Fenrir flights 09 – 15 were to find a good power system setup. Flights 09 – 11 were performed on October 10, 2014 using a 4 cell battery, Hacker A40-12S V2 motor, and Hacker X-70-SB Pro speed controller. Flight 09 used a 12x10 propeller and Flight 10 used a 13x10 propeller. On both these flights it was observed that the speed control dropped RPM shortly after reaching full power and airspeeds were much lower than expected. For Flight 11, a 14x7 propeller was used, which was the baseline propeller for previous flights, to rule out the propeller as the cause of the RPM drop. Again this drop was observed. Testing conducted following the flights on October 10 indicated that the batteries were to blame for the RPM drop observations.
3 cell batteries were used for flights 12 – 15. Based on calculations a 12x12 propeller was used for all flights with the same motor and speed controller as before. These flights did not show an RPM drop and the airspeeds looked like the fastest seen on this aircraft. Flights 12 and 13 were straight and level manual flights. Flight 14 included a manual pitch doublet during the straight and level flight. Flight 15 was straight ahead, but included approximately a 50 foot climb, level off, and descent.
Winds were light and variable for both days of testing.
Fenrir Flight 13.
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