German propeller question.

[Revi16]

Can someone explain what the German propeller pitch indicator is indicating? Propeller pitch 10:30, 11:30, etc???? Whats high pitch and low pitch? What were it's position/time limits (3:00-12:00)?
Why two hands like a clock?

I understand how a variable pitch propellor works and what fine/course high/low pitch is, but how does that correlate to a clock?

Regards,
Mike

[Kuba Plewka]

Mike, as far as recognized - the 12 o'clock position on a pitch indicator was a low pitch set on engine start while 6 o'clock was for a feathered prop blades.

[Revi16]

Thank you!

[schwarze-man]

Hi Revi!
The prop pitch indicator shows blade angle on a analogue clock type display. It was used with VDM mechanical adjustable props where a direct mecanical link could relay prop pitch as a function of the adjusting mechanism. The display shows 1 degree of blade angle change for every 10 min so, 1 hour equals 6 degrees of adjustment. The low pitch position was usually 12 o'clock and equalled about a 25 degree pitch setting. This was usually the "Take-off" setting. The fully-fine stop was usually at 12.30 (22 degrees) and the fully coarse stop was set at various settings upto around 06.00. The clock would therefore run earlier as speed rose and the pitch was increased. Pitch change max rate was around 1.5 to 3 degrees a second- depending on installation type.
HTH-SM