I recently built my first CBG without following an online tutorial. I used a fret calculator to make fret markings. (Measured from nut to bridge, scale to and from the 12th fret is perfect) I put the strings on before installing frets to make sure everything checked out. The intonation was spot on, the fretted notes were good. I figured everything was set and once I put the frets in I'd be good to go. After putting the frets in and stringing it up, the notes are ringing almost a half step sharp! Does anyone know where I went wrong? I've looked at a lot of different sites but I haven't come across anyone having the same issue. Can you help a guy out?
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"Build a new neck"? if it was me I might consider pulling out the old frets and just putting a new fingerboard on top of the existing one and refret it. But do not copy the old fingerboard layout.This could give you a better projected line to the bridge. You could adjust the new fingerboard thickness to suit the new projected line, or wedge shape or ramp it so it's not to high at the nut end.
Remember to add compensation to scale length at the bridge.
Cheers Taff
As I've seen problems with a couple of people trying to install adjustable bridges, I thought I'd do a quick rundown on what to avoid when fitting these bridges, in order to get a playable guitar.
Rob Lately > ChickenboneJohnNovember 12, 2016 at 6:07pm
Thanks for the info! I appreciate you taking the time. Trying to absorb all this and apply it to my next build. I decided to build a new neck altogether. We'll see how it goes!
Your string height may be too high and when the strings are pressed down they go sharp. Also check the scale (nut to Bridge) .
ChickenboneJohn > lawntrout guitarsNovember 12, 2016 at 10:13am
From seeing the photos, your string height is way (and I mean maybe by a factor of 4 or 5 times) too high to have any hope of intonating decently. At the 12th fret you should be shooting for 2-3mm (1/8 inch max) if you want to play it using the frets. With the correct string tension this isn't too low for slide playing either, around that mark should give you a happy medium.
With your bridge set-up it just isn't possible to lower it enough to make any meaningful improvement. It looks as though the neck is set in too low and possibly pitched forward - that's your problem. You need to take the neck out and give it some back angle, and/or re-fix it so that the fretboard is higher with respect to the top of the box. If you've glued the neck in, then I'd say leave it alone, move on and make another one, just fix it with screws next time. Every one of my guitars is fixed with screws through the back of the box - it means you can tinker with the action and repair them easily.
Hi Rob, there's not a lot more to say about your fretting issue, but heres one last observation. There has been suggestions re high String action causing the problem, but why I discounted this was the fact that you said that pushing the strings down without frets the strings noted true. So with frets installed the distance the strings travel is less, so I can't see them stretching sharp due to high action, if they did not before fretting. Just to confuse you more. I wish you lived closer.
Good luck, Taff
Rob Lately > Taffy EvansNovember 12, 2016 at 6:12pm
Yeah I'm at loss! I appreciate all the info and help. I brought the action down a ton via sanding the nut and dropping the bridge into the box and it didn't make a difference at all to the tuning. I decided to try to build a new neck with a different type of nut in it. Now I'm afraid to put frets in if the thing works well without them! Might just try wood burning fret marks in next time. Thanks again bud!
Rob, are you plotting the bridge position by measuring or by checking the harmonics at the 12 fret. Capo at the first fret to take out nut and test at the 13 fret, see what happens.
Taff
Fomhorach > Taffy EvansNovember 10, 2016 at 6:27am
Yeah. Capo the 1st and test the harmonic at the 13th. (Lightly touch and lift off just after plucking it) it should be very close to the fretted 13th note.
This is actually the best way to get the intonation set at the bridge because it eliminates any nut discrepancies. Also remember that every straight fret system (including fender and Gibson's) they are all 'not perfect'. If you can get the guitar sounding good with a capo, then the problem is at the nut.
If this works good, then set the intonation for the thinnest string with the capo on fret 1. (Using the harmonic at fret 13 and the note at 13)
Measure the distance from this bridge position to the first fret (in mm) and divide it by 0.94387. This will give you the length your string should be. I.E. the leading edge of the nut.
All this is reverse maths. When I build a guitar I don't worry muh about scale length. I get it all together, mark where I want my nut to be, mark where I want my bridge to be and multiply that length by 0.9438743127 for each fret. As long as you clamp your measuring tape and double check, your good to go. When you understand this method it makes checking nut spacings and harmonics etc fall into place. You begin to understand what your doing to the wood based on the viration lengths of the strings.
Replies
Remember to add compensation to scale length at the bridge.
Cheers Taff
image.jpg
As I've seen problems with a couple of people trying to install adjustable bridges, I thought I'd do a quick rundown on what to avoid when fitting these bridges, in order to get a playable guitar.
Your string height may be too high and when the strings are pressed down they go sharp. Also check the scale (nut to Bridge) .
From seeing the photos, your string height is way (and I mean maybe by a factor of 4 or 5 times) too high to have any hope of intonating decently. At the 12th fret you should be shooting for 2-3mm (1/8 inch max) if you want to play it using the frets. With the correct string tension this isn't too low for slide playing either, around that mark should give you a happy medium.
With your bridge set-up it just isn't possible to lower it enough to make any meaningful improvement. It looks as though the neck is set in too low and possibly pitched forward - that's your problem. You need to take the neck out and give it some back angle, and/or re-fix it so that the fretboard is higher with respect to the top of the box. If you've glued the neck in, then I'd say leave it alone, move on and make another one, just fix it with screws next time. Every one of my guitars is fixed with screws through the back of the box - it means you can tinker with the action and repair them easily.
Good luck, Taff
Taff
Yeah. Capo the 1st and test the harmonic at the 13th. (Lightly touch and lift off just after plucking it) it should be very close to the fretted 13th note.
This is actually the best way to get the intonation set at the bridge because it eliminates any nut discrepancies. Also remember that every straight fret system (including fender and Gibson's) they are all 'not perfect'. If you can get the guitar sounding good with a capo, then the problem is at the nut.
If this works good, then set the intonation for the thinnest string with the capo on fret 1. (Using the harmonic at fret 13 and the note at 13)
Measure the distance from this bridge position to the first fret (in mm) and divide it by 0.94387. This will give you the length your string should be. I.E. the leading edge of the nut.
All this is reverse maths. When I build a guitar I don't worry muh about scale length. I get it all together, mark where I want my nut to be, mark where I want my bridge to be and multiply that length by 0.9438743127 for each fret. As long as you clamp your measuring tape and double check, your good to go. When you understand this method it makes checking nut spacings and harmonics etc fall into place. You begin to understand what your doing to the wood based on the viration lengths of the strings.
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