3D TOOL

Neck Relief & Action Simulator

Adjust the truss rod and the bridge and watch the action change.

Drag to rotate · scroll to zoom · work through the four steps in order

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Static reference

The static reference carries the same figures and the same steps as the 3D model. Nothing is lost except the ability to rotate it.

Setup steps

Neck and strings

Instrument

String set

Tuning

Truss rod tension55%

Saddle height0.16 in

Nut height0.014 in

Scale length25.5 in

Readout

Relief

Relief in inches

Target relief

Truss rod

Action at the 12th

Nut height

Saddle height

Saddle change

String load

Relief—

Action at 12—

Action at the 12th

Relief is the forward bow deliberately left in the neck so the strings clear the frets through the middle of the board. A neck set dead straight buzzes. The bow is exaggerated in the model — a quarter of a millimetre on a 25 in neck is invisible at true scale — so the figures in the panel are the ones to read, not the picture.

How to use it

Drag to rotate; scroll to zoom.
Move the truss rod slider and watch the neck bend.
Raise and lower the bridge and the nut.
Change the string gauge and the tuning.
Step through the setup sequence in order.
Export the adjustment record.

What it reports

Neck relief in millimetres at the seventh fret
Action at every fret in millimetres
The truss rod adjustment needed to reach target relief
The bridge and nut heights that follow
A downloadable adjustment record

Relief and action are two different adjustments and they interact. Relief is set first, at the seventh fret, and action is measured at the twelfth.

What this model doesA neck you can bend with a truss rod, strung with strings you can change, over a bridge and nut you can raise and lower. The action at every fret is computed live and shown in millimetres, with a warning when the geometry is wrong.

Safety

These models are teaching simulations. They are not a measurement of your instrument and they are not a substitute for the manufacturer’s specifications.
Fret wire ends are sharp. Wear eye protection when you cut, file and crown frets, and sweep the bench rather than blowing the offcuts away.
Wood dust from rosewood, ebony, mahogany and cedar is a respiratory sensitiser. Use extraction or a P2/P100 respirator when you sand or rout.
A strung instrument stores real energy. Bring strings up to pitch gradually and never put your face over a neck while you tune it up for the first time.

Educational model. Figures are approximations produced by a simplified physical model. Verify against your own instrument before acting on anything shown here.

The other models

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Fret Placement Simulator

Place the frets for a scale length and read the intonation error in cents.

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Change the bracing and watch the top stiffness and voice change.

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Setup Wizard

A guided setup, one adjustment at a time, on a 3D guitar.

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