I've just started flying foamies, and am using a 3dfoamy Raven. When I harrier the wings wobble from side to side. I have mixed in up flap (both ailerons go up when pulling up elevator) up to about 45 degrees.

Any ideas what i'm doing wrong?

Thanks

you can put the ailerons back to normal that won't help on a flat wing foamy. Try adjusting the CG. I mite be extremely tail heavy. Foamies do not need to be tail heavy to do aerobatics. And if all that don't work it may just be the plane, some wobble and some don't.

Ill give it a go, I have been moving tyhe C of G back steadily, maybe I went too far.

Thanks for your help.

Often times that can also be a slightly high wingloading, what's your flying weight on it? In addition you want to be at a high enough angle of attack in the harrier that you are well beyond the critical angle of attack, ie the angle of attack at which the aircraft will stall. . . if you are just a little bit beyond it then you may see the wings wobble from starting to transition back and forth between stalled and flying. . .try a little more throw/stick input, and a higher AoA.

I'm using a Thunder Power 3S1 2100 mAh battery for an all up weight of 498 grams (17.59 oz). Maybe a smaller battery around the 1200 mAh mark would improve this?

It's worth mentioning that the wobble is around the roll axis (ailerons), not the pitch if this helps?

That is a very big battery to be running. I run the Thunder Power 1320 3 cell and the 830 3 cell. I don't very many people running over 1320's. Angle of attack will effect like davef says. Some planes angle of attack is very high and some are alittle lower, you have to find the "sweet spot" on your own.

That would explain the 22 minute 3-d flight times

This is my first time into electric and foamies. Ill maybe try the Thunder Power 1300 mah battery then, or do you feel a 700-900 mah battery would do?

I'm using an AXI 2212/34 motor.

If you like 5 minutes worth of wild fun the 830 will do but if your looking to get 10 minutes and over go for the 1320. I usually stick the 830's in when i want the lite weight and want to really rig it out for just 5 minutes.

Thanks for the input, ill order the 800 and the 1300 battery packs today. Nothing like trying them out.

Something that helped me on my shockflyer is a lot of expo on the elevator and as mentioned earlier I was too far back on my CG. Something else as to not state the obvious but it helps to vary the throttle almost like in a hover. Just my 2 cents.

Yeah, wingrock as you describe is pretty common really. I am setting up a 3D Foamy Raven (Depron, Pro kit) powered by an AXI 2212/34, and decided on the Apogee 830 3s1p packs, I bought three of those instead of two 1050s. My run time estimates were around 10 minutes (over actually) based on my flying style with the 830s and 12 minutes with the 1050s. . . and a weight savings of .42 oz which I figured I needed more than those extra 2 minutes between battery swaps. Long run times are nice. . .but if it's 3D your after then so is a low wingloading.

Given what your all up weight is I that battery may solve the issue, its giving you a little heavier than ideal 3D wingloading.

try to compesate the wiggling... though smaller planes are wigglier then larger, so it might be hard to be fast enough to corret it.

I tried that, but I seem to aggravate it more.
I should have the lighter batteries by today or tomorrow so ill try the weight reduction. Whatever the outcome ill post up feedback.

I'm now flying the Raven with 1320 mAh and 900 mAh Li-Po's.
The wobbles are still there but the frequency has reduced ie the wobble is slower.

Also mixing in up aileron (reverse flap) dosent seem to make much difference.

Just wondering if anyone else found a cure for this.

Whats left just mite be in the design.[] I just finished up flight testing on my new Edge 540. At first it had the same problem. I had to physically change the airframe positioning to get it to go away. Now I have the most rock solid, smooth flying 3D plane I have ever flown. It will be available in 1 week to everybody. It takes some time and effort to design foamies that fly good.

So what changes did you make?

elevator placement is crucial, go figure. Engine thrust line plays alot in the part. Even the spacing (vertical) between the wing and elevator. I have been making my test planes from blue core fanfold. then when I'm happy with them I produce them from Depron. We had to completely build 2 Edge's before i was happy, thats not even including all the cutting and hacking of the first one we did before we built the second one.

Some planes will wobble a lot less then others in the harrier. A nice one I flew all last summer was the Mad Taco from flyingthingz.com. this foamy was SO stable in the harrier and hover. The most fun I've had flying in almost 30 years with that thing last summer! I just try to find planes that make me look like I can fly well to solve these problems My motto is "what you can't make up for in skill make up for in design"

My perception is that 3dfoamy are some of the best and state of the art designs out there (thats why I bought some), and that it's my flying that's the problem.

The Raven does fly superbly, and after 10 days of flying foam I had my first flight on a flat calm day with a light (900 Mah) battery. It is a pleasure to fly, and still does loads of things I don't know the name for. It's wild, extreme and loads of fun, so i've plenty to go at for now.

After all of this, it probably is my flying [:-]

Hello Mark,
Have you tried to flat spin her into a landing yet

Spiro

I have an update to the wobbling harrier and it's not wehat I expected.

Yesterday my back order of propellers arrived. I changed to the reccomended prop for the motor, and hey prtesto - no more harrier wobbles

I was using an APC-E 10x7. I'm now using an APC Slow Fly 11.4.7.

I have more power, longer battery life and more vertical performance.

Sometimes solutions come from the strangest places. I always knew the correct prop would improve some of the power handling, but fixing the harrier wobble?

Comments anyone?

Thats pretty wild. I would have never guessed the prop would correct the wobble. I aready fly the APC 11x4.7 , I do like the props. Learn something new all the time.

It's funny eh? Sometimes the solution comes from strange sources.

Where's the best c of g on a shockflyer for 3d? right in the centre of the 2 cm c of g range?
Thanks
Frey Poulson.