A better calibration print

thingiverse

I'm fed up with calibration cubes. Twenty millimeters is woefully inadequate to detect any real inaccuracies in 3D printers, and at such minuscule sizes, filament contraction significantly contributes to any error you might find. 3D printers naturally have protruding corners where the nozzle's dwell time overextrudes plastic. The bottom layer is usually squished down a bit, while top layers tend to jut out slightly as well, resulting in surfaces that are impossible to measure. This calibration plate offers several advantages: Rounded corners provide a smooth surface for measuring with calipers. Inner diameters allow you to measure filament contraction and the notorious ID filament drag. Create an Excel sheet with your measured percent errors to make perfect IDs! Vertical bores are small, so you won't need supports. A large footprint provides a stable test bed for leveling and precision. Easily measure skew!