Neck Angle Planner

What this tool is for

Model neck-plane projection to a measured bridge height without authorizing structural cutting. Geometry tools apply explicit models to named measurements. A coordinate or angle must still be checked against a physical drawing, real hardware, tolerances, and material behavior.

Use it when you can describe the current state and need a defensible next check. It is not a shortcut around inspection: preserve the starting state, change one variable, and verify the result under the same conditions.

Before you begin

Establish body plane, scale-direction projection run, bridge string height, fretboard and fret height, desired action, and pocket depth from one coherent side-view datum.

• Use a stable, tuned instrument unless the page specifically investigates tuning.
• Name the physical reference, unit, and test condition beside every important number.
• Keep the original measurements so any reversible change can be returned to baseline.

Input guide

Scale length (selected unit)

sets the interpretation and display unit; do not mix units elsewhere in the same run.

Body-plane reference offset

provides a measured or counted input; confirm the allowed range and repeat the reading before relying on it.

String height at bridge

supplies a measured geometric quantity whose datum and resolution should be written down.

Fretboard thickness

provides a measured or counted input; confirm the allowed range and repeat the reading before relying on it.

Fret height

supplies a measured geometric quantity whose datum and resolution should be written down.

Desired action

supplies a measured geometric quantity whose datum and resolution should be written down.

Neck pocket depth

provides a measured or counted input; confirm the allowed range and repeat the reading before relying on it.

Neck projection distance

supplies a measured geometric quantity whose datum and resolution should be written down.

Input and display unit

sets the interpretation and display unit; do not mix units elsewhere in the same run.

Input labels describe evidence, not targets. A placeholder demonstrates format only; it is never a recommendation for a particular guitar.

How the result should be read

Use the result to compare bridge, pocket, fretboard, and action assumptions. A sign reversal or unexpectedly large angle usually indicates mixed datums.

Read priorities from top to bottom, but stop as soon as new evidence contradicts an earlier assumption. Save or print the result ticket with the entered conditions so another person can reproduce the decision.

Method and logic

The model subtracts the neck-plane stack from the required bridge string line, then uses atan(rise/run) for a small-angle projection. Values are geometric, not construction tolerances.

The page keeps calculation and diagnostic claims deliberately bounded. Display rounding improves readability, while the underlying logic uses entered values; descriptive branches report relative tendencies and the evidence needed to confirm them.

Worked example

If the required rise over a 600 mm run is 10 mm, the geometric angle is about atan(10/600)=0.955 degrees. Recheck every stack component before treating that as a design candidate.

The example demonstrates reasoning, not a universal setup specification. Substitute real measurements and repeat the final test before accepting the next action.

Assumptions and limitations

Top carve, neck flex, bridge adjustment range, compression, fretwork, finish, and joint structure are omitted. The tool never authorizes routing a pocket or altering a set neck.

Instrument design, service history, measurement error, and player technique can outweigh a calculator or checklist. Where manufacturer instructions exist for the exact hardware, use those instructions and record the revision consulted.

Safety and stop conditions

Stop for abnormal resistance, cracking, heat, odor, electrical sensation, moving wood or joints, a measurement that cannot be repeated, or any step that would remove material without a confirmed cause. Secure strings and stored mechanical energy before hardware work. Refer structural, fret-cutting, mains-powered, or uncertain repairs to a qualified technician.

Related workflow

• Shim Thickness Planner — Compare tapered thickness differences for a full pocket and an entered shorter shim length.
• High Action Diagnostic Tool — Separate relief, bridge, nut, and neck-angle clues before adjustment.
• Geometry Measurement Definitions — Name every datum before entering a number.

Open the related page that answers the next unresolved question; do not run every tool as if every system needs adjustment.