Neck angle

[Pat.Hawkins]

Sorry - bad pun.... but I'm hoping someone can put me straight (another pun) on the topic of necks.

It seems the more I read and see, the confuseder I become

Here's what I believe is the basics:

1Steel string acoustics have a back-leaning angle to counteract string tension;
2Steel string acoustics have a truss rod to create an up-bow to allow for string vibration;
3Classical guitars don't need a truss rod or any type of reinforcing;
4Classical guitars are built with an up-leaning angle to allow for string vibration;
5Ukulele necks don't need a truss rod or reinforcing; and
6Ukulele necks all have straight (0 degrees) neck angles

Sorry for such a basic query but there's so much information out there.......
Cheers

[kiwigeo]

1Steel string acoustics have a back-leaning angle to counteract string tension;
2Steel string acoustics have a truss rod to create an up-bow to allow for string vibration;
3Classical guitars don't need a truss rod or any type of reinforcing;
4Classical guitars are built with an up-leaning angle to allow for string vibration;
5Ukulele necks don't need a truss rod or reinforcing; and
6Ukulele necks all have straight (0 degrees) neck angles

Sorry for such a basic query but there's so much information out there.......
Cheers

My take on your questions:
1.) Steel string acoustics have a negative neck rake to counteract string tension.
2.) Steel string acoustics have a truss rod to control neck relief which is to minimize strings hitting frets mid scale. (think of the rotating skipping rope as an analogy).
3.) Classical guitars traditionally don't have a truss rod or neck reinforcing. I tend to put one in mainly for reinforcement but I find it also increases sustain.
4.) Classical guitars have a positive neck rake. This is to create neck relief to minimize string buzz. Some makers put in a shallow scoop on the bass side mid fret area of the fret board for added relief under the bass strings.
5.) Uke necks traditionally don't have a truss rod or reinforcing. Not sure what Allen does but some makers put in reinforcing of some sort (cf rod/bar etc).
6.) The last uke I built had a slight positive neck rake but not as much as I'd use on a classical.
7.) As a note of interest Lutes get around the issue of neck relief in two ways. The soundboard is dished and the tie around gut frets decrease in gauge up the neck.

[Trevor Gore]

My version:

Steel string acoustics have a back leaning angle so that the normal string height above the soundboard at the saddle (~13mm) and the normal action at fret 12 (E2.8mm, e 1.8mm) can be achieved. The variable that should be used to achieve these figures is the neck angle and typically results in a back leaning neck

Steel string acoustics have (adjustable) truss rods so that neck relief can be adjusted for best playability (for that player) and so that long-term creep (neck pulling forward) can be controlled. When they don’t have a truss rod, too much relief is almost inevitable

Classical guitars have truss rods for the same reason as steel string guitars. Classical guitars that don’t have them are missing out on continued long-term playability and stability. Classical guitars get away with not having truss rods because the action is so much higher than steel string guitars and so disguises relief problems and otherwise poor playability. A well set-up classical (e.g. with a truss rod) can play rattle-free with the action about 0.5mm lower than a typical classical for the same pluck strength

Classical guitars are built with an up-leaning neck angle so that the normal string height above the soundboard at the saddle (~10-11mm) and the normal action (E 4.0 mm, e 3.0 mm) can be achieved. The variable that should be used to achieve these figures is the neck angle and typically results in a forward leaning neck

Someone expert in ukes will no doubt contribute their thoughts on ukes, but I would imagine that the thinking runs along similar lines.

[kiwigeo]

Trevor Gore...the Neck Angel

[Dave M]

And one might add that getting this geometry right is a pretty subtle process and remains one of the more difficult tasks for we beginners.

[ozziebluesman]

Hi Martin,
Do you build with a Spanish Heel and also install a truss rod?
If yes could you point me in the direction of some reading fodder please?
Cheers
Alan

[kiwigeo]

Hi Alan,

My first build was an OM steel string built with a Spanish heel and truss rod. The build was basically as per Jim William's book "A Guitar Maker's Manual".

https://www.amazon.com.au/Guitar-Makers ... 0958907501

Hi Martin,
Do you build with a Spanish Heel and also install a truss rod?
If yes could you point me in the direction of some reading fodder please?
Cheers
Alan

[ozziebluesman]

Thanks Martin.

[kiwigeo]

Jim William's uses a workboard and basically builds a steel string the same way you'd do a classical using the Spanish method....

Thanks Martin.

[ozziebluesman]

Ok Martin that's the advice I'm looking for. I have enough information to build a Torres inspired smaller Classical but I would like to use a truss rod and build traditionally on a solera. I have just found my Xmas present the Jim Williams Book.
Thank you
Cheers
Alan

[kiwigeo]

Jim's book is an interesting work. Some would argue that it's a bit dated but it's what got me started...the book is basically what Paddy Burgin and Dave Freeman base their building course on in NZ.

Ok Martin that's the advice I'm looking for. I have enough information to build a Torres inspired smaller Classical but I would like to use a truss rod and build traditionally on a solera. I have just found my Xmas present the Jim Williams Book.
Thank you
Cheers
Alan

[ozziebluesman]

Look forward to the read I managed to buy a secondhand copy.
Thanks again for the heads up.
Paddy Burgin is a great builder. He got me into weissenborn instruments.
Cheers
Al