Cédric Walter | Oct 8, 2020 | 0
Raptor 30 Wah Wah, Woof and poof
Raptor 30 Wah Wah is the term used to decribe the sound that comes from the autorotation hub engageing and disengagine from turning the mainshaft due to a poor running motor in the mid-range. It is usually induced during descents. Just say Wah Wah Wah Wah Wah in about a seconds time. That is what it sounds like. Many people including myself believe the best solution is to put a load on the autorotation unit by using a slipper. Or, you can chase the needles around richening the motor up.
Raptor 30 Woof is the condition where the mainblades go violently out of track occasionally stricking the boom in flight(“Poof”). Most often this is caused by using blades with an unstable chordwise CG AND slop in the rotor head. With the V1’s slop it was never a good idea to run unstable blades unless you work the slop out of the blade grips, cyclic control, and lower the headspeed.
Technically it is “aeroelastic instability” which allows the blade to “couple” or resonate in pitch in a multiple of the rotation rate. The Raptor trailing edge control arm can make it much more sensitive because of the “Delta” result. “flipping” the head goes a long way in “fixing” it