Vario Benzin, 4-bladed rotor head. roughly 1800mm rotor diameter, with asymmetric blades.
The original builder of the helicopter flew with the blade angles -4 to +10. (1200 RPM) So I have that set. What are some suggested safe values to start for LAND_MIN and ZERO_THRUST? I understand they may need to be tuned, but I’m looking for a safe starting point. Thanks.
Allister,
H_COL_ZERO_THRST is mainly used for the yaw to collective compensation. I believe it is also used to determine the takeoff collective but that is if you aren’t using the leaky integrator (which is the default) for the I term management. But it is always good to set this as accurately as you can. I think a good starting point might be -1 deg.
H_COL_LAND MIN is more critical as it is used to determine when the aircraft is landed. I would set this as low as you can without incurring to high of vibrations while running at operating rotor speed on the ground. If you can be at the operating rotor speed on the ground with -4 deg collective pitch, then use that value. If not then raise it 1 deg. However, I would stay at least 2 deg below what you think is zero thrust collective pitch.
Is there a parameter in the .bin log files that shows collective pitch in degrees or just extrapolate from the RC3 value? And if there is a high level of vibration on the ground at -4 should I bump up the H_COL_MIN?
Hi @Allister, there is no collective pitch angle logged, but you can look at CTUN.ThO and remap it on your collective angles range.
Okay, that makes sense. Thanks!
You could bump up H_COL_MIN and of course you’ll modify H_COL_MIN_ANG as well so it is accurate.
But you may want to just adjust the stabilize collective curve. You could raise IM_STB_COL_1. Might be easier until you find the collective that works best. Remember to raise H_COL_LAND_MIN to that value so that it won’t go below that value in loiter or other modes with auto collective.