RE: kaos wiggle
 

Hi Ed its funny i looked up kaos and super kaos only to find someone with the correct cg for the 40 size kaos (about 20 yrs old ) i bought at auction and got side tract into the wiggle info center seems there is a lot of different opinions on how to correcxt it from adding pieces to taking off pieces and now is it the same airplane but getting back to the original thought does any one out there have the plans for a bridi 40 size kaos with the cg on them i would realy appriciate the info thonks BOB

RE: kaos wiggle
 

hi MY SUPER KAOSMAJOR KIT BASHEDone of my best flyersknife edges on only rudder-SHE FLYS ON RAILS flying here for 15 years and always exciting daysOS 61 SF- on a MAX black exhaust-cut down 1/4 inch-which will remove the baffel-a very awesome soundLOVE THIS PLANE ENJOY REGARDS TONY "the omega man " think pink !!!!!

RE: kaos wiggle
 

hi OH YESshe does not wiggle-my fin is in a pattern stylean do run a 13/6 or 13/7 APC on your OS 61 SFas the variation and design of 60 size engines from the older ones to the newer ones can make them difficult to prop correctlyi had this engine on a 12/6 for a long time only to learn on RCU -i was doing it wrong for this long stroke enginegot it right nowthanks to all who live here and HELP!!! REGARDS TONY

RE: kaos wiggle
 

More vertical stabilizer should help, or a dorsal fin.

RE: kaos wiggle
 

Dan is right on this one!
Yes, mechanical problems like springy linkages could be a problem, but missing or inadequate wing fillets have caused the Kwik-Fly dance. Minor differences from one airframe to another will easily dominate the result, which is why so many Kaoses do not wiggle, while most Kwik-Flys did. Sub-fins and dorsal spines can only help stabilize the plane but if the flow from the wing/fuse joint is chaotic (how poetic) then the original problem will remain.
Regards,
Dean Pappas

RE: kaos wiggle
 

Laughed my ass off!

RE: kaos wiggle
 

RE: kaos wiggle
 

This wiggle thing sounds like a case of turbulent airflow generated at the wing/fuse junction (and perhaps around the canopy too) due to lack of streamlining (i.e., wing fillets), and in some cases compounded by excess power, on a design with an extremely thick airfoil. Further, the lack of airfoiled empennage is simply unable to smooth things out before departing the TE of the rudder - especially at high velocity.

Anyone with access to a wind tunnel at a university (used to but no longer...), could probably verify this [8D]. I'd bet that significant vorticies (eddy's) would be observed off the end of the airframe. Widening the rudder TE, as has been suggested, would lessen the wiggle effect reason for which we now see it on 2m F3A rudders (among other reasons).

However, I'm not sure that I buy the Kaos as being "on the verge of instability at high speed". To me that sounds like the description of an F/A-18. A model with a wing loading and planform such as the Kaos hardly strikes me as almost unstable. If it was, a little excess of design speed and one wouldn't be able to control it in maneuvers.

As a side note, apparently Hornets would be crashed regularly as a result of pilot input in the absence of it's interpreting on-board computer. I'd venture that most modern design fighter jets qualify as being on the verge of instability at high speed - thrust vectoring designs such as the F-22 Raptor particularly so.

Speaking of which, here's some serious wiggle: http://www.youtube.com/watch?v=faB5bIdksi8

Talk about elevator deflection going berserk! Electronic system failure to regulate pilot input.

Comments on this recent crash include the lack of use of "sufficient adhesive" on some sections of the raptor causing portions of the plane to be sucked into the turbofans... and I thought that sort of thing only happened to me! :D

I wonder how much epoxy is used on a 300M plane... 1M!? That'll teach us to save 100 grand! Maybe we should suggest Gorilla glue! Sorry... It just always blows my mind when you read statements like that.

David.

RE: kaos wiggle
 

Additionally, no one appears to be taking such things into account as piloting style (i.e., letting go of the rudder stick instead of moving it back to neutral). Couple poor piloting style with less than optimum servos or linkages and you can come up with a lot of mysterious aerodynamic characteristics for any design.


Ed Cregger

RE: kaos wiggle
 

Uhhh.... Not buying that one Ed. I thing Jason has some pretty good piloting skills....
If you look at my uncommented picture on post #4, it shows the prop vortex as spiral air moving around the plane, not just air moving directly backwards from the prop. I think it was Model Aviation that had a great couple of photo's showing the air moving around the plane as someone held a streamer behind the prop. The corkscrew action of the air moving across the plane will be tighter with a low pitch prop or longer with a higher pitch prop. My guess is that with certain pitch props moving at certain RPM is creating pressure differentials on either side of the aircraft creating a "wiggle". Omitting or changing the canopy, tail shape, propeller pitch, or RPM, MAY just be enough to accentuate the "wiggle".

Just theorizing.... FWIW.

RE: kaos wiggle
 

I'm not critiqueing Jason's flying abilities. In fact, let's leave Jason out of this discussion.

I am saying that old bad habits, crappy servos, etc., have caused many a design to receive a bad reputation. Master pilots are not exempt from owning a few bad habits.

None of my Kaos models, including, and especially the Chaos series, ever wagged their tails regardless of how fast or slow they were flown.

I AM NOT saying that anyone else is wrong when they say they have experienced the wagging tail syndrome. I will take their word for it, although it would take a bit more of an investigation for me to be convinced that it was a characteristic inherent in the design.

I do know that differently shaped canopies and even their position on the fuselage can have massive effects on the flight characteristic of any design. Ditto wing fillets, etc.


Ed Cregger

RE: kaos wiggle
 

Ed,
The original topic of this thread is the Kaos and an inherent "wiggle" as noticed by more than one person. The discussion in this thread pertains to the reasons why this plane "wiggles". You commented that it could be related to piloting skills amongst other things. All I pointed out is a TOC and highly accomplished pilot has experienced the "wiggle" so the piloting skill comment isn't valid.
If you took offense to MY theory then I appologize. That portion of my post was not directed specifically at you.

Regards

RE: kaos wiggle
 

The fillets on the Kaos were there for a reason. They were not only aerodynamic, but structural as well. The Kaos had no fuselage doublers so the large fillets were the only strenghteners for the balsa sheet fuselage sides. BTW this plane is a glassed and painted fuse and tail, with an Ultracote wing, and as mentioned, shaping the fillets correctly was by far the most difficult part of building the airplane.
Scott

RE: kaos wiggle
 

Scott,

once again, beautifully done Kaos.

Say, I'm impressed with the evenness of matching between your painted orange fuse and the UC. Photos usually show a better match than real life so I wanted to ask how close you feel it is and if it's good, what paint did you use? These days it seems that as far as modeling paint we're down to LK, KK and Nelsons.

TIA, David.

RE: kaos wiggle
 

Thanks for the compliments. The paint is a perfect match for the ultracote, even though I rarely use film covering. I took pieces of it to my paint store and had him computer match the paint to the ultracote. I use Valspar 2-part polyurethane primer, color and clear, and I occasionally add some pearl to the clear to create different effects on some paint jobs. I like orange because it is a very visible color on the pylon racers I normally fly.
Scott

RE: kaos wiggle
 

I had several Sig kiwi's that wiggle, and buy the time I got to kiwi4 I had fixed the problem by lenthing the fuse about 4 inch's and widening the rudder 1/2 inch.On the kiwi the wiggle possibly comes from a short coupled setup.

kiwi4