Turmwindmühlen, an early export hit from Holland
The ground plan of our small windmill is octagonal. This shape is easy to rip onto the plywood sheets even for non-mathematicians, because you basically just need to draw two right-angled crosses, which are twisted by 45°. Everything, what you need to do except tape measure, need a pencil and a marking square, is therefore a simple triangle. The octagonal shape has another advantage: You can cut all joints of the vertical walls and the strips to an exact 22.5° miter, because this angle can be found as an adjustment notch on every miter box and table saw.
The construction of the mill hood is a little more difficult. The perpendicular bisector is not a simple geometric shape, but an area of trapezium and semicircle, which you freehand or after 1:1-be able to tear open the template of our construction plan. Important: The axle plate, holding the impeller, is inclined by about 5° and is held by a bar that is also inclined at the lower end. The bicycle hub is fixed to this plate with three screws and must be able to rotate freely and smoothly. I wish you success!
4 Die acht Seitenwände des Mühlenkorpus schneiden Sie aus Flugzeugsperrholz nach Schablone aus.
5 Mit kleinen Nägeln fixieren Sie die Seitenwände auf den beiden kleinen Achtecken. Nail the top octagon flush with the top edge, nail the second halfway up the side panels.
6 Auf der kleinen Tischkreissäge schneiden Sie alle Quadratleisten, that you need for the straight outer walls and for the balcony parapet.
7 Die geraden Seitenwände sind an ihren Seiten auf 22,5°-Gehrung geschnitten. Glue the square strips to these sides, but only on four of eight side walls.
8 Um die achteckige Bodenplatte herum verleimen und nageln Sie die geraden Seitenwände, alternately one with and one without strips.
9 Die Mühlenhaube beherbergt die Fahrradnabe, over which the wing cross rotates. It consists of the base plate, three perpendicular bisectors and the axle plate, which carries the hub and the mill wheel.
10 Die Haube schieben Sie mit dem mittig eingeklebten 8-mm-Alurohr in das durchlaufende 10-mm-Alurohr des Korpus.