LeftyBassist.com

In another thread I detail the steps on how to build a neck from rough materials, but in that thread I didn't cover the steps on how to design a neck so I'll do it here

A couple of things must be determined up front, and will serve as the skeleton of the neck design:

* scale length
* number of strings
* nut width
* bridge spacing
* number of frets
* neck type
* headstock type

In the case of this neck design, it will be a 5-string 34"-scale 21-fret bolt-on with a 1-7/8" nut and 19mm bridge spacing. It will also have a Fender style flat headstock with 4+1 tuning configuration.

I start out in a CAD package and draw the centerline for the assembled bass. I mark off one end that represent the theoretical neutral point on the bridge, and a distance equal to the scale another line is placed parallel. With this I now have a reference backbone to design from.

I add additional references at the bridge end that define the centerline of each string where it intersects the scale length line. I trim the line at the opposite end to the width of the nut, being certain to center the length equally about the neck centerline. I add a line outside of the two outer strings that represents the outer string diameter and an added amount to provide space on each outer edge of the fretboard. Next it's time to locate the strings thru the nut reference, and then align the tuner holes so that the strings will pull straight away from the nut.

Once this is done I block out the headstock, and leave room on the bottom so I can utilize one template to make many differing headstock designs. For reference I generate a few solids and apply a material to them so I get my first look at the conceptual design. Here's the first look at the newly designed 5-string neck




more to come on making the template in a follow-up post ...

all the best,

R

I will next print a few key areas of the design and trasnfer them to a MDF board so I can cut an initial routing template. This template will serve as the guidance for my first prototype construction of the new design. In this image you can see the detailed headstock and heel are accurately located in place so I can trace their curves. For everything with a straight line, I bring out a straight edge and connect the dots



Now it's time to cut the template out and carefully sand the contours smooth. Everything must be right to the line, but leaving a few thousandths of an inch for fine tuning the fit to the body after the neck is made.

If everything looks and works well, I'll make a more permanent template from 3/4" voidless Birch plywood. In the neck build thread I am utilizing a Birch plywood template I had built for a previous project.

One oddity to note - this template can be used to construct both righty and lefty necks. This activity is "hand neutral"

all the best,

R

here's another CAD image showing the headstock detail progress, plus the trussrod channel and adjustment nut tunnel in the heel (the fretboard is not shown in this image so you can see these internal details)



and what it would look like for a model that contains pulltruded carbon fiber stiffening bars




when the day comes that I have a 3-axis CNC system in the shop, I'll evolve these models to contain the detailed rear profile as well. I can then run the model out thru a translator and into a CNC control code package (overly simplified for those who work with real CNC operations)

CNC truly is my target goal for the future. adding this to the shop would allow me the accuracy and speed of the big boyz, the ease of flipping any instrument model lefty/righty, and the ability to customize pickup and pickguard details on the fly. even with a CNC system there is still a TON of hand detailing to do before a body/neck is ready for finishing

but for now it's MDF, plywood templates, and hand routing

all the best,

R