Arrrrrrrrrrrrgh! Plane cannot be controlled!

[realbob]

HI, I had few crashes in the past and now I upgraded to brushless. This is my 1st flight, but the plane is always leaning to the right. If I do taxi on ground all is ok, so not a rudder issue. could is be COG, bad wing placement?

I checked very quickly and could it be because it is tail heavy since with brushlees less weight in front?

Here is a small vid, please help!

[toff]

Defineately tail heavy, but with the control issue, I have to ask, have you put any down and right thrust on the motor? From my own experience, I can say that too much right thrust makes a nearly unflyable plane, coupled with tail heavyness, that would probably do it.

'Nose heavy, flies badly - tail heavy, flies once.'

[realbob]

WHat does thi means???
You put any down and right thrust on the motor

Don't understand.


To let you know, I bought a motor mount which is made for SUperCUb, so already have an angle to it.

[toff]

Thats what I meant - angled to the right and down.
Hmm, okay, Correct the CG, so it's slightly nose heavy, and try a test flight again. If it's still doing it, I'd look for a binding rudder servo.
Also, do you range check prior to flight? Could be a loss of signal error.

[flydiver]

CG:
With ALL stock components installed the C.G. is 2.25" back from leading edge

Also do a right/left balance test along the center axis. Balance it out as necessary.
Check your wing root isn't deformed or the wing on too far back or crooked.

[Dillzio]

If you have changed your motor without checking that the centre of gravity is still OK after the change then it's little wonder you find your plane uncontrollable. The stock motor+gearbox is quite heavy, I did weight is once upon a time and post it to the forum here but I can't remember it now. Tape a couple of large coins to the very front of the cowl and see how that goes. If you have more power than the stock cub, you may be better off setting your CG to 2 inches from the leading edge, that way the nose will be less prone to shoot up into the air at full throttle. Might also be a good idea to add a couple of small washers to the top of the motor mount to get a bit more down angle, I did it to my cub and it works a treat

[realbob]

Well, after balancing to be very slightly nose heavy (added about 75g), then balance from left to right (added 140g) which seemed to be very too much wieght, but plane was balanced. I threw the plane... it stayed level for 2sec, then same thing! But now since the was higher and I wasn't able to recovery at all, big badaboom! End of the cub Weels, wing sruts, wing in half, lights, tail!

Other thing.... since I went brushless, maybe I read to fast on this.... what you think?:

1- Changed motor gearbox with motor mount which is made for SC.
2- Changed motor to park 480.
3- Changed ESC for a new one.
4- Changed remote form DX5e to DX7.

Point 1 and 2 seems ok, but 3 and 4.... I should have stick with my DX5e since maybe my DX7 which I never flown with has some issues? Is there a way to test the remote perfectly before flying? Or it may have a setting which moves rudder when giving more power?

The ESC, how can I test this before flying?

I strap the plane to ground and then do like if I fly? DO taxi can help but throttle is not high like when flying, so not a good simulation.

AND NOW! after I reread the brushless mod..... I didn'T change the servos... Could this be it? Mine are stock but have 3 wires and worked well in taxi....

[flydiver]

ESC - buy a decent model about 20% larger than the highest amp draw of the motor when PROPPED RIGHT.
Yes you can hold or tether the plane but do not do full throttle for more than 30 seconds. Static testing can overheat the motor.
If you don't have a wattmeter.....GET ONE!
You are working in the dark when you start putting your own systems together without one.
Unfortunately the Chinese spec are something to take with some skepticism.

Sure, you can check the RX range. Same as the DX5e.
Read your manual. Idea is the same, how you do it may be somewhat different.

Servos should have been fine if they were not broken AND you set the new TX up right. Setting it up correctly is your responsibility. If you screwed up the settings it could make things very wrong indeed. Getting used to a new computer TX is not walk in the park. Most TX instructions suck!

Doing a COMPLETE and CAREFUL pre-flight and range test on a new plane are critical. That should have included a CG and balance test along with ALL control surfaces, deflections, and functions. Cutting corners.....costs dearly.

If you aren't totally confident....get an experienced pilot to check it out and maiden it.

[ginginho]

I'd add to Fly's wise words above, once repaired I'd suggest finding a nice large space of tarmac and poodle the bird around checking that the inputs you put into the radio do what you expect. I've seen too may crashes due to reversed servos (see my avatar. In this case up was down and vice versa).

[realbob]

Yeah I guess I was in a hurry to try all the mods also at once!!!!

Can I keep fuselage or it may have some small cracks and would be better to change? If nothing visible I keep?

[flydiver]

Bend, flex, pull, inspect.
If no damage, no problem.
If cracked or broken > fix or replace. How much is up to you. Generally the Cub can be fixed more than a lot of people think in the beginning.

[realbob]

Here is some pics of my super crash!!!!