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Old Sep 24, 2011, 05:18 PM
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Dave, you probably never will get that oblong one to perform the way you want it too. Not enough nose moment and you are missing the sweep of you heart. I have tried some of those too. Hang the motor out a couple of inches in front of the LE and it will be a different bird. Or do what I just did on my most recent chameleon wing, cut back your LE an inch or two and add some sweep. It might just improve some. I am guessing it just doesn't feel smooth like a delta or disc shape. Correct?
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Old Sep 24, 2011, 05:22 PM
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BTW, I think this would make a great flyer... Round section as the rear with forward swept elevons A w delta with curved back end. Kinda like my nutball deltas or bullseye delta. All really stable. That is probably why I am drawn to the shape...

http://static.rcgroups.net/forums/at...2-P9180007.gif
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Old Sep 24, 2011, 11:50 PM
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Could you post some more pics of the bw size please. I would like to see your gear up close especially underneath. Thanks
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Old Sep 25, 2011, 04:50 AM
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The back becomes the front... yes you are correct, that shape looks fine..

Here are the pictures.. The battery shown is a 1000 3 cell.. and with it at that position the COG is just in front of 30% at about 28 1/2%.. Using a 500 placed at the front the COG moves back, closer to 30%...
I have found this heart shaped model will fly at a wide range of COG's its not sensitive, but its at its best and is easy, just in front of the 30%
I have flown it with a very rearward COG.. It will fly safely but it does some weird stuff..

The oblong/oval shape is very sensitive to the COG which needs to be at a max of 22.5% back.. Its full flyable, but I prefer a less fussed model..
I am going to add a lower step to this, making it a KFm4, to see what difference that will make.. the two heart shaped already are KFm4..

Area wise.. the biggest heart shape has a 1/2sqft more area than a 32" circle.. which is a good max size for a Nutball or UFO
With any of these bigger is more docile and takes more storage room.. too big and the thing is not as much fun, too steady and slower to respond.. too small and the wind bumps it bad and it can be too responsive..
Remember I am one of the oldies so prefer to fly just that bit more sedately than the young ones..


Power wise.. the Blue Wonder has enough,but is not excessive, power for the middle 21" long heart.. I am going to swap it for an unused Axi that I have to see how well it goes then... I do like to have excessive power available to make easy work when using larger batteries..
With the much heavier Axi the batteries now go on the COG.. The power is doubled..
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Last edited by davereap; Sep 25, 2011 at 06:19 AM.
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Old Sep 27, 2011, 05:03 PM
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Today its a super day here...
Ive been out and flown the smaller and mid sized W wings after they have been modded..

The small semicircular tipped wing is now a KFm4.. this mod has improved the stability a lot..
serious evaluation on the small one.. ok but not super... It is let down by its poor elevator response.. the elevons at 45 degrees roll the model like mad, but when gliding in the elevator does not flair the model when the speed drops down low..
My thought on this is that the main area on the surface has been brought too far forward, so it results in the effective moment arm of the control surface giving less force.. the surface is not huge so the response is poor.. moving the COG back didnt make this better, its best COG is at 22.5% or just forward of that..

On the Blue wonder size, heart shaped, the control surface areas are positioned differently, all controls work very well..Its now running an axi motor giving about twice the weight and power of the Blue wonder.. This is a good combination ..performance is now superb in all ways..
The good COG for this one is at 28%, but its not at all fussy..you can move the battery about till inverted flight is as stable and level as the upright flight...If you put the battery too far back, it will do a climbing loop hands off no matter what way up it is.. it will however still be flyable..
.
.
KFm4 W wings get an evaluation (11 min 41 sec)
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Old Sep 28, 2011, 05:32 AM
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I had decided to scrap the smallest version, but now think I will remove the semicircle tips and try another idea..

I will stay heart shaped but have the elevon hinge line in a more conventional alignment...ie no rake forward..
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Old Sep 28, 2011, 11:37 AM
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Quote:
Originally Posted by davereap View Post
Ive been Sketchuping... here is a variation and is a more accurate cross breed

What do I need to open this file, beside a zip program? I can unzip it,but windows says it can't open the file.

Thanks.....Bill
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Old Sep 28, 2011, 03:01 PM
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@ Bill: you need sketchup.

you can find it here : Sketchup


Greetz,

Pesadilla
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Old Sep 28, 2011, 03:04 PM
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Quote:
Originally Posted by pesadilla View Post
@ Bill: you need sketchup.

you can find it here : Sketchup


Greetz,

Pesadilla

Thanks a bunch..........BILL
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Old Sep 28, 2011, 06:02 PM
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Bill..
Sorry just because I use sketchup I think everyone should... for foamies and all sorts of design it takes a lot of beating...
more info for our uses is here http://www.rcgroups.com/forums/showthread.php?t=920416

Question do I go with a straight trailing edge with the elevons cut out or use the semicircular elevons

Ive removed the semicircular tips from the smallest "W" wing replacing them with this new arc shape.. the KFm4 steps are aligned more with the curved delta wing.. However I am torn between using a straight trailing edge or the curved heart elevons..


I did some evaluation on the biggest "W" wing ... yep still flying well on 150W but a bit lacking in any vertical.. after hotting up the Blue wonder size with such great results, I am going bigger on this one as well... I have just put on an Emax BL2215/25 which will give 200W and another 8oz thrust.. I will say as they get bigger they also get more docile... same as any other model.. Nutballs etc...But with enough power it will go even better..
At the moment the 21" long Heartshape, Blue wonder size, overpowered with the Axi, is by far the best fun of the three... Its big enough to be stable but small enough to be well maneuverable, and overpowered goes like a good'n
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Old Sep 28, 2011, 07:05 PM
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I installed sketchup and it works fine. I have four projects in work, not going to get them done. I'm off to Conn next month, then back home at the end of Nov. and back into the projects. I hope to be able to start working on one of these "W's" about the first of the year. I'll keep tabs on your progress while I'm gone.

Thanks for all the info...............................Bill
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Old Sep 29, 2011, 07:42 AM
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More evaluation and the middle size of the three is still my favorite ... the big one is too docile and easy.. the small one, new shape, is needing finishing...
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Old Sep 29, 2011, 08:34 AM
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Another cool design....may have to try one of these this winter...
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Old Sep 29, 2011, 08:40 AM
gpw
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Dave , don’t you find it amazing that a small change in size makes such a big difference in performance ... ??? Seems just a few inches either way does it ... Curious , especially compared to full scale planes ...
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Old Sep 29, 2011, 03:28 PM
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Yes small to large makes a big difference in the flying.. so pick a size to suit how you like to fly..

The small one is now done..version3... Its got elevons square to the line of flight, and steps raked back on the wing, like it would have if it was a pure delta
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