J3 Cub not responding to the transmitter.

[CHEVELLESS]

My brushless j3 cub bl by parkzone crashed because the wings buckled in a loop. well the when i plug in the battery the servos twitch and the plane beeps like its supposed to and the transmitter turns on like its supposed to but the plane wont respond to the transmitter. I replaced the receiver and still didnt work and I also tried swapping the crystals and still wont respond. Do yal think its the ESC? I dont know what to do. Thanks for your responses.

[flydiver]

Stalled prop on crash with the power probably still on > fries the ESC in seconds. Creates a dead short across the motor.
Common new flier mistake. Got to turn that power off instantly.

[CHEVELLESS]

ahhh ok that makes since. the throttle on the controller is sideways and when the wings buckled I was trying to pull the throttle back instead of pushing it to the left because im used to my brothers dx7

[CHEVELLESS]

so is the motor still good or just replace the ESC?

[flydiver]

Motor is probably good. Only way to tell for sure it put it on a new ESC.
DO NOT do a direct short across a battery! That only works for BRUSHED motors.

If the motor does not run properly and immediately > STOP!
A motor that jerks around and won't run indicates a bad connection on one of the 3 phases (solder joint bad, broken wire, etc.) That ALSO is a dead short and will fry the new ESC.

After a crash you need to always suspect there is more wrong than it appears.

IMPORTANT EDIT - just looked at the PZ J3 parts page.
That page shows BOTH a 10A ESC.....AND a ESC/RX package. It shows no separate RX alone.
You said you replaced the RX??
Plus you NEED to have the RX and TX on the SAME channel frequency. You can't just swap Xtals around randomly.

Does your plane have a separate RX and ESC?

[kyleservicetech]

Originally Posted by CHEVELLESS

My brushless j3 cub bl by parkzone crashed because the wings buckled in a loop. well the when i plug in the battery the servos twitch and the plane beeps like its supposed to and the transmitter turns on like its supposed to but the plane wont respond to the transmitter. I replaced the receiver and still didnt work and I also tried swapping the crystals and still wont respond. Do yal think its the ESC? I dont know what to do. Thanks for your responses.

Take a look:
Drytesting brushless motors
http://www.wattflyer.com/forums/showthread.php?t=35216


Also, if you've got a digital voltmeter, check the voltage on the red and black wires of the ESC cable that connects to the receiver's throttle connection. That should be 5.0 Volts DC.


Digital Multimeters, How to use them
http://www.wattflyer.com/forums/showthread.php?t=52821

If you're using the same crystal in the new receiver from the one that crashed, could be the crystal got damaged.

[CHEVELLESS]

so.. here is my cub with the guts pulled out. I bought a separate replacement receiver (on the bed in the pic) the new receiver is CH4 FM27.145M just like the transmitter. The planes throttle was not cut off before it hit the grass and broke the prop. I am going to order a new ESC and see what happens. Im glad I wrecked so now im getting a chance to figure out all this electronic stuff.

[flydiver]

Appears there is a separate RX and ESC.
The ESC must be plugged into the correct channel (probably 1) and it must be the correct way, same color order as the servos. Being in backwards won't hurt, just won't work. There may be a diagram on the side > - + and a thing that looks like a top hat.
- = black, brown or darkest wire
+ = most always red in the middle
top hat = white, orange, yellow or lightest wire which is the signal wire for the ESC. This allows it to figure out which direction and how fast to turn.

Don't you just love the standardization?

RX seldom get damaged, but the Xtal can take a hit or fall out in a crash.
ESC get fried all the time.
Motors are fairly robust as long as not overpropped and fried (pretty common), direct crash damage (very common), or wires broken (not unusual) from handling or crashes.

[CHEVELLESS]

They are all plugged in correct. Hopefully a new ESC will get it back up in the air!

[CHEVELLESS]

so now i replaces the reciever and esc and it still beeps and the servos twitch and the plane wont respond to the transmitter. the transmitter is fine and has never been droped or anything and all the parts i got are direct replacements. i dont understand

[Gohmer]

Try this sequence. New TX batteries, TX on, antenna fully extended, throttle and throttle trim at zero, plug in fully charged flight battery.

[CHEVELLESS]

Originally Posted by Gohmer

Try this sequence. New TX batteries, TX on, antenna fully extended, throttle and throttle trim at zero, plug in fully charged flight battery.

Thanks for your reply! and I have done that. so any more suggestions?

[CHEVELLESS]

Originally Posted by Gohmer

If your TX has servo reversing make sure the throttle didn't get reversed.

You can send it to me and I'll fix it and send it back if you make me a knife like your first one

Yea, I checked those switches too. That knife was my senior project in high-school haha. My Dad is a big custom knife maker in all the guilds and stuff and he told me how to do it but never put his hands on it. It was fun. I might make another this summer.