@ Aktung: Yep. It is not the magneto switch, but i guess it is close enough
It is the
"Bosch Anlassmagnet", only used for
starting the engine. With this system you did not need to manually start the engine.
You crank the propeller to fill the combustion chambers with fuel mixture, until any piston of its engine is in top dead end
and ignition position, then you crank this starter magnet connected to the spark plugs, which produces a shower of sparks. One detonation of the mixture is enough and the engine will kick-start to rotate, then you quickly switch on the aforementioned other magneto switch, so the double ignition coils take over.
A pilot would thus be able to start his engine alone, without help or electrical starter.
This is the whole Anlassmagnet:
The "Oel" is being filled in through the upper screw, the electrical coil is surrounded by oil for insulation and temperature distribution, and had to be filled up now and then.
"In a lot of old films one sees the scene again and again in which the fitters turn the propeller at the start and thus supposedly "crack" the engine. This is only partially correct, rotary engines ala Gnome Rhone with a low flywheel mass were started like this, but this does not apply to german in-line or V- engines. ...
Even in the early days of aviation, aircraft engines had magneto ignition, and so on the "dashboard", there was a strange crank mechanism next to the ignition switch. This apparatus was a starting magnet with which a stationary engine could be "cranked". The prerequisite was that the engine had been cranked a few revolutions beforehand in ignition position "Off" and now one cylinder was set to "O.T." (Oberer Totpunkt/Upper dead end), the combustion chamber full of ignitable mixture. One turn of the magneto and the cylinder ignites. If you switched to "ignition" fast enough, the engine would run."
Willem helped to build this Fokker D.VII, with an original restored Mercedes D.IIIau engine. AT 2:00 you can hear the pilot whirling the crank of this starter magnet, and the engine starts:
Over to you!
