Herman wrote: ↑Fri Apr 22, 2022 3:14 pm
Re Regis/Hawk mixer:
Not sure I can follow your ratios and the mixer is upside down to me so forgive me if this does not make sense; but to me that looks the same as a standard mixer except for the rear pulley. This pulley means that if tension in Z is high it will be moderated by pulling the attached loop thus exerting a pull on C until the tension is even. Some might, loosely describe, pulling on C as reducing camber, but I would prefer to think of C as the forward part of the trailing edge, where a pull on it could actually be increasing camber. These are just first thoughts and are not necessarily correct.
Very interesting thought . I didn't want to enter in this reflexion and loose people in this "tutorial thread" but you're right, we should now;
my opinion, no condescendance here
- you are absolutely right the risk of Z pulling C ; this is exactly why I was affraid of the original Jacko even more than on Hawk; however as you said, a risk persist in Hawk as well: if we consider that Z could pull harder than C in a phase of your ride, you then loose camber as you guessed, but you also loose some AoA since Z get longer ... total change in the kite... this could lead to a sudden loss of power without rider input (no instability at first sight which is essential, because B, C and Z goes in the direction of more stability)
- this mixer, as my old Malabar one (and another intermediate we could imagine by connecting the line to B instead of C ) is based on an assumption that tension in Z always remains lower than C (or A in case of Malabar); which is mainly the case in steady winds on a foilkite where front lines have far more pressure than rear lines (on a foilkite, about 70%-80% front line vs 30%-20% rear line) => so C bridle has more tension and remains the master and is always kept as far as possible from the kite (fixed whatever the tension in Z); while Z bridle has less tension , is the "slave" and position is piloted by the position of the rear pulley when its tension is less than C.
- but indeed , in case of punctual turbulence or a special foil kite that would have hard bar pressure (like Conceptair Waves) , I think we have this dual mode risk, fortunately not leading to kite collapse at first sight as said above. So not catastrophic if it happens rarely.
- I can add that from what I discussed, bridle locations on Hawk and kite "setting" was done to decrease the bar pressure; maybe to compensate for 50% higher pressure of its special mixer but this also goes in the direction of a "compatibility" with this mixer, keeping Z always as the slave vs C since lower tension in Z by design.
Last remark about camber : I think your last question about possible increases camber is not true : If Z pulls on B, the camber (e.i. distance between C and the chord (A-Z) will decrease, so less camber)