Choose a ring piece, track, and wheel size from the controls.
Pick an Ink colour and Pen width, then drag a wheel hole to draw curves.
Use pinch-to-zoom on touch, mouse wheel to zoom on desktop, and drag empty space to pan.
Hide Gear toggles ring and wheel visibility so you can present the clean trace.
Reset View recentres and refits the current diagram.
Exporting
Export PNG saves the current diagram as a tightly cropped PNG. On touch devices it uses native sharing when available; on desktop it downloads the file.