A browser tool for laser-cut kerf bending (living hinge) patterns, made for cylinders and pendant lampshades. Everything is metric and runs in a single HTML file – no install, no build step, nothing is uploaded.
Live: https://sonarkon.github.io/Kerf-O-Matic-9000/
Contents
Quick start
- Enter the width (= circumference) and height of the board – or the diameter you want, and the width is calculated.
- Choose the material and its thickness, then a shape and the slot values.
- Check the bendability on the right and the preview (try 3D and the lamp button).
- Cut a few strips in Test Pattern mode to find the right values for your material.
- Save SVG and cut. For a lamp, switch to Lamp and save the complete cut set.
Every section has a ↺ button that resets just that section to its defaults (for example only the lamp settings); Reset settings at the bottom resets everything.
Modes
| Mode | What it is for |
|---|
| Simple | One even pattern across the board. |
| Creative | Bands and modulators for lampshade designs on the same slot grid. |
| Test Pattern | A set of labelled test strips that vary one value. |
| Lamp | The parts for a pendant lamp (E27) around the Simple/Creative shade. |
Simple
- Shapes: pill (one closed path with true arcs), dogbone (round relief holes at the slot ends), S-slot (constant width, exact arcs), line, meander, ellipse, rectangle, diamond, hexagon, chevron, cross.
- Slots: length, width, vertical and horizontal gap.
- Vertical offset: top-aligned, centered (top and bottom edges mirror each other) or a custom value.
Creative
Everything from Simple, plus per-slot variation on the same grid, so the shade still bends evenly:
- Bands – horizontal zones from top to bottom, each with its own shape and optional slot size (mix pill, dogbone, S-slot …).
- Modulators – a source drives a slot property:
- sources: linear gradient (any angle, optionally mirrored), radial, waves, noise, or a greyscale image;
- targets: slot width, slot length, vertical shift (moves each slot up or down – with noise the bridges get an irregular, organic rhythm; slots in a column always keep the minimum gap), remove slots, swap the shape;
- they stack from top to bottom with adjustable strength.
- Drag a band or modulator by its header to reorder it (or use ↑ / ↓); click the header to collapse or expand it.
- ⧉ duplicates a band or modulator; the checkbox in a modulator's header switches it off for a moment without deleting it.
- With Seamless on, radial, waves and noise wrap around the cylinder, so the design continues across the glue seam.
- Image source:
- Stretch, Fit (no distortion), Fill (cropped) or Tile (whole tiles around the cylinder with Seamless); outside a fitted image the modulator has no effect.
- A preview in the board's proportions shows the image as it reaches the pattern (levels, blur, invert) – drag it to move it, use the wheel or the Size slider to scale it.
- Levels: a histogram of the image with markers for black point, mid-tones (gamma) and white point – drag them to spread a flat photo over the full range; double-click resets.
- Blur (mm) smooths out single pixels.
- Strength, threshold, angle, phase and the radial centre are sliders with their value next to them.
- An image is stored (downscaled) with the design, so it reloads completely.
Test Pattern
- Strips that vary one value (horizontal gap, slot length, vertical gap or slot width) from From to To; Count can also be 1.
- Each strip is engraved with the varied value, all slot values (
Pill L 20 W 2 Gap V 4 H 2) and the project name – lines shrink to fit, and wrap on short strips.
- The panel lists the smallest inner diameter per strip that should stay within the material's “good” range.
Lamp
Parts for a pendant lamp with an E27 socket around the shade from Simple or Creative (whichever was used last):
This is the beginning of the README. Read the rest at the original. Read the full README ↗
