2.4 Ghz lockout/glitch

[strat1960s]

I have a DX6. I was practicing hovering Thursday when my heli throttled up, flew about 60 feet and then crashed. So what causes a glitch free system to lock-out/glitch? I've seen video and heard stories of systems locking out at the most in-opertune moments. I had all the replacement parts needed to repair everything, but what caused it to lock me out/glitch and crash? I re-binded the TX/RX this afternoon. When the heli was set up for me I think the idle was set to climb instead of hover or descend. I set the throttle to descend slowly (slightly less than 50%). How often do I need to re-bind the tx/rx?

Ted

[jlasater]

fwiw...Should not have to rebind...
DX system will reboot if the voltage drops below 3.5 V. Be sure your bec/esc is up to the task...How was the range check before the flight?

John.

[strat1960s]

Everything was working fine right up to the moment I was locked out. I was only 2 or 3 minutes into my flight/hover when it happened. I can see (the heli's altitude drops) and hear (the motor sound pitch changes) when the lipo is getting low. That's usually when I power down and grab another lipo pack. Seems like everything is pointing back to the BEC.

Ted

[Coolice]

Hey,

Just a small observation but for safety the failsafe should be set to power down the motor totally, so if the model does head towards someone it's not doing so with power.

Just an idea on the lockout with 2.4ghz, bear in mind I do not fly it yet due to reading about these lockout issues still but it could be a power/reboot issue.
What problem I do see regularly is that if the main Rx. supply voltage drops too low then the receiver will reboot, hence lockout. To get over this in the IC models people are fitting high power supply systems, also there is a plug in capacitor which plugs into a spare Rx. channel. This capacitor then acts as a small amount of backup/smoothing power supply incase of a large power spike dropping the voltage supply to the receiver, hence preventing the rebooting issue.

Here : http://www.helifreak.com/showthread.php?t=54836 is a similar issue regarding 2.4ghz and power supply induced lockouts/rebooting. Worth a read perhaps.
.

[strat1960s]

Coolice,

I did not know that was supposed to be set to zero. Thank you for the heads up. So far, most of the folks that have responded to my posts (other forums included) think the problem may be in my BEC. I'm really leaning towards a new BEC even if it's not determined to be the cause of the lockout condition.
Thanks again for the heads up. I'll re-bind at zero throttle tomorrow morning.

Ted

[strat1960s]

coolice.

I read through my manual this morning prior to re-binding the tx to the rx. It said in the manual to set the throttle level to a low level not zero. So I went ahead and set the throttle to zero and re-bound it. I hope I don't run into any problems when flying over a highway or a lawn mower.:YeaBaby: LOL
I was thinking I would rather have the heli descend slowly as apposed to drop like a rock. However your point about it possibly heading towards people convinced me that zero was the setting to go with.
Thank you for the heads up.

Ted

[Coolice]

Hi Ted,

I know exactly how you feel mate about not wanting the heli to fall like a brick with no power, but in the UK for instance it is mandatory (especially at shows etc.) to have your failsafe set to kill the engine/motor.
From a safety point of view it's best to cut power, also if the model comes down still in fail safe it wont thrash itself when it's on the deck.
It's a catch 22 situation really as in failsafe your not in control of the model anyway and so it risks crashing anyway.

A little trick that I now use is to setup throttle hold the kill the power as normal and hit the hold switch, then put the collective stick to 0 degree's, then set the failsafe. This way the motor dies but the main blades go to 0 degree's pitch which inturn wont make the model go up or down if failsafe cuts in.
Also in most case the model will carry on floating for long enough for control to come back and the pilot to safely land.

Your problem could be BEC related, in the previous 2.4ghz lockouts I have read about which centres around power delivery, if your BEC is struggling to supply enough current to power your entire radio system then this could be it. With all servo's moving current draw goes up, the BEC then struggles to supply enough amps and the receiver see's a power drop and hence locks out.

It will be interesting to hear what you find when you change your BEC.
.

[strat1960s]

COOLICE,

Well, I put the new BEC/ESC in and guess what?? The sucker is running hot! I went with the Common Sense 35A model. I haven't flown it yet, just a bench/desk test. I spun it up to less than 50% throttle and the heat sink was screaming hot just after a minute. I'm pretty sure it's wired up properly. The blades are all spinning in the proper direction (clockwise) and the servos all seem to work fine.
This makes me more than a little nervous. The BEC/ESC high temps was the reason why I switched to begin with. ARGH!
I'm waiting to hear from the folks at Common Sense to see what to do next. The one thing I'm noticing is that very few manufactures include detailed instructions and troubleshooting tips. Double ARGH!!

I'm in Texas now, on my way to a 2 month long class. I've driven over 1600 miles in the last 2 1/2 days. I've seen some really nice places to just pull over on the side of the road and fly. Since I was in a hurry to get where I was going I didn't stop. I have another four hours of driving this morning. If it's not raining and not too windy, I may put on a set of rotor blades and give outdoor flying a try. I've been flying this whole time inside an aircraft hangar. Heated, well lit and no wind to speak of. Yes, I was spoiled.

Ted

[Coolice]

Hi Ted,

Ah your making me jealous now mate, I'd love to have access to a large indoor hanger to fly within. In the Uk at the moment the weather isn't very favourable and so we're having to make do at the local indoor events to atleast have a fly.

Oooh, even with a new ESC it's still getting very hot by the sounds of it? This is most likely been your problem and in turn causing the ESC to shut down power to the receiver. The question is why though as while the ESC & motors temperature should elevate slightly, you should be able to put your finger on both and not pull it away due to being burned.

There are some other things then now to maybe look into :

1. What throttle curves are you flying? Really and truly I am trying to find out if perhaps you maye be running them too low, you may know but I will mention it anway that you should be running your ESC at all times above 80% power. If not then the excess voltage has to be used up in some way and this is done by the FET's which in turn get hot and could fail.

2. Your motor mounting screws, are they too long and shorting inside the motor onto the windings?
Silly question I know but I have had this myself when building my Swift initially and choosing to long a screw to mount the motor with. Luckily I figured out why the motor was getting to hot before I even flew it.

3. The actual motor your using, it's not uncommon for them to fail but not out right enough for them to stop totally. In most cases a winding can come loose inside the motor which then shorts out on the casing or elsewhere, then if you put power through it via the ESC this will then get hotter than normal due to the shorting.

Some more ideas to consider perhaps.

Have a safe trip buddy.

Ian
.

[strat1960s]

Ian,

The weather here in Texas is pretty nice. I haven't flown yet.
Mechanically everything seems fine. I think it may be the BEC/ESC. I wander if I should be using a 45 Amp BEC/ESC instead of the 35 Amp. I'll ask around on a couple of the other forums and see what I find out.
Take care and stay warm.
PS. It's negative 7 back home and they got over a foot of snow. Glad I'm in Texas.:YeaBaby:

Ted