Small, high-reving, brushless geared motors were used in 1926 already - alas only in the Göttingen wind tunnel (see also The Gallery). It should take a long time until those were finally fit to fly aboard a model airplane.
Our F5B planes are powered by brushless Kontronik and MEB electric motors. While information about Kontronik motors and speed controllers is available directly from Kontronik (phone +49-7457-94350, fax +49-7457-943590, Kontronik website), we'd like to show a few pictures of the motors we develop and build in cooperation with MEB (Edwin Bloch, phone +49-7457-5770, fax +49-7457-5880). These are lavish and non-compromising motors which look kinda weird - no glossy finish, no plugs between motor and controller etc., so they definitely won't tickle everybody's fancy. Nevertheless, these will be available if there's enough interest.
Motor length excluding shaft:: approx. 80 mm, largest
diameter: 33 mm, weight: approx. 230 grams.
|Side view - which shows the general layout. Left to right: 6 mm output shaft, carbon gearbox casing, steel ring gear for the planetary gearbox, front flange (wound from Kevlar/Aramide), iron rings (held together by glass and Kevlar/Aramide strips), rear flange (wound from Kevlar/Aramide).|
|The rotor (solid Neodymium) with front bearing and pinion.|
|Motor front, gearbox opened.|
|Motor rear with aft bearing and hall sensors. Part of the copper windings can be seen inside the motor case. The windings are mounted together with the iron rings, insulating layers and the front and rear flange parts, then reinforced and wound with Kevlar/Aramide and cured in an oven. A high temperature resin makes for maximum heat resistance.|
|Balancing machine with power supply and oszilloscope. The rotor is driven by a small electric motor and a rubber band. Because of the strong magnetic field of the rotor, the balancing machine had to be constructed exclusively from plastics and other non-magnetic materials.|
|The rotor bearings are held by parallelogram supports which allow them to move sideways. Any imbalance results in horizontal vibrations which are detected by photoelectric beams and viewed on an oscilloscope. Below the rotor, a light reflection sensor points at felt-tip pen markings (wide line at 0°, narrow lines at 90°, 180° and 270°) which are viewed on the oscilloscope too. This way, the exact position of the imbalance can be determined easily.|