Recommended test
Open CAD → Tools → Fretboard designer, then verify the first complete calculation loop.
- Switch among Classical 650, Classical 660, and Steel 25.5 presets. Confirm all physical values and both previews update together.
- Choose Custom and change scale length, fret count, nut width, width at the 12th fret, board length, thickness, and fret-slot width.
- Switch Surface profile from Flat to Constant, enter a radius such as 406.4 mm, and confirm Crown at end and Minimum edge update.
- Choose Compound, enter 254 mm at the nut and 406.4 mm at the end, and confirm the reported radius and crown change continuously along the board. Then set End profile to Flat and confirm the end cross-section reports Flat · R ∞ with zero crown.
- Choose Soundhole end, enter an 85 mm soundhole and a 20 mm intersection depth, and confirm the plan and 3D blank receive the same concave circular end.
- Enable Linear fretboard slope, enter 1.0 mm, and confirm the complete width descends evenly from zero at the nut to 1.0 mm at the board end while the back remains flat.
- Enable Full length edge fallaway, choose Bass side or Treble side, and confirm the selected physical edge descends smoothly from zero at the nut to the entered drop at the board end. In Plan view, confirm the transparent red map is almost invisible at the start and deepest at the selected edge and board end.
- Click several fret lines in Plan view. Confirm the selected line highlights and reports separate Treble and Bass surface thickness at that fret. These values describe the uncut surface and must not subtract fret-slot depth.
- Switch the fallaway to From fret, enter fret 6, and confirm the top is unchanged before fret 6 and blends smoothly into the end drop afterward. Combine it with Constant and Compound radius.
- With a 650 mm scale, confirm fret 12 is exactly 325.000 mm from the nut.
- Confirm the nut and 12th-fret dimensions are visible in Plan view and that the sides taper continuously rather than changing width at the 12th fret.
- Open 3D and orbit close to the nut and end. Confirm the crown is smooth, the back stays flat, and every slot follows the curved top without floating above it.
- Make the board shorter than one or more requested fret positions. Confirm those frets are reported as omitted rather than drawn outside the blank.
- Switch to 3D and confirm the tapered prism uses the same length, widths, thickness, and fret-slot centre positions as the 2D plan.
- Enter an impossible or unsafe combination and confirm a clear validation message replaces broken geometry.
- Click Save and confirm a
.cadiv-fretboardfile is created. Change several values, click Open, and confirm the complete saved definition and both previews return. - Confirm the dirty dot appears after an edit and clears after Save. Also test Ctrl+S, Ctrl+Shift+S, and Ctrl+O.
- Click Insert into CAD. Choose a sketch plane if needed, click once where the nut centre should sit, and confirm one linked Fretboard object appears in Sketch and 3D.
- Select the linked object, choose Edit in Fretboard Designer, change a measurement, and use Update CAD. Confirm the same placed object rebuilds without losing its plane-local position or rotation.
- Open CAM → Operations → Add engraving, choose Fret slots, and click the linked fretboard. Test this with Flat, Constant, and Compound surface profiles.
- Confirm the 0.6 mm slot cutter is selected, set slot depth, stepdown, feed, plunge, and spindle, then create the operation.
- Leave Slot ends on Through and confirm each cutter centreline extends beyond both tapered edges by the cutter radius plus the entered Edge clearance. Change cutter diameter and confirm the extension updates.
- Switch Slot ends to Blind, enter a 2.0 mm shoulder, and confirm exactly 2.0 mm of physical wood remains at both ends. Enter an impossible shoulder and confirm creation is blocked.
- Leave Cutting order on By depth and confirm every fret is visited at the first stepdown before the next depth starts. Switch to Finish each fret and confirm one fret receives all depth passes before the cutter advances.
- Inspect every fret centreline in 2D, run Simulate and Material playback, review the estimated time, and verify the exported Shapeoko program uses the entered feed and plunge rates.
- On Constant and Compound boards, confirm each slot bends smoothly in Z across the local crown while remaining at the entered depth below the surface. On a flat board, confirm each slot remains constant Z.
- Try a cutter wider than the designed slot and a slot depth greater than the minimum edge thickness. Confirm both are blocked with a specific safety message.
- Choose Operations → Add contour, click the linked fretboard outline, and confirm Outside is the initial cutter placement while Inside remains available.
- Create the perimeter contour, inspect its compensation and tabs in 2D and Simulate, then edit the linked fretboard length or widths and confirm the contour rebuilds from the same object.
- Use Reset and confirm the default classical design returns.
01 · PHYSICAL BLANK
A small set of explicit measurements
The designer uses scale length, fret count, nut width, width at the 12th fret, total board length, thickness, and fret-slot width. It derives one continuous taper from those measurements and reports the calculated width at the end of the blank.
Presets are starting points rather than manufacturing recommendations. Every value remains editable in millimetres, Custom is selected automatically when a preset value is changed, and fret-slot width starts at 0.6 mm.
02 · FRET POSITIONS
Exact centreline locations
Fret n is positioned from the nut using scale × (1 - 2-n/12). The table reports both distance from the nut and the remaining distance to the nominal bridge location. The 12th fret is therefore exactly half the scale length.
The design now stores the intended slot width, defaulting to 0.6 mm, while each musical position remains one exact centreline. Cutter choice, slot depth, and fretwire remain later CAM decisions.
03 · BOARD END
Straight or fitted to a circular soundhole
Straight retains the normal tapered end. Soundhole end uses the entered soundhole diameter and intersection depth to trim the board with an exact concave circular boundary. The designer blocks a cutout that reaches a requested fret slot, and reports the remaining clearance to the last visible fret.
The trimmed outline is not presentation artwork. The same boundary is embedded in CAD, exported as linework, offered to Contour CAM, and respected by fretboard surfacing.
04 · SURFACE PROFILE
Three independent layers on one physical surface
Flat keeps the symmetric crown at zero. Constant radius uses one circular radius for the whole board. Compound radius accepts an independent Radius or Flat state at both the nut and board end. Two numeric radii retain the established linear-radius blend. When either endpoint is Flat, Cadivari stores true zero curvature (R ∞) and blends curvature smoothly toward it instead of substituting an arbitrary huge radius. All modes retain a perfectly flat back and treat the entered thickness as the nut centre datum.
Fretboard slope is a separate width-uniform plane: Linear blends from zero at the nut to the entered end drop across the entire board width. It describes the subtle longitudinal slope of the fretboard, not string relief.
Edge fallaway is the asymmetric layer. Full length blends linearly from zero at the nut to the entered drop at the selected physical Bass or Treble side. In plan view, Bass is the lower displayed edge and Treble is the upper displayed edge. From fret preserves the original surface up to the selected fret and then uses a smooth transition. The plan's clipped red heat map shows only this asymmetric removal: faint at the start and strongest at the selected edge and end. Radius, slope, and fallaway can be combined without changing the flat back.
Validation samples the complete combined surface and blocks configurations that leave less than 0.5 mm at an edge. Calculated results report nut centre, end centre, Bass end, Treble end, and minimum edge thickness.
05 · COORDINATED PREVIEW
One model in plan and true 3D
Plan view emphasizes the live end boundary, tapered outline, nut, fret positions, octave marker, key millimetre dimensions, and the optional edge-fallaway heat map. Each fret line is selectable: clicking one highlights the station and reports its uncut Treble- and Bass-edge surface thickness without subtracting slot depth.
Measured cross-section insets compare the nut and board end with one shared horizontal and vertical scale, preserving the true physical proportions of each crown. Their solid profiles use the exact combined surface, the dashed line is the crown tangent, and Treble/Bass labels report the real edge drop. Very large classical radii therefore appear honestly close to flat rather than visually exaggerated.
The 3D view builds the actual solid with the selected soundhole cutout, symmetric radius, uniform slope, and asymmetric fallaway on a flat back. Exact-width fret-slot ribbons conform to the combined surface rather than floating as straight display lines.
06 · PROJECT FILE
One portable fretboard definition
Save writes a versioned .cadiv-fretboard document containing every editable millimetre value. Version 5 stores the independent fretboard-slope definition; versions 1–4 migrate automatically with slope safely off while preserving their modeled geometry. Desktop builds retain the selected path for later saves, while browser builds download the same portable JSON file.
The standalone file can be shared independently. Inserting it into CAD embeds the complete measured definition in the main .cadiv project, so the placed component continues to rebuild even if the external source file is moved.
07 · LINKED CAD OBJECT
Place once and rebuild associatively
Insert into CAD returns to the main workspace. If no sketch is active, Cadivari first asks for a visible reference plane or planar face. The next canvas click places the nut centre; the board extends along its local positive X direction. Escape cancels before placement.
Sketch shows one selectable component with its exact straight or soundhole-trimmed outline, nut, and every visible equal-temperament fret-slot centreline. 3D uses the same embedded definition to render its radius and bass fallaway. Position and angle remain editable without exploding the component.
Select the object and choose Edit in Fretboard Designer to reopen the embedded measurements. Update CAD rebuilds that same object and retains its project identity, placement, and rotation. SVG and PDF drawing exports include the outline, nut, and fret centrelines.
08 · FRETBOARD CAM
One physical model across fretboard operations
With Stock sizing set to Auto, opening CAM measures the complete rotated fretboard blank and applies the current equal fit margin on all four sides.
For the perimeter, choose Add contour and click the linked outline. A soundhole end remains the exact concave circular boundary rather than reverting to a straight blank. The standard compensation, ramp, depth, tabs, start point, animation, G-code, and export controls remain in use.
For slots, choose Add engraving → Fret slots. Every slot follows the combined radius, width-uniform slope, and selected edge fallaway while staying at constant local depth. By depth and Finish each fret ordering, Through and Blind ends, edge clearance, cutter-width checks, and minimum-edge-thickness checks continue to apply.
For surface finishing, choose Surface fretboard with a ball nose. Along and Across raster paths follow the same combined surface. With a soundhole end, Cadivari clips the raster using the real cutter radius, splitting or shortening lanes so the cutter does not cross the opening.
Set stock-top Z0 at the highest modeled crown. Exported Z follows the circular crown, linear fretboard slope, and selected physical-edge fallaway. Verify the datum, tool, stock, fixtures, and real surface before machining.
CURRENT BOUNDARY
A reliable classical-surface milestone
The designer now supports straight and circular soundhole ends, flat through near-flat compound radius, uniform fretboard slope, full-length or from-fret Bass/Treble fallaway, linked CAD and 3D, associative contouring, surface-following slots, and cutter-safe ball-nose surfacing.
Arbitrary decorative end shapes, multiple relief control stations, fretwire libraries, roughing/rest machining, and general freeform 3D fretboard surfaces remain later iterations.