Editing Synchronization gear (section)

=== Austria-Hungary ===
The standard machine gun of the Austro-Hungarian armed forces in 1914 was the Schwarzlose MG M.07/12 machine-gun, which operated on a "delayed blow back" system and was not suited to [[Schwarzlose MG M.07/12#Use as an aircraft gun|synchronization]].<ref name=Volker3p56>Volker 1992, pt. 3, p. 56</ref> Unlike the French and Italians, who were eventually able to acquire supplies of Vickers guns, the Austrians were unable to obtain sufficient quantities of "Spandaus" from their German allies and were forced to use the Schwarzlose in an application for which it was not really suited. Although the problem of synchronizing the Schwarzlose was eventually partially solved, it was not until late 1916 that gears were available. Even then, at high engine revolutions Austrian synchronizer gears tended to behave very erratically. Austrian fighters were fitted with large [[tachometer]]s to ensure that a pilot could check that his "revs" were within the required range before firing his guns, and propeller blades were fitted with an electrical warning system that alerted a pilot if his propeller was being hit.<ref name=Woodman19>Woodman 1989, pp. 200–202.</ref> There were never enough gears available, due to a chronic shortage of precision tools; so that production fighters, even the excellent Austrian versions of the [[Albatros D.III#Austro-Hungarian variants|Albatros D.III]], often had to be sent to the front in an unarmed state, for squadron armourers to fit such guns and gears as could be scrounged, salvaged or improvised.<ref name=Varriale1>Varriale 2012, pp. 9–10.</ref>

Rather than standardising on a single system, different Austrian manufacturers produced their own gears. The research of Harry Woodman (1989) identified the following types:

==== Zahnrad-Steuerung (cogwheel-control) ====
Drive was from the camshaft operating rods of the [[Austro-Daimler 6|Austro-Daimler engine]] via a wormgear. The early Schwarzlose gun had a synchronized rate of 360 rounds per minute with this gear – this was later boosted to 380 rounds with the MG16 model.<ref name=Woodman20>Woodman 1989, p. 201.</ref>

==== Bernatzik-Steuerung ====
Drive was taken from the rocking arm of an exhaust valve, a lever fixed to the valve housing transmitting impulses to the gun through a rod. Designed by ''Leutnant'' Otto Bernatzik, it was geared down to deliver a firing impulse every second revolution of the propeller, and fired at about 380 to 400 rounds per gun.<ref name=Guttman1>Guttman 2009, p. 194.</ref> As with other gears synchronizing the Schwarzlose gun, firing became erratic at high engine speeds.<ref name=Woodman20/>

==== Priesel-Steuerung ====
Apart from a control that engaged the cam follower and fired the gun in one movement, this gear was based closely on the original Fokker ''Stangensteuerung'' gear.<ref name=Woodman20/> It was designed by ''Oberleutnant'' Guido Priesel, and became standard on Oeffag Albatros fighters in 1918.<ref name=Guttman1/>

==== Zap-Steuerung (Zaparka control) ====
This gear was designed by ''Oberleutnant'' Eduard Zaparka.<ref name=Guttman1/> Drive was from the rear of the camshaft of a [[Hiero 6|Hiero engine]] through a transmission shaft with Cardan joints. The rate of fire, with the later Schwarzlose gun, was up to 500 rounds per minute. The machine gun had to be placed well forward, where it was inaccessible to the pilot, so that jams could not be cleared in flight.<ref name=Woodman20/>

==== Kralische ''Zentralsteuerung'' ====
Based on the principle of the Fokker ''Zentralsteuerung'' gear, with flexible drives linked to the camshaft, and firing impulses being generated by the trigger motor of each gun. Geared down to operate more reliably with the difficult Schwarzlose gun, its rate of fire was limited to 360–380 rounds per minute.<ref name=Woodman21>Woodman 1989, p. 202.</ref>