I'm doing some planning for my CBG. Using a 25.5" fingerboard and using a length to the 21st fet give me a lengt out of the box of 17 59/64"or 455,14 mm. Now to compenstae the string tension some writers told me to give a negative relief of the neck about app. 1 degree.
Now comes the big question: this wil give me a negative of 455,14 x Tg 1 degree = 7,94 mm or app 5/16". I think this is a lot.
Also if I want to maintain a space between the lid and the neck inside the box, this means that I have to take a lot off the neck.
Or am I making a big mistake now? Ans shopuld I keep my neck just horizontal? I'm using red oak 3/4"thick for the neck with 3 strings.
Replies
Hi Honsik,
It is easiest to think of it as - if you have a design with a high bridge you need to have a neck to body angle to bring the strings down to a playable level. Electric guitars like a Strat have such a low bridge that no angle is needed but a Les Paul has a much higher tune-o-matic bridge and so the neck is angled.
Look at the bottom of this link which explains it better with diagrams.http://www.tundraman.com/Guitars/NeckAngle/index.php
Regards,
David
Having a neck angle will allow the strings to be closer to the fretboard/neck of the guitar. It does also help lower string tension and help make the guitar easier to play.
When you're saying 5/16" I assume you're using a neck through design and cutting 5/16" off the neck board (at the tail end) to make the neck angle. This is about right. There is a builder (can't remember her name right now) who uses 3/8". I tried this and it works great.
With maintaining the space inside the box, yes, you're cutting a lot off the neck and making it thinner. You may want to consider adding another board to the bottom of the neck inside the box and extending it out the tail end.
Some people also extend this board out the front end. It ends up looking like a dovetail joint on a regular guitar. You may need to do this if you're adding a pickup to the CBG and are cutting away the neck to allow room for the pickup.
I'm just curious, how would angling the neck lower the string tension, if the scale length is the same it should take the same amount of tension to bring it up to the note you want wouldn't it. Getting the action lower (by angling the neck) will make it easier to play by taking less pressure to push the string down because it is closer to the fretboard.
I think he is probably referring to the angle of the neck to the body, like CBJ suggested. When he says 'string tension", I suspect he is referring to the bowing effect that can happen when you tighten the strings up, resulting in higher string height near the body. I think I read somewhere that 2 degrees is a good starting point.
So couls you explain what's the purpose and benefit of giving the neck an angle of 1 or 2 degrees? Is it only to give a higher bridge?
If you're thinking or reading that some of us angle the neck back from the plane of the box (lid/back) then that's different and has no intended effect on string tension. Tho it could, that's not normally why we do this. CBJohn is right in that the tilt has nothing to do with relief.
Now, if you want to compensate for string tension (which in my opinion is absolutely unnecessary) you can add or subtract bow in the neck (mostly I do that on the fingerboard/fretboard) but then again, is up to you. If you find that your necks are causing string buzz (fretted, not likely to be an issue with fretless slide), then you might [read: might] want to consider creating a slight dip in the fingerboard of about .5mm between the two ends. I have done that on some builds and it works great. If you find that when you put heavier strings (see CBJohn's comments) then you will have more tension and thus might want to create a back-bow effect.
Angling the neck back in my experience allows the bridge/saddle to be a little higher.
-WY
I'm not sure what you are referring to. Relief refers to the amount of bow in the neck to help prevent string buzzing, and usually measured in thousands of an inch or fractions of a millimetre. The 1 degree might refer to a neck angle, where the neck is tilted back relative to the body, but this is nothing to do with relief - there's some incorrect and confusing terminology going on here.
Compensation refers to angling the bridge slightly to help correct the fact that when you fret the guitar it pulls the strings slightly sharp, and this is more pronounced on the lower-pitched heavier strings, hence the typical angled bridge saddles you see on acoustic guitars and the adjustable saddles on electrics.