De Westermolen, Kollumerpomp of the upright shaft. At the bottom of the upright shaft is the "crown wheel", which has 41 cogs, drives a gearwheel with 42 cogs on the axle of the Archimedes' screw. The axle of the Archimedes' screw is diameter. The screw is diameter . It is inclined at 16.7°. Each revolution of the screw lifts of water. The Archimedes' screw that pumped water into the polder has been removed. "De Westermolen" is open on Friday mornings. It is also open on Saturday mornings if there is enough wind to work the mill. De Westermolen, Kollumerpomp De Westermolen is a
Archimedes (CAD) Archimedes (CAD) Archimedes – "The Open CAD" – (also called Arquimedes) is a computer-aided design (CAD) program being developed with direct input from architects and architecture firms. With this design philosophy, the developers hope to create software better suited for architecture than the currently widely used AutoCAD, and other available CAD software. The program is free software released under the Eclipse Public License. Archimedes uses its own XML-based open format, which resembles SVG. It does not yet include support for other , but DXF support is planned. Archimedes is written in Java, and the latest version runs on Windows, Mac