There are pretty little humidifiers for sale everywhere this Christmas. These widgets are the size of a mug of coffee and may also have pretty LED lights and magical salt crystals. They look very nice, but may be hard to get to work. The little mcgafter has an ultrasonic transducer at the top, which cavitates the water and turns it into cold steam. The transducer is kept wet with a long cotton wick. The wick is supposed to float in a little tube and lightly press against the underside of the transducer, keeping it wet. However, the wick tends to stick to the tube and not rise up sufficiently to wet the transducer and then there is no steam and no magic released from the crystals, which can all be very disappointing. My simple solution was to drop a little spring from an old ballpoint pen into the bottom of the tube to press the wick up - about half a spring is sufficient. A little piece of styrofoam placed into the tube to help the wick float ma...
RC Foamie Vulcan Bomber It is reasonably easy and low cost to make a RC plane from Styrofoam. Foam costs almost nothing - about Euro 2.50 for a block of 5x50x150 cm - and it is available in various thicknesses, 5, 8, 10 and 20 cm being common. I am building a delta wing plane that resembles an Avro Vulcan bomber, with a 1.3 m wingspan, and a Ducted Fan Engine inside the fuselage. From a safety point of view, nothing beats a foamy with a fully enclosed motor. There are two kinds of styrofoam, Expanded Polystyrene (the stuff used for exterior insulation of a home) and Extruded Polystyrene (More smooth and easier to sand, but heavier and used for roof insulation). Both kinds will cut super smooth with a hot wire and it is the same plastic, so you can just as well use the cheaper and lighter white beady stuff, since if you tune your cutter temperature properly, then you don't need to use sand paper. For reference, Polystyrene melts somewhere ...