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.