I flew McCutchen skywheels in the 80s. Love them. They had high inertia compared to aluminum Benson blades. That high rotor inertia made spot landings effortless.
One of the biggest advantages of wood rotors is the chord weights. My wooden blades weighed about 16kg but flew with a lot more inertia due to the small tip weights. The flexibility of wood is better as well. Nicest blades flying much less twitchy and can save you from a poor landing as they hang on for ages. Chord wise balance is important too. I flew a set of wood blades that were overbalanced chording 25% is normal. These were nose heavy at TY hat point and closer to 30%. They were rock solid. We hit a massive thermal at topped off the hall ASI at 80mph we barely moved. I suspect after people still keep dying in spite of stabs and high cg machines eventually someone will start experimenting with this and manufacture training blades, flexible chorfdwise and slightly overbalanced. Makes much more sense to stabilise the thing keeping us in the air and responsible for the sensitivity in the first place.
I personally think you have hit the nail on the head with regards to rotor blade construction. I had the good fortune to meet Ken Wallis in the late 60's, and he explained to me that the key to making the rotors, was flexibility. He mounted a weight box on the leading edge, which not only twisted the tip downwards, but also moved the C of G forwards as it progressed towards the tip. He described it to me, as being similar to the difference in behaviour as a tail dragger, compared to a trike undercarriage, i.e. the blade is washed out at the tip, due to it increasingly following the mass as it moves outwards towards the tip, a bit like the tail feathers on a dart. That was from a discussion I had with Ken over 50 years ago, so I'm not sure if I have explained it very well, but to be building and flying them right into his 90's, I guess he knew what he was talking about. Ken never used high C of G, or horizontal tails, so perhaps, more people should take more note of his calculations and blade construction techniques.
Autorotation Very intrigued by how these work and have been looking for an explanation. I even watched a video showing how a helicopter autorotates….with a positive incidence to the foil! Having spent the wee hours, hopefully, getting an answer, I think I see what is missing in explaining what makes the autorotation. No one is considering the full rotation. Think of it as three quarters. The rear quarter the segment is towards the horizontal and in disturbed air, so not doing much. Now the forward facing segment has a good upward flow across its whole length, and the negative incidence causes it to rotate. This is where the major force comes from. The leading side segment gives drag, though this is somewhat balanced by the push from the trailing segment, though still an overall slight drag against rotation, but far less than the positive rotation from the front segment.
Hi Peter - so just looking at the big two. Magni require the rotors to be sent back to the factory every 1000hrs for inspection whilst AutoGyro blades are life’d to 2000hrs.
once you get through mechanical attachment Im still persuaded by the integrity of extruded aluminium blades which could be fitted with mass weights as at one time some helicopter blades were
Why Multiblade rotor are so rare, specialy now ? What could be advantage/inconvénient ? An other question, why Carbon fiber for rotor blade so rare too ? Thanks for your Channel.
Thanks and I think there are couple things. On the multi blade question its just a weight thing for sport gyros and carbon blades there is a company making them gyrotech.eu but I think they are expensive v the alternative.
@@gyrocopterflyingclub6148 The gyro- tech are not that much more and you get superior quality control and construction love them on the RAF 2000 machines
@@z_actual how will that go in autorotation i flow two sets of rotors that where close to symmetrical both had issues as they had to be depicted significantly and lost lift as a result. However its possible it was other factors also. TheN8H12 is definitely good be sure to add reflex.
@@cameronlapworth2284 Im interested in the difference because 0012 is a very average foil within a predetermined less than 16% section, the 8H12 is expected to be a better performer but it is a laminar section and will suffer if it gets wet or dirty from dust, and dust is common out here. Wet not so much What I have worked out is, 8H12 dirty is just a slightly better performer than the 0012 which is untroubled in the same circumstance. 8H12 will generally be composite and therefore heavier than an extrusion, the net effect is a larger conning angle and additional power reserve But you have to factor in the machines weight with a heavier rotor blade, for which lighter weight out competes in all aspects of flight performance except sustaining power reserve.
If that profile flies, a true AG 18 section would skyrocket ya out of earth !! However i never saw any gyroplane with proper AG blades ... like the 8% thickness, 1% camber, AG 18. It was a theoretical improvement lost information ... and there are others ...
Reading about autogyros, I fall 2-3 times over the expression, that "helis have to have positive pitch rotors, while gyros have to have negative pitch rotors", but without further explanations (was the rotor-pitch meant, or the pitch of the blades of the rotor, for example???), and a search didn´t lead to more clues for me... I´m stuck now, and don´t trust anything I read, cause the loose way of wrtting in the internet either lets me back confused, or the too exact way of writing lets me back with headaches (cause I understand not a word). Can anyone explain what I read there, and what this expression actually means, or propose a source, where I can find the answer ??? Thanks a lot á priori for any answer...! I´m always, of course, interested solely on simple, fixed-pitch-gyro-blades, so, nothing complicated or special, but that what a Bensen B-7 or B-8 would have (cheap, smal gyrocopters, without fancy rotorheads that can alter blade-pitch). For my part, I interpreted this expression as follows: Helis moving forwards, have a rotor-disc-plane tilted slightly forwards (positive-pitch-rotor), while Gyros moving forwards, have a rotor-disc-plane tilted slightly backwards (negative-pitch-rotor)... (???)
@@gyrocopterflyingclub6148 Sorry, no sources. When i searched again, I couldn´t find it again, but I tripped a couple of times over it... Thanks anyway, and if u can imagine of any meaning, then please tell me...
a.k for some reason, when clicking on your answer, I cannot find the answer anymore, not even the first 4 lines, that I were able to read already in your answer´s "preview", but those confirm what I belived (of course I´ll have to read the whole anwswer to be sure of anything ;-) so, thanks a lot for the answer anyway, YT seems to have a bug sometimes with the updating of the comments´-status... ;-)
