Off In The Woods

The PIC light controller has been getting most of the attention over the last couple of weeks. I needed to be sure it was going to do what it said on the tin before things get too far. I didn't want to get the whole neck finished and then discover that the Pacman LEDs are too dim to be seen, or that the ghost flashing on and off induces fits to anybody within a 10m radius.

If I'm honest (and it's about time...) it had a lot to do with the fact that I really like flashing lights. I wanted to see if the whole animation thing was going to hang together, or if it was going to look a bit half-hearted.

I have tried to take a couple of pics, but my camera gets confused with things chucking out yellow light, so they look a bit grim. Once it is mounted in the neck, there won't be any stray light leaking out and it should have some more contrast. I didn't bother to take pictures of the dots, and the ghost part hasn't been done yet. I'm hoping that if the pacman works OK, then I just have to do the same things and the ghost will come out alright...

On a nerdy technical note, I am using a PIC with an internal oscillator (timing accuracy to within 0.5% should be good enough to see his jaw wobble up 'n' down). I started off governing the animation timing using interrupts which worked well for a short time and then it just stopped. If I changed the timer preload value, to set a different time between 'frames' it would go off in the woods at a different point (seemingly random). I could not get it reliable enough using interrupts, so I'm back to a good old fashioned loop that counts up to a big number before it carries on. Retro? or lousy programming? Who cares! It flashes lights!

Talking about wood, I thought it was about time to remember what the real meat and potatoes was all about. I decided that the headstock ought to get trimmed. I traced my original design onto another sheet of paper and stuck it on to the headstock. I had also previously marked (fairly unsuccessfully) the outline of the fboard with white undercoat. Pencil doesn't show up on Padauk and Wenge (well, not to my eyes).

The paper template was left to dry and then with a brand spanking new coping saw I set to work on trying to saw without going over the lines. I am sure sandpaper will fix it later...

I wanted a different looking headstock so I decided on a cross between a fish and a pretzel. Perhaps it is a fish flavoured pretzel. Does anyone make them I wonder?

It needs a bit of carving later to give it that overlapping look, and to thin it down a bit as it is still 20mm thick in most places.

Cheap flights

The truss rod has been made (thanks Eaton!), but the fittings at each end are still in the machine shop somewhere. Once it is completed the inside of the neck can be attacked once more, but until then I need to carry on with all the other stuff that needs to be hidden behind the fboard.

The fboard lights (these could be called flights!!) need to be built. The dots are pretty straightforward, but the pacman is going to take a little more effort. For the worlds first animated bass (as far as I know...) to get the flights looking decent. The lights needs to be in the right places and not in the wrong places. Sounds easy enough...

I have decided that pacman's body needs to be made up of eight 45 degree segments. The chomping mouth is then made by turning the West one off, followed by NW and SW. This sequence is going to be governed by a PIC microcontroller.

The tiny piece of pad-board holding the LEDs is shown here. These are surface mount 1206 LEDs which are large enough to be soldered with a normal iron.

The PIC is mounted on another board so that the code can be developed. The real advantage here is that as long as the PIC can switch each LED on and off, the sequencing and all the cunning stuff can be done later. The PIC will eventually be situated somewhere in the body of the guitar and will be fairly easy to get to.

Seven of the eight LEDs are lit so that pacmans mouth is slightly open (ie W off). It needs to have a piece of translucent acrylic over the top to even out the light in each segment, but I think it should be recognisable when its going.

At least there's no splinters involved with this work. I need to do the ghost illumination next, and the dots. Only pacman is animated, the other LEDs will just be on or off together (which should make the programming a bit easier to cope with).

It doesn't matter how long you've been an electronic engineer, you just can't beat a circuit that makes LEDs flash on & off.

Fantastic!

Sticking My Neck Out

The next job is to start getting the neck closer to the right shape. The neck laminates have to be fairly chunky to suit the body, but the neck is typically about an inch thick so some material needs to be removed. I don't have a bandsaw handy, so I have to do battle with a handsaw.



You cannot relate to what you are doing on the end of a power tool, and accidents (to wood and/or fingers) happen so much quicker and deeper. At least with hand tools there is plenty of scope to check that things are still going to plan. I feel a kind of respect when working with wood and it is a way of getting to know it. Let's all hug trees now!



Now that the hippy moment has passed, the starting point was to cut slots to around the right depth along the neck. This helps mentally by turning a lengthy job into smaller steps, and also keeps the depth more consistent over the length of the neck.






Once it was done (several hours of hard work) the finished result is starting to look a little more like a guitar - which is nice.

More Fboard

The fboard was taken back into work to use the milling machine one more time. The fboard was clamped up and a 1.6mm drill used to drill into the edge for the fret markers. These are going to be 1.5mm fibre-optic light guide to pick off some of the light from the main fret dots. I remembered to drill two holes at the octave marker and made sure that the dots were closer to the back face of the fboard to minimise the chance of the drill busting out the front. That would be a really bad thing at this stage.

Groovy

After some playing with the fboard it was time to return to the neck and in particular the truss rod installation. The truss rod is still being fabricated, but now that the fboard has a fairly defined length, the length of the truss rod groove is more or less fixed. I decided a while back that the easy way out was to fit a double action truss rod. The downside with these is the possibility of a rattle in the neck, which I have noticed on several other guitars, so I am going for the traditional compression rod in a curved channel.

I followed the method outlined in the Hiscock book which has a router running on curved rails to give the height change over the length of the rod. It was further complicated by the fact that the neck laminations are tapered, so I could not use the edge directly as a guide. I had to space the curved board away from the neck by different amounts along its length to give a surface parallel to the centreline. After some measuring & checking the router was fired up and the groove was cut.

I have noticed a *slight* warp in the neck. As long as it doesn't change it shouldn't affect things greatly, but to reduce the impact of wood waving about as the humidity changes I have cut an additional pair of channels for some carbon fibre reinforcement. I will be fitting 6mm diameter carbon pultruded rod supplied by Fibretech GB. The rods should keep the neck more controlled in all planes other than just reacting against the string tension, so any further warping will hopefully be reduced.

More Fboard Work

On the fboard front, the small dots need to be 6mm discs. I cannot cut circles out freehand so I had to find another way. I had some 6mm steel bar that nearly became a truss rod so I have used it as a former. Rough cut tinted acrylic sheet was superglued on the end of some lengths of rod, and then finished off on a belt sander. The same technique was used for the other shapes, after other formers were made. The discs are still proud of the fboard surface, but that can be sorted later.

I still need to make pacman and ghost shapes to fit under the tinted perspex...

OK - Pac it in

I give in. I really was trying to avoid dots on the fret board, but I think that any other shaped marker will be very tedious after the first two or three have been done. Just dots on their own would be too 'ordinary'.

The whole point of making your own bass guitar is that you can create something that wouldn't be available off the shelf. So I am doing dots with a slight difference - Pacman style!

Pacman

As a youngster, I remember the first computers that I got to play with at secondary school which were Commodore Pets. We spent a few lunchtimes typing in games from magazines and always got unexpected results. I asked around and eventually understood enough to write enough BASIC to make a blob move about. This was developed over time into a really sluggish version of Pacman - 1MHz processors do not rock. I was well chuffed!

Anyway back to the plan...

Here is my paper cutout version of pacman, a ghost and some pac-food (or whatever the dots were called in the game). OK, it is a very thinly disguised excuse to get dots on the fboard whilst not losing too much face, but I like it - and it is more fun than my previous idea of a Penrose Triangle.

I like the idea of having pacman et al, but it is a bit inyerface all the time, so I want to make it a bit more-umm-controllable.

A few years ago, a local band, The Mafia, had all their gear stolen. That was about as bad as it gets for a gigging band, and many would have just thrown the towel in, but they carried on and have even paid off the loan. The night they were due to play, they phoned up a mate whose name totally escapes me and he turned up with a couple of guitars and some backing tracks. He was great, but the thing that impressed Chewie and me most (sad, but true) was the blue illuminated fboard dots.

Needless to say, Chewie's Ibanez bass is going to be getting some illuminated dots once the truss rod is repaired (currently in a machine shop). The old dots got mangled with the acetone trick, so some work would be needed anyway, but lights just make the whole experience more worthwhile.

So for moonbassalpha (which still has nothing to do with moons) I am also keen to illuminate the fboard, but having some electronic knowledge makes me want to go that little bit further. I want animation! I want pacman to chomp, I want the dots to move, I want the ghost to get angry, I want strawberries to appear at random. OK, no strawberries, that is a step too far.

Firstly the fboard has to be drilled. This was another job for the milling machine at work so I could be sure to get the dots in a straight line. I left the fboard on the slot cutting MDF to support it. The food dots are 4mm holes with a 6mm counter bore. This gives a ledge for perspex to sit on later. The pacman is 20/22mm and the ghost has two holes 16/18mm, one above the other.

I have chosen some tinted perspex, and the theory being that with the lights off, it will look like an ordinary plain fboard. With the lights on it will look like 1982 all over again...

Fret Ye Not

I've just put the finishing touches to the fret slot cutting contraption. It is something that has evolved over the last few weeks so that the fboard can be slotted. I know you can buy them already slotted, but I wanted a zero fret, and a blank bit after the 22nd fret. Talk about fussy - no maple, no dots, weird fboard...









A took a trip to the local B&Q depot and got them to whizz their circular saw on some 3/4" MDF so that I had a thin piece with straight edges. This can move left and right without moving too much in any other direction. I was originally thinking of using a handsaw, but I had trouble in finding a blade thin enough - then I remembered the Dremel I used to savage Chewie's Ibanez fboard.



I took the centre strip to work and used a small milling machine to drill holes at 34" scale increments. I had a bit of help 'dialling' the piece in so it was straight along its length (Cheers Alan!). Then I got down to business.

The mill didn't have a digital readout, so I had to keep saying the measurements out loud so that I didn't forget where I was. The measurements were checked and another set of holes drilled to see if they fared any better. They seemed closer so I went with them.


More tweaking on the fixture and several dummy runs on scrap wood and it was ready to go! It looks a bit Heath-Robinson, but as long as I did't try and saw it all in one go it did the trick. One or two of the slots are a bit messy, and most of them have a slight curve at each end, but if I get big enough frets they will cover it up nicely!

You can see the locating peg in the last of the top row of holes. The bottom row was the first drilling attempt, so they are just for cooling now ;-) .

I still don't know what to do about position markers. I'm still trying to avoid dots.

Leaving the Splinter Group

First and foremost, the wenge splinter has now left the building. It took two weeks to work its way out! I managed to oik 2-3mm out not long after it had happened, but the remainder was stuck in too deep. The last 4mm came out today (during dinner, what good taste). I now have a hole in the side of my finger, but I am sure it will sort itself out given enough time and cups of tea...

The F word

Fretboard, fingerboard, I am sure they are the same thing - unless you're making a fretless ;-). The f-board started out as a sawn plank of ebony around 3/8" thick. It needed to be thinned down to around 5-6mm so out came the trusty plane again.

Planing the edges was no problem, but the top and bottom surfaces were not so easy. It could be because the wood is wider than the plane blade and so it starts to tear at the edges. I spent some time resharpening the plane, but it still caught and gouged out nasty holes here and there.

Once it was close enough to the finished thickness I carried on with sandpaper around a block. This covered up most of the plane incidents like a spokesman for the aviation authorities.

The biggest problem with the fboard is getting it flat. I must use the plane awkwardly as the smooth board was straight along each edge, but had a definite twist along its length and would not sit flat on a surface. I had not planned on making a torzal twist bass!

I had to selectively plane and sand more material off in places to achieve reasonable flatness (not perfect, but close enough for jazz...) and hope that when it is finally stuck on the neck it will all come out alright.

I eventually trimmed the width down to around 1mm over the finished size and it is now mostly flat. I was impressed with the feel of the wood, it doesn't have flakey fibrous bits hanging out of the end grain - it almost seems like a plastic and can be finished off very neatly.

Another fancy of mine is that I don't want fboard dots. I like them on the edge (so I can see them), but I don't want them on the fret surface. I quite like triangles & squares, but not dots. Everybody has dots. Dots are everywhere. I suppose a 12th fret marker would be nice, but not a dot. Not two dots either. Don't even think about colons: