<_name>The Spiral of Archimedes fablabchemnitz.de.archimedesspiral R = r + aθ 50 3 50 Left Right 0 5 Notes The option "turns" only works if you set "length (mm)" to 0.0. Otherwise the length value will be used to calculate the spiral for given length. The higher the "step" value is set the better the accuracy is. If you set the step value really low the resulting length will not be precise and the curve is maybe not drawn at all. You can validate the length by using the extension "Visualize Path > Measure Path" all