I have been away from this forum for some time so I thought I would add some help for people building an instrument for the first time.

I will also be away from this forum for some time again as my internet sucks on my only device (my phone) until I can afford a laptop or a tablet.

The most common problem I see in here from people building an instrument for the first time is one of intonation.

Let me explain briefly the problem of intonation issues. You tune a string (or many, but for simplicity sake let us deal with one) and as you play each note on the fretboard it goes out of tune either on the first fret or it gradually gets worse with each note as you go up the fretboard. Sound familiar?

Ok, fair enough, these are hand built instruments and you might expect it to have a little bit of musical 'charm' but this just isn't supposed to have this type of wild departure from the musical scale! The first reaction is to shout for a bit of help from the members in here, this is a good idea. The members in this forum have been there, done that, got help, fixed similar problems, read the books, wore the T-shirt, eat the hamburger, bought the ticket and took the ride too. Same as you. Same as Me.

So here we go.. Lets not just fix the problem.. Lets understand why things and strings and musical scales are what they are and why sometimes they are not what we expected them to be.

http://hep.physics.indiana.edu/~rickv/Standing_Waves_on_String.html

Ok. What we see here is the second harmonic of an open string. its not too complicated when you understand what is going on. I'm like you.. "F**k sake, here we go on the techno-babble physics.."

Well, no. I don't like all that stuff either. I like the feel and the sound that comes out at the end. BUT.. I got to understand all this and hope to explain it in a friendly way.

Have a look at the diagram. L = your string from the nut to the bridge. When its plucked it makes the note that its tuned too. It has two points (these are nodes) at the nut and the bridge. It can be any note so don't worry about tunings and stuff as it is as important as a flees bum.

Here's the thing.. MUSICAL SCALES ON ANY STRING ARE BASED ON DIVIDING THE STRING BY 24. (this is 'mostly' true and I choose to not be overly "bla bla bla" )

Now.. see that middle node, it halves the string. It also doubles the frequency of the note. This is the second harmonic and its also the next 'same note'. Imagine playing a piano from a note up by 7 white keys and 5 black keys. Or.. by singing "doe a deer a female deer, ray a drop.." etc. You arrive at the same note but.. well.. the next one up.

That middle node should be (almost) at the same place on your fretboard as your 12th fret. (there are 12 half tones in a scale). When you play your 12th fret it should be the same note as your 2nd harmonic. (that middle node) It is quite easy to learn how to play a harmonic but I won't go into that here, google it, have a look on youtube.

This is the essence of adjusting and correcting Intonation by moving the bridge backwards or forwards until the harmonic node is the same note as your 12th fret.

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Now that should be that but...

"yeah! Its done!.. no wait.. it still isn't quite right! arghhhh!"

Its at this point that you should throw the dam thing in the bin..

Just joking, I've been at that totally frustrating point in the build and thought.. "what the f**k?" and I did almost throw the thing in the bin. so.. here's something else to think about. "Is my nut in the right place?"

You can check this out quite easily. Grab a capo (you can make one with a small bit of soft wood and a rubber band) and stick it on the first fret. Now.. that changes the two original 'nodes' of the open string = L.

Do the thing again with moving the bridge and the 2nd harmonic (this will be a bit further up the string) with the 13th fret. Remember that the middle node is 12 frets up but you have a capo on the 1st, so the node will be the same note as the 13th fret note.

Keep that capo on. How does the guitar sound up and down the fretboard now? (this is the same as having a zero fret instrument)

If its ok, then your problem is now with the bridge position (or the height of your strings, but you will know because it will be really hard to play it, have a look at lowering the string height).

This part is tricky because it involves a little maths. Measure the string size from the point of the 1st fret to your bridge in millimetres, mm, and divide it by 0.944.

If your harmonic and your 13th fret is good (with a capo on the 1st) then whatever number you have on the calculator should be the distance from the bridge to the nut.

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There are things to consider..

String height being the first.. high strings need to be stretched down to touch the fretboard and this raises the notes (on a side note, a good builder can fret an instrument to compensate for this by changing the spacing of the frets for that instrument. Think about a moveable fret after build, then marking the correct position)

Wonky fret boards.. yep, we all have built one that wasn't quite right. its not the end of the world. Just back to the workbench for either rescuing or turning into a slide guitar.

I'm sure there is another one (insert here)

Lastly.. There is no 100% correct fretboard on any of your £1000 Fender Les Strat'o'paulies.. You can buy new micro-tuned fretboard replacements these days sure, but the principles of having straight frets are in essence wonky by design. Sad but true. Part of the fun of building a handmade instrument is having a guitar that is 'charmed' with slightly off note perfection.

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I hope this small guide is a help to someone.

It is also a short farewell for a while to everyone in CBN until I manage to get my s**t together. Hopefully I will be back to 'abnormal' in a month or 3.