GR-2B - Flexplate - Micro autogyro
260 views · Published 27 October 2015 · 2:50 · Indexed 29 October 2026
Channel: RCmags · 2015 · Entertainment
A reworking of my GR-2A. I extensively modified the previous version by shortening the tail boom and removing the old landing gear. Likewise, the caster from the steerable tail wheel was removed. This improved landing stability, making the aircraft less likely to ground roll. More important than both these changes was a modification to the rotor. Instead of allowing the blades to flap freely on a hinge, they now rest on a thin flexible plate; A flexplate. This design is much simpler than the previous rotor head but allows flapping to transfer torques to the fuselage. Three things became apparent from these combined alterations: 1 - The controls appeared more aggressive. A greater rate of roll was possible. 2 - The controls had a greater time delay between control input and fuselage reaction. 3 - The model was more sensitive to wind gusts. This could be seem by small attitude changes in flight. These changes made initially controlling the aircraft daunting. The greater control delay made it harder to counter gusts effectively, and the greater aggressiveness generally meant an over correction. To get around these issues I doubled the size of the battery, moving the CG of the model forward, then halved the control throws. Both these changes made the model much more controllable. It is noteworthy that these control quirks may be due to the feedback the servos now felt from the blade flapping. Servos have a limit on how much torque they can counter before seizing. It's possible the greater control throws loaded the servos sufficiently for them to seize for instants during flight. This would explain some of the instability. Overall, with some adjustment, this model flew quite stable and was mechanically very simple. Music is: Fukurokouji - El Huervo
