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May 18, 2014, 08:35 PM
It's a fine fiddly business.
Robert R's Avatar

Weight is your mortal enemy


Quote:
Originally Posted by Gerald Sharp
Has anyone added ailerons to this J-3 Kitten model? If so how did you go about it and how well did it work out?
Hi Gerald,

I have Pat's J-3 kitten in my building queue as well.

I believe weight is so critical in these very light models you might be happier building it as designed.

I have not tried ailerons in Pat's Kitten, but I did rebuild a damaged wing in my Stevens Aero Carte Postal. The Carte Postal and the Kitten are about the same size and weight. My wing was about 20%-40% heavier that the wing as designed. It flew like a DOG with my wing. It wallowed on the edge of a stall at full power.

I rebuilt a 3rd wing from a second kit with good light wood exactly as designed and it flies beautifully.

My conclusion is that small ultralight models tolerate extra weight poorly.

That being said with a 28 inch wing span a single, central linear servo might be used to drive both ailerons via a wire through tube mechanism, but you might end up with a plane like my wing #2 Carte Postal. The worst that could happen is that you would have to build a second stock wing.

Let us know what you decide.

Robert
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May 19, 2014, 08:41 AM
Neophyte hacker
portablevcb's Avatar
I second that. I've converted quite a few planes to ailerons (including one of Pat's designs) and they always have significant weight gain. Some turn into dogs and some just fly fast. Neither of which would be good for a J-3. You may also get a lot of adverse yaw, which is not difficult to deal with IF you know how to fly with rudder and ailerons, or, you mix them properly.

There are also some who have put ailerons on smaller models without much weight gain. They are usually VERY good modelers and experienced at small model building.

If you haven't built several of these little ones before then I'd stick with Pat's design.

Keep it light!!!

charlie
May 19, 2014, 08:55 AM
Registered User
philipa_240sx's Avatar
I did the aileron thing to an Earl Stahl designed Fleet Canuck @ 24" ws. using Parkzone UM T-28 gear:

https://www.rcgroups.com/forums/show....php?t=1835508

I never updated the thread, but I did maiden it and was sorely disappointed. Too much adverse yaw and required full aileron deflection to perform a mild bank. She just never really flew well. With a bit more mechanical aileron differential and perhaps more aileron chord, it might have worked out better.

As for the Canuck, I rebuilt the wing without ailerons and it flew wonderfully as a 3ch model.
May 19, 2014, 02:55 PM
Registered User
Eclipse_7's Avatar
The clipped wing 26" J-3 I built a few years back used the same power setup as recommended on this kitten. With ailerons and 2 extra servos mine came in over 3 oz, but still had plenty of power. Never experienced any adverse yaw above what most high wing planes have.

That being said, the 30" Dumas Aeronca I built afterwards has a terrible time with adverse yaw.



This is the wing for my J-3, its got quite a bit extra structure to accommodate the ailerons and servos, plus the weight of the servos and extension wires.

Scratch built 26" J3 Cub (1 min 31 sec)
May 26, 2014, 06:22 PM
Veni Vidi Volavi
Brian Allen's Avatar
Got the J-3 Kitten out for another test flight today. My flying buddy Ron worked on the wing and managed to get the twist in the one panel out. So the little bird flew much straighter today. Looks very nice in the air. Did notice a ballooning tendency when power is added, need to check the downthrust setup as the power off glide is fairly flat.

Nice flyer all in all.

Left my camera at home so I was not able to take any pictures. Maybe next time!!

Brian Allen

Veni Vidi Volavi

I came I saw I flew
Dec 07, 2017, 12:49 AM
It's a fine fiddly business.
Robert R's Avatar
I am doing a J 3 Kitten to Flying K Skyraider 1 conversion thread.
I love the design but I don't want to clutter up Pat's thread with my all too frequent Robert trails.

https://www.rcgroups.com/forums/show...n#post38762328

Brian we wants video!!!

Robert
Dec 21, 2017, 02:40 AM
It's a fine fiddly business.
Robert R's Avatar

The Beast is Extinct - UMX advice please


I am running into a little bit of trouble with the systems end of things in my J3 Kitten to Skyraider 1 conversion.

The Kitten calls for the innards of the UMX Beast which is now discontinued along with its innards. That said, I think the UMX Timber receiver would work perfectly well. A DSM2 6 Ch Ultra Micro AS3X Receiver BL ESC EFLU4864 is available from Horizon Hobby. https://www.horizonhobby.com/dsm2-6-...l-esc-eflu4864

I already have an eflight 180 out runner with bullet connectors.

My Questions

What kind of connector is needed to plug the 180 motor to the brick ESC power output? I will have to cut off the motor's bullet connectors and soldier on what ever connector fits with the brick.

What kind of male connector fits on the UMX 2s battery for charging? https://www.horizonhobby.com/280mah-...-p-eflb2802s30
Once I figure how to connect to the battery lead I can soldier one of my connectors to hook the other end to one of my several good lipo chargers.

Thanks for thinking about this with me.

Robert
Dec 21, 2017, 09:41 PM
Registered User

adverse yaw


If my memory is serving me right, high-winged Aeroncas were rudder-priority airplanes, Turns were initiated and terminated rudder-first, almost as if the ailerons were used to center the ball, not make the turn. I can imagine how a model would also behave similarly. I think aileron rigging matters, too, lots of up, very limited down.


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