This guitar neckuses Carbon fiber as an exoskeleton with a lightweight wood core, such aswillow or basswood as a compression medium for the core. The finalouter face of the neck is a thin 1/32” veneer of hard wood. Therecan be as much as 200 pounds of pull on a guitar neck.

I've attached my design

Myquestion is do I have the design right? Where can it be improved?

Only one point:  You will need at least some of the CF reinforcement to run straight through the neck, on the bottom side also, where you have tour "t-piece" for the guitar body
The strings on the top will try to stretch the underside of the neck and compress the upper side. The upper side with the fretboard, is already much stronger than the underside.

I would certainly use at least a few layers of unidirectional CF going all the way through on the underside of the neck.

The stiffer the neck is, the longer the sustain is and it will also produce a "dryer" sound.

"Sapere Aude"... Dare to KNOW!

The written word is the only truly efficient vehicle for transmitting a complex concept from mind to mind...

103% of all people do not understand statistics...

Do not adjust our mind, theres a fault in reality :-)

I'm also using a 1 1/8” carbon fiber square tube as the neck post.

This is the fiber that I am using with the West system epoxy.

Thanks a bunch.

This dry twill cloth uses AksaA-42 12k carbon fiber (click link for technical data)and is often used in aerospace and automotive applications. Thisparticular woven fabric is the thickest we offer and is usedcommonly as a very efficient and affordable means for building upthickness in parts. A single ply of this material is roughlyequivalent to using 3 plies of the lighter weight twill (part# 13005-D) and as such may be a perfect alternative to yourproject.

Fiber Properties - Non Composite 100% fibervolume

• Tensile Strength -   512 ksi / 3,530 MPa    

     

• Tensile Modulus -   33.4 Msi / 230 GPa    

     
• Density - 0.064 lbs/in^3 / 1.76 g/cm^3    
  
  

Fiber Properties - Composite normalized to60% fiber volume with Toray 250F resin

• Tensile Strength -   270 ksi / 1,860 MPa    

     
• Tensile Modulus - 20.0 Msi / 135 GPa
  
  

Howwould oven curing affect the stability of this layup?

Myultimate goal is to build a light weight neck, that stable enoughthat a truss rod is unnecessary.

I just commented on your 3D drawing, it does not seem to show a layer(s) of CF going through the "neck post" along the bottom/underside of the neck ..  You WILL need that to counteract the tension on the underside of the neck.

An open ended CF square box has very little compressive strength perpendicular to the box.  The same goes for expansion forces..

"Sapere Aude"... Dare to KNOW!

The written word is the only truly efficient vehicle for transmitting a complex concept from mind to mind...

103% of all people do not understand statistics...

Do not adjust our mind, theres a fault in reality :-)

Here is a new drawing.

The green post is 1/16” wall thickness x 1 1/8”carbon fiber tube.

Again a wood core,

now with 3 layers of carbon fiber onthe bottom of neck profile

bending down into the post and bondingat front and back of post.

3 more layers bridging over the top ofpost.

Excactly!  That is precisely what I meant ..  

I'm looking forward to seeing pictures from the actual construction fo this guitar neck!

Good Luck!

"Sapere Aude"... Dare to KNOW!

The written word is the only truly efficient vehicle for transmitting a complex concept from mind to mind...

103% of all people do not understand statistics...

Do not adjust our mind, theres a fault in reality :-)

Thanks, Dravis

I intend to start soon.

First I'll shape the Willow core and heat bend the outer wood veneer.

I'll bend several veneers while I'm at it.

Then rout the willow core down allowing for the 3 outer layers of carbon fiber.

And then further route out for the 3 capping layers of carbon fiber,which are the first layup.

Then come the 3 outer layers of carbon that also bond into the carbon tube.

I've seen where other builders after the room temperature cure, string up their neck under tension

and place it in the sun for a month. I'm trying to understand this practice??

I think stringing it up and leaving it in the sun for a month, probably just goes for pure wood necks.. that way, if it stays straight and does not twist or bend, it is totally stable, and will outlast the rest of the instrument
With Epoxy and CF "casing" it will not warp, but it will be damaged by the UV light from the sun ...  I have an experimental prototype gun-stock with a balsa core and 2 layers of 200gsm CF cover, that has sat in tension holding up a main ceiling cross-beam for over 10 years ... it has not deformed measurably ...   It takes more than 300 kg 's of force to lift the beam even 2 mm ... But it never sees any sunlight ...

"Sapere Aude"... Dare to KNOW!

The written word is the only truly efficient vehicle for transmitting a complex concept from mind to mind...

103% of all people do not understand statistics...

Do not adjust our mind, theres a fault in reality :-)

I would also like to see pics of how you do this. I was actually just talking to a buddy of mine the other day about cf neck design. wondering about truss rods and if you would need them still.