bhpd1438

Yesterday I was flying my J3 (in a little too much wind probably). the wind shifted suddenly on final approach and I had what i would call more of a hard landing than a crash. anyway, after my "hard landing" my control inputs are all backwards. I pull back on the stick, and it pitches down, and left and right are now opposite. i have tried everything i know how to do to fix it. does anyone have any suggestions? thanks, matt

phase_boy

Matt,


I own a Kyosho Piper J-3 Cub, which is essentially the same as the ParkZone Cub. Though I have never experienced what you're talking about, I have been able to reverse and/or mix the controls by moving around a jumper on the receiver/amp in the plane. The ParkZone and Kyosho Cubs might have different electronics inside, but I suspect they are quite similar.

There is a jumper on my receiver/amp that can be in three different positions, or removed entirely. Perhaps the jumper fell off (the jumper in my plane was very loose) during the hard landing.

Do you know what I mean by the "jumper?" If you don't, it's a small plastic/metal piece about 2mm x 2mm x 1mm that sits on metal "pins" on the circuit board of the receiver/amp. Check if the jumper is still there. If it is, make sure it's on the correct two pins (should be in the manual). If you've lost it, you can get another jumper at any computer store. They are standard jumpers (at least they are on my KYOSHO J-3 Cub!).

I'm not sure if the transmitter that comes with the ParkZone Cub can be set differently, but mine can. There are some switches to reverse the controls, and it's possible they got switched by accident, however unlikely.

I hope this helps!


- Sylvan

Kinmount Kid

I also have a J3 and I believe the advice from phase_boy is right. You have two jumpers on the board and one may have come off. The other thing you can look at is if the wires from the servos to the board may have come loose. Don't be afraid to dig around a bit and find out what is going on. I have had my plane apart a few times to do a few repairs and upgrades so I have gotten a little more bold about it now. It is all part of the sport. Good luck!
Bill

Reddog177

Sylvan,
If I'm not mistaken, that jumper is supposed to be removed after you gain some experience with flying the J-3. It's there to tone down the responses of the controls.
Dick

phase_boy

Dick,

You're probably right about that. I don't know what the Rx/Amp. looks like on the ParkZone model, though I know that if I remove the jumper from my Kyosho Cub's Rx/Amp., the controls become reversed.

My Cub is out of commission these days, until I find a new prop. shaft. I received a replacement Cub, finally, and went out and flew it in a little bit too much wind. I managed six or seven flights, but it was difficult to control. The motor did seem woefully inadequate when the wind picked up, and that was the cause of a few crashes. It ended up in a tree once, too. That was fun.

Kyosho doesn't sell just the prop. shaft; I would have to buy a new gear-reduction unit for a whopping 1500yen ($15 USD or so). I am trying to find a store that'll ship me three or four prop. shafts from North America, but it's proving extremely difficult. I know it won't be long before I'll need to replace the prop. shaft again, and I can't spend that much money each time. Until then, the plane is sitting in pieces on the floor. Kind of sad!

- Sylvan

Reddog177

Sylvan,
It sounds to me as if the jumper in your Kyosho may be a way to match it to different types of transmitters.
Maybe I can help you get your driveshafts. Could I order them over here and forward them to you? If so, contact me by e-mail.
Dick

phase_boy

Dick,

Yeah, I believe that is exactly what the jumper settings are for. Also, my Tx has a bank of five switches that do pretty much the same thing: reversing the controls, mixing, etc., presumably for different Rxs.

Would you happen to know the dimensions of the motor on your ParkZone Cub? Specifically, the length and diameter?
If I ever get this plane flying again, I'd definitely look into upgrading the motor - perhaps to a 370-class like in the ParkZone models. I found a 380-class motor in a hobby shop, but it was too big to fit in the gear-reduction unit. I guess the size of the motor-can doesn't necessarily decide the power output, but there is some relationship between them.


Thanks,

- Sylvan

bhpd1438

here's what i ended up doing. i took the guts out, stepped on them. then i took the guts out of an old megatech skyliner ep (piece of crap) after a few modifications i put them in the cub. everything seems to work now. i have not flown it yet, but i ran it through a pre-flight and everything worked. the electronics i put in are a bit heavier than the ones that come in the cub, i'll have to see if it flies now. I am getting a new cub in a few weeks anyway, but i did this just to hold me over. matt