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...