Skippydiesel wrote:garyb wrote:Hi
My Rotax powered Sonex has a 68 inch wooden GT propeller off a Tecnam P2008 .Static rpm is around 5100, Solo it climbs sea level at 1800 fpm at 70 kts, cruise 2500' 120 kts 5200 rpm and 5500 135 kts WOT it pulls to the red line 5800 rpm. The prop could probably do with a little more pitch.
Cheers
Sounds as close to perfect as you can expect, with a fixed pitch prop.
There is a French propeller maker E-Prop (
https://www.e-props.fr/) that seems to have an enthusiastic following here in Australia. Claims of a new approach & great efficiency improvements.
Skippy... I live in Argentina, importing anything nowadays is almost impossible... Super restrictive laws and my country is ranked 3rd in the world for inflation... Im the representative in Argentina for AERO Propellers from Ukraine :( But theres no way to get anything from there because of the war. Im also a collaborative and im kinda sponsored by a local Custom propeller manufacturer thats been making great propellers im currently running in all my airplanes... (Outperforming in every case Every known brand of ground adjustable carbon fibre props)
A ground adjustable propeller has ONE sweet spot... where all the blade has the optimum angle of attack. When a custom propeller is made, the entire blade has the optimal angle of attack for a given airspeed and prop rpm... So when you aim for static thrust (stol applications) climb (maybe the allround everyone is using) or cruise (for cross country or high altitude performance applications) The whole blade is tuned for that specific mission.
It takes decision... Where you want your performance, calculations... and sometimes a couple trial and errors... But once youre done. Its cheap, light and a great performer.
Having a good solid starting point saves calculations, and lots of wood chips flying in vain.... So thanks a lot for giving me that information, for me its literally precious.
PS: Once the "purrrrfect" propeller is done, I could even ship wolrdwide :)