Two-layer aluminium neck

Among the drawbacks of my old T-beam designs were the lack of a truss rod or similar system to control the bow of the neck.

A way to help this - but still use stock aluminium beam for the guitar - could be having a neck in two layers - an upper flat beam, tightening itself by pulling on a similar lower beam.

I hope the picture explains it, but in case it doesn't: The design uses a screw being retained by a bracket attached to the lower side of the top beam. The screw goes into a threaded hole in the end of the lower beam. When tightened, the screw will draw the top beam downwards, counteracting the pull of the strings.

With this build, I'll try if it works. The upper beam is only the length of the neck. It has frets mounted directly into it. The lower beam extends into a narrow body.

On the bridge end, I plan to mount a "stick-and-screw" tuner system. The prototype shown here works decently. I imagine, that using a brass bracket rather than the aluminium one here as well as harder steel for the screw threads will improve that.

The nut end contains a brass bar for holding the string ends, plus - on the bottom side - a bracket for the screw, that tightens the neck against the strings' pull.

Today, I cut the fret slots in a home made miter box and mounted the frets. The glue (two component epoxy) is hardening at the moment.  Tomorrow, I shall see how well it turned out.

Next steps will be making the brass bar and bracket for the nut end plus drilling the screw hole in the lower beam.