

The Hipshot Type A bridge was marked out as accurately as possible on a guitar with no straight edges or a centreline and fitted with the supplied self-tapping screws. It looks good, though part of me wanted to fit a thick brass plate on the back and use bolts to clamp the bridge on more firmly. Maybe one day...



As can be seen above, the volume controls and pick-up switch have also been fitted temporarily. These are not wired up yet, mostly because the pick-ups are still in a box.

The Schaller M4 series tuners were fitted onto the headstock. On the original sketch the tuners were angled in sympathy with the headstock outline. In practice the tuners have a worm drive that can be above or below the main tuner shaft.

If I swap the tuners over from left to right, there is sufficient room to angle them and get my fingers in without bashing my knuckles on the wood. The downside is that the tuners operate backwards which will seriously do my head in over the passage of time.

The tuners were put back to normal and straightened up. This comes under the heading of bad as I am sure with more planning this could have been resolved, but it is just going to have to stay that way now.



The control cavity plates were recessed into the back of the bass. This is the ugly part. The cutting of a curved outline with a straight chisel across different woods was always going to be a bit fraught, but the end result is quite scruffy.

I would like to present a whole range of excuses, such as "it was too hot" but it was largely impatience. I wanted to get this relatively dull part finished so I could move on to something more interesting. Fortunately it is on the back and the careful photography hides most of the undulating gaps. The brass covers were fixed with any available screws, but will eventually will be finished off with a shine and fitted properly.

The two AA batteries just about squeeze into the top control cavity, between the switches. The animation circuitry and LEDs are still working.



Once all these jobs were done, a strap was fitted and the bass was tried out in a stringless fashion. The overall balance was quite good - not particularly nose heavy, but fitting a large brass nut could change that to some extent. It seemed quite happy sitting at the usual 30degrees.

The tuners, bridge and strap buttons will have to be removed again before the neck is shaped to prevent them from getting damaged. Fitting them again will be much easier as the holes will be already in place. I've still got to try and cram the pickups onto the front of the body without fouling any of the switches & pots hidden underneath. There's only one way to find out...

Bodywork

Before the top section of the body is joined to the neck the remainder of the control cut-out was marked out (on the neck) and then removed with a drill and chisels. Before the two parts were mated together a paper tube was wrapped around the wires that go between the control cutouts so that the wires don't get covered in glue. One day I may need to carry out some repairs so I need the wires to be changeable.



After the cutout was done, it was time to get back to the glue and clamps. Fortunately I had already dowelled the join so there was little chance of the parts drifting out of alignment, but a good dose of pressure helps keep the joint gap under control. The neck side of things was straight and flat, but the mating face on the body had a slight curve across its width (due to my lop-sided sanding). As it was pretty good along its length I decided to leave it alone instead of risking a compound curve.

Getting all the wires through from the neck LEDs was a tight squeeze, but hopefully that means it won't rattle later on...



Once the top part was fastened on, the same process was applied to the lower part. This was a lot easier as there is no wiring going on down there at the moment. The control cavity was finished off and I made sure that I can get the pickup switch in.

The brass cover plate was fitted over the PCB once all the LED wires were plugged in and a temporary battery holder tucked in. The animation part still works!



Clamping and gluing the lower part. The fboard is still protected by tape in case I have a further attack of clumsiness.



After both bosy sections were glued into place the surfaces were blended together. The front and back had to be planed with a small jack plane and finished off with sandpaper. The upper and lower horns fade into the fboard using a round surform and more sandpaper. Finally the bottom of the guitar (ie below the bridge when it is standing upright) has had its curve finished off.



It is good to be able to pick the guitar up normally now and sit it on my lap. I need to think about a stand. I have a couple of stands for my other guitars, but these have fairly conventional shapes. MoonBassAlpha will need an angled stand...

Fretting

The fboard has now been levelled along its length and cambered across its width. The fretwire I am using is straight. This needs to be radiused a bit tighter than the fboard camber so that the frets will sit properly when they are hammered in. Bending the fretwire by hand will probably result in very uneven twisted frets so another gadget needs to be thrown together.



The fret bender is a board with three ball bearing races on it. The fretwire is drawn back and forth whilst applying pressure to the third bearing mounted on a bracket. It did the job OK and all three lengths were ready for fitting.

Before the frets were slapped in, I had to get the width of the neck wood to match the width of the fboard. It was originally left oversize so that the placement of the fboard on the neck wasn't too critical, but now that is fixed the excess material can be removed. I used a small 7" jack plane to remove most of the Padauk and finished off with coarse sandpaper. The back of the neck will be shaped later, but it is good to start getting the neck close to its finished size.

The newly uncovered wood is quite brightly coloured and shows how some of the previously exposed Padauk has aged over the last few months. The picture also shows that the small fret marker dots have almost disappeared, but the ghost and pacman are reasonably visible.



A practice fret was bashed in an offcut of the neck wood and seemed to go in without breaking or splitting the wood.

The first fret went in at the body end. I don't tend to play much at that end of the guitar so if the first few are a bit lumpy it won't be too serious. The technique outlined in Melvyn Hiscocks book was used - ie cut oversized, tap the ends in first, followed by the middle, and this seemed to work fine.

After a few frets it became apparent that the camber on the fboard was not as uniform as it should be. The edges had a little too much taken off, giving a change of radius. This resulted in the frets sitting down nicely over the central three-quarters, but the very ends were slightly proud. More tapping, bashing, thumping, & drifting did not make this any better and re shaping the frets to include a change of radius sounds difficult, time consuming and will probably result in an instrument that feels wrong, so they were left alone.

After all the frets were fitted, the ends were trimmed with a Dremel with a small grinding wheel. Some of the fboard gap filler (PVA/paint) was used to fill the visible ends of the fret slots top and bottom. The slightly proud frets were treated to some superglue to ensure they remain in their position and do not relax or fall out at a later stage.

The zero fret was not fitted at this stage as the frets still need to be levelled or dressed. This needs to be slightly higher than the others so it needs to be hammered in after the levelling has been done.

Iron Maiden Rocks!

What a good gig!

Chewie & me booked a couple of tickets about 6 months ago to go and see Eddies mates. As luck would have it, Mayfield & Bruce were going too, so we managed to hitch a lift to Twickenham with them. Their tickets were for seats, ours were standing in the madding crowd. At the time I would have given almost anything for a seat, but you get a better view down in the thick of it.

The support acts did alright, but didn't seem to connect that well. The IM boys (ok, not boys, they must be well into their 50's) did a great job belting out all the 80's classics including Aces High, The Trooper, Revelations, Hallowed Be Thy Name, Powerslave and even the lengthy Rime Of The Ancient Mariner to name but a few. Oh, and not forgetting the song about £6.66 of phone credit!!!

With the IM gig fresh in my mind, I was soon back to working on Moon Bass Alpha. This doesn't really count as useful, but I had to give it a go:

I was talking to Pete (who regularly beats me at badminton) about the origins of Moon Bass Alpha from the old sci-fi series Space 1999 (another funky bass-line to use one day). It's lucky I wasn't thinking of the Muppet Show at the time or I could be developing a Gonzo Bass.

OK, back to the plot. Everything was now glued inside the neck and the various LEDs were tested. The alignment betwen LEDs and fboard was also checked so it was all ready for the next big step of sticking the fboard on. This is one of those times that requires a drum roll.

It's a bit final, and if it doesn't work once stuck together it will be a bad day indeed. The good news was that the fboard was placed in the correct position and the LEDs all worked afterwards.

The bad news was that the fboard didn't seat down evenly along the length of the neck. There was definite high and low spots with over a millimetre between them, and quite a few gaps along the edge. This was a bit unexpected as I had used several clamps and a block to spread the load. With the benefit of hindsight I think that the fboard itself is a bit too thin, and that sanding the radius onto the top is best left until after it has been glued on. Next time...

The following photo is carefully staged to avoid showing those bits (but I know they are there).

I decided to put the tinted perspex 'windows' over all the LEDs before I start filling and sanding. All the perspex shapes had been cut earlier and all need to be sanded flat once glued in. A small amount of clear superglue did the trick for all eight pieces. These lenses were rough sanded back down to about the same level as the ebony.

A mixture of PVA wood glue and water based blackboard paint was used to fill the gaps along the edge of the fboard and around the perspex lenses. This has a tendency to sink back in places, so these had two or three layers built up. This was then given a final sanding down the grades using a 1m rule as a straight edge and eventually finishing off with 1200 grit paper.

Looks like the fboard is ready for the 'f' s.

Cut It Out!

Before the neck and body get joined together I need to make some space for the circuit board, switches, voulme pots and batteries. I started by drawing out the shape of the covers on paper making sure they will fit in the little space there is left. The covers were then fashioned out of brass plate and could then be used as templates to mark the wood. The first one to try was the space for the PCB, and it is going to have to live in the upper horn. This is as far away from the pickups as I can reasonably manage to keep any interference noise to a minimum.







The controls for the animation are also in the top part of the guitar and are going to be inside the top cutout. This leaves the guitar with fairly clean lines and the minimum of clutter (unlike my Vigier!). There is a toggle switch (Bright/Off/Dim) and a push button (Animated/Static) which are usefully placed to my mind.



On the lower half of the guitar the pickup wires will eventually be routed to a pair of volume controls and the mother of all switches. This toggle switch took a while to track down and is a 4-pole, 3-position, on-on-on switch. In short, I can wire the switch so that I can have the coils from each pickup in series, parallel or just a single coil. This gives some variation in the tone, whilst keeping the controls simple. I don't want it to become too complicated...





Once the switching and volumes have been taken care of, the signal is routed to a 1/4" jack socket. I am using a Neutrik socket as they are really well put together. The hole for this was bored using a hand brace and bit. The recess for the mounting flange was chiselled out and the fixing holes drilled, as well as a connecting hole between the back of the socket and the volume / switch area.




The neck is still being built up. The carbon rods have been stuck in with epoxy resin. I didn't think that wood glue was going to do much with carbon! After them, the LEDs fitted onto veroboard were tacked into place with a dot of superglue and the fboard tentatively placed on to check the alignment. A amount of adjustment was required and then this was bonded into place with wood glue, contact adhesive and superglue (mostly due to me hedging my bets on what is going to work best!). This needs to be thoroughly set before I verify the LEDs are working and then it will be ready for the fboard to be stuck on.

Trust Rod Fitting

Now is the time to fit the truss rod (or trust rod, which I feel is more apt, as I am really hoping it is going to work!). The aluminium anchor piece needs to sit under the fboard near the headstock. A hole was chiselled out for it carefully. I have to remember that the neck will be shaped later, and that getting carried away with chiselling could result in a weak end, which is the sort of thing to be avoided at all costs.

The anchor piece slots in OK.

The same sort of thing was done for the adjustment end. This one had to be done even more carefully as it will be visible after the fboard is stuck on. A couple of 30mm screws hold in the nylon bearing block. This had to be penned black as it too will be just about visible. The trust rod was covered with some 6mm heatshrink sleeving and a little oil before it was commited into the chamber of doom, er, the truss rod channel.

Everything was checked & double checked and then it was time to fit the wooden fillet that has a curve that matches that of the (chamber of doom) channel. Lots of glue and clamps as per usual.

Put to one side and allow to dry - and here's one I made earlier. Aaah a Blue Peter dream sequence!

When the glue had dried, I cautiously wound up the tension, looking for a bit of backwards curving. Disaster! As I wound the tension up, the neck started to show a small amount of forwards bow, ie in the same way that would be caused by a set of strings.

Smeg!

Due to the amount of tension I put on the neck, the anchor piece had also started to migrate south for the winter. Whilst I puzzled over what seemed to be a loophole in the laws of physics, I thought I had better strengthen the anchor piece to neck connection with some additional blocks of wenge. This meant losing a small amount of the channel intended for the carbon stiffening rods, but this was more essential. Some M5 washers were also 'drifted' into place just to help out.

Well, here's my theory. Ahem.

The neck currently is not shaped, it has a rectangular cross section. Because of the amount of channels cut into the top, the absence of the fboard and the extra thickness and girth of the neck it is not only much stiffer than a standard neck, but the stiffness is predominantly underneath the trust rod. When the rod is tensioned, although the curved channel should cause a backbow, at the present time with the greatly increased rigidity of the material under the rod, the top of the neck is more likely to be compressed causing a forwards bow.

This seems to make sense, but I cannot do much about proving it until the neck is a lot closer to being finished (ie back coarsely shaped, fboard stuck on). This is another reason why we all have to Trust In Rod.

Go Naked

Looking at the size of the veroboard layout for the MoonBassAlpha animation circuitry and then looking at all the cutouts that I have made in the body, I soon realised that there was nowhere for the electronics to live. A PCB needed to be knocked up to keep the size as small as was practical. The board was designed using CADStar, which is too powerful for its own good and will let you to make quite fundamental errors if you wish. I finished the board off with my customary "its close enough for jazz" air of carefulness...

I was tipped off about a local PCB manufacturing company Spirit Circuits who offer a cracking free PCB service! I am sure it is for legitimate prototype work where they hope to get repeat business rather than homers, but I'll just have to placate them over the coming months. The idea is that they supply a one-off board with the copper tracks and drilled holes, but without any silkscreen legends or solder resist mask. This is why they call it "Go Naked".




The finished board looks a bit lost in their A4 paper sized panel. Once it is cut out then construction can begin. The smaller parts are placed first and it soon becomes apparent that fine surface mount parts on a board with a ground plane really does need solder resist. It is quite tricky to avoid shorting things out with only a 10thou gap.



After the small stuff, the meter was brought out to verify that there were no short circuits and then the larger parts were slapped on. I mananged to incorporate a few cock-ups into the board design (no surprise there) which required one or two upside-down components and a couple of after-thoughts tacked on in precarious places.

The board was ready to try out and I needed to see how noisy it was going to be. Very few guitars have animated fboards, and probably even fewer have switch-mode power converters to power them. The lights take around 100mA from a 5V supply and running this from a 9V battery would make it a rather short-lived affair. Much higher capacity can be found from AA rechargeable batteries, so the MAX856 converter takes this 2.4V and changes it to either 5V or 3.3V (which gives a neat choice of brightness levels).




After a few more modifications, the board is not putting out too much noise. It needs to be kept away from the pick-ups as far as possible, (distance helps) and 3V3 operation is much quieter than 5V. All-in-all the amount of buzzing and whistling that makes it to the pick-ups is pretty small, and won't be noticed when everyone's playing. For recording use, I could just turn the lights off...


The Trust Rod Ends

At last the rod ends have been finished. Many Thanks to Keith at Eaton for knocking the brass adjuster up in his, er, lunchhour. This really looks good and will be seen somewhere at the end of the fboard once I channel out a place for it to fit into. It is going to run in a nylon block. This should spread some of the compressive force back into the wood and turn more smoothly than just a manky old washer alone.

The thread gets a bit tight in the middle - possibly it was tapped from both sides and didn't meet exactly, so I need to drill part of the thread out from the large end. It will still have a good 12mm of thread remaining.

The adjuster is based on the ones used in the Ernie Ball MusicMan range of basses. This seemed a much more elegant way of adjusting the rod instead of trying to find a hex-key down a tunnel like most guitars. I couldn't find one off-the-shelf at the time though I am sure somebody makes them somewhere.



The other end of the rod has got to be anchored into place (somewhere under the first fret or thereabouts) with this interesting shaped piece of aluminium fashioned by me using the milling machine at work. Hmm - functional, but it is probably just as well it won't be on display.



I hope all this fits...