Ragz

Yestreday, I lost my composite arf 3m extra 260 on its second flight. Approx four minutes into the flight, I executed a mild snap roll at half throttle. This resulted in a airplane entering into a failsafe and it never recovered. My setup was as absolutely top notch. I was running twin 8611 for the elevators and ailerons. The rudders had 3 8711's ganged with the swb floating bellcrank. The power system was controlled by the powerbox royal with TWIN futaba 6014 2.4ghz recievers. Everything was checked and double checked. The engine was programmed to quit if radio signal was lost. I was using an optical kill switch that was programmed to go off when radio signal was lost... needless to say it would go off, if reciever batteries also died. NOW the interesting part. For some reason I inserted an EMCOTEC DPSI BMS digital display just to monitor how much current the plane would consume per flight. This was in between the powerbox royal and the powerbox batteries...I am being told now, that the emcotec is rated for a max of 10amps only.. something I didnt know.. and should have known... I am assuming, the snap roll pulled up more than 10amps,, and shutdown the emcotec, which shut down the radio system completely... No other reason, why such a solid setup would lose radio contact... I dont know if the powerbox royal has a memory chip that records last flight, because its not showing up. Even the emcotec is not showing last flight data... I need to confirm if it was indeed an over current shut down.

Any comments? any suggestions? questions?

thanks in advance.

hanko

What are your battery specs? Im not familiar with what sounds like a complicated set up, but if you had two recievers, why did you lose the signal on both?

Ragz

hanko

well sorry about your loss guy, but unfortunatly you will probably never know why. My old friend Miles Reed who just passed always told me keep it simple.

Jake Ruddy

My Feedback: (40)

What batteries where you using and whats the voltage now?

If you lost everything then either the powerbox failed (doubt it), batteries came unplugged, or what you are thinking is correct.

Zeeb

My Feedback: (41)

Without more details on the power system, i.e. batteries specifically it's hard to speculate more than to say guys running airborne data transmission stuff like the Eagle Tree are reporting 35% size (smaller than your 3.0 size) pulling up to 12 amps during a snap.

Whether or not it was your PE shutting down is something others will have to answer/speculate on as I've never used those.

bubbagates

My Feedback: (32)

Since you lost complete control then something took power away to the point that it would not recover. Based on your description and the servos you used, I'd bet you overcame the 10amp limit and before it could recover, if it ever would recover it was too late. The other thing is that maybe the Royal and Emcotec overcame the limit but the receivers went into a reboot and never connected back to the transmitter. Also, and this is important when it comes to the Royal, did you set the Royal and Transmitter up to work together. There is a procedure you must do (called initialization) on a per channel basis and if you do not do that before you setup the servos on the Royal, you will have loads of issues.

Like others have mentioned, the batteries may not have been able to deliver the load.

My only question would be why did you use the Emcotec when the LCD screen that comes with the Royal will do everything you wanted to find out plus give you the load on a per servo basis (not history, just real time) and plugs directly into the Royal.

Actually I just looked up the specs for the emcotec (PER CHANNEL)

Max. continuous current per channel 10A (flow rate)
Max. peak current per channel (10ms) 30A (flow rate)

Something tells me you had some servos binding right from the beginning and as soon as you did the snap, you loaded the system to the point several things could not recover.

Just a suggestion, the next time just use the LCD screen that comes with the Royal. A few simple button pushes on the regular on/off switch and you can get loads of info and can easily be mounted to make it act like a dashpanel. Several places that sell them make extensions for the cable it uses so that you leave on end plugged into the Royal and the other end just connects to the screen, That way if you are mounting the screen in the Canopy, you do not have to try to reach into where the Royal is mounted, just unplug the extension from the screen.

BTW, the Royals do fail, I had one that was not holding it's setting on a single channel (adjustable channel A), I cooked 6 8611's in two days. Everything was fine until I shut the plane off for more than an hour, then all setting would go away for that channel. The second day we sat at the field and replaced the servos, we checked, checked and checked some more and everything was fine and I have configured quite a few of Powerbox products for people, I did 3 flights back to back then sat for an hour or so. Got up, fueled up, turned everything on and by the time I walked to the front of the plane from the side to start the engine, the same channel had already cooked the servos. (you know it's bad when smoke is coming from the root of the wing). Sent the unit back, they found the EEPROM was faulty as well as one regulator. They replaced it, sent it back,, it worked fine up until I sold the plane it was in, I know it's still in use today

Ragz

Hello,

THe batteries used were powerbox 2800ma li-pos.  One got badly damaged on impact, the other seems to be dead (for some reason), however the case has a mild crack on it.  Needless to say, all the data on the royal is lost upon impact, so I will never know what really happened in it.  I spoke with Emmerich from powerbox, and he has asked me to send over the entire power system for a checkup. 

I installed the DPSI BMS only becuase it has a very convenient memory feature.  It keeps previous flight data even after power off.  Since this was a new airplane, I wanted to get an idea about power consumption etc.  The BMS was meant to stay in the plane for a few flights only.

I setup the royal and recievers as per the manual.  I dont know of any channel by channel initialization thats mentioned in the manual.  If you mean initialization of end points with the adjustor board, then they were done.  Fail safe was setup exactly as per manual, and it was working as I was able to simulate a failsafe on the ground by removing the failsafe wire from the failsafe connector hole.  The manual mentions this as a test anyway.

I was reading the manual for the emcotec dpsi bms.  This mentions that the start up current needed is 150ma and if the system detects currents less than 150ma, it SHUTS DOWN.  There is one theory that suggests, (some electrical expert told me this) when an electric motor suddenly stops, it pushes back some juice back into the power supply... and this maybe the reason the bms turned itself off???  I find that implausible.. but I am not expert to comment beyond this.  My setup had the bms BETWEEN the batteries and the royal... so essentially, the bms was acting as a switch for the royal. 

Upon snap roll, the engine shut down (failsafe feature) and all controls were lost.  The optical kill swtich was setup so that it would turn itself off upon loss of signal or loss of power.  I will never find out what happened?  Signal was lost or power was lost!!!!!!  I am inclined to the power loss theory, because two new 6014's failing together is really unbelievable...

Now, the interesting part:  Upon connecting a different battery to the emcotec, the current readings are unbelievable... max current is (<0.30 amps) and average current is (<0.15amps).  How can this be?  Does this ratify the reverse EMI (or wahtever its called) theory?

thanks

PTS

My Feedback: (153)

Did you buy all the parts new? Ahhhh the horror stories...

PTS

My Feedback: (153)

How much experience do you have with Li Po's? Do you know for a fact that they were completely charged? Did you use a current meter to see if the servos were binding during build/setup?

Ragz

Brand new part... and batteries were fully charged... confirmed that...

Ragz

I have enough experience with setting up ganged servos... I know for a fact there was minimal binding.. as there can never be zero binding... the powerbox adjustor board works well.. and i have used an ammmeter inline along with the pb royals display board to ensure that the currents were lowest before locking down the center and extreme postions of the ganged servos... in a nutshell, i do know that the setup was absolutely rock solid... there was one weak link.. and that failed... and im more and more inclined towards believing that the emcotec bms failed.

PTS

My Feedback: (153)

Call Duralite Batteries and speak to Jack. He might be able to shed some light on the incident.

Ragz

Thanks I am already in touch with Mr. Emmerich Deutsch, owner of powerbox regarding this issue.

bubbagates

My Feedback: (32)

Yea, he's a really good guy. I had the royal do some funky things on channel A as I explained below. Sent it back to him, got it back after they replaced the EEPROM and all is well now.

I did mean channel by channel initialization and it's done at the same time as doing the end-points. I'm wondering if you had the same problem I did. It just took a bit longer to happen. One thing I failed to mention that happened with mine is when it locked up on channel A, the batteries would be drained really really fast but not before the wires would start to melt going out to the servos. I would try to power up the Royal and see if the settings are still there and the servos are moving exactly as you set them. I had to actually hook up spare servos to each channel in the same plug locations on the Royal to find the problem. The settings looked fine but once I had the servos on channel A and I would move the stick, they would go in opposite directions. Damndest thing I ever saw.

Would I still use a Powerbox, yep, I just ordered the 12 channel one for my next project. As I mentioned, I've setup tons of different PB's for others. They are pretty straight forward. The only thing is if you change radios, then you have to go through the whole initialization process again. I do not use their batts though, I like having 10,000+ milliamps on board for the receiver so I use 5200MaH Fromeco's

crazyjoseph

My Feedback: (3)

If after sending power box in they find nothing then my guess would be that the batt you found to be dead after the crash was dead before the crash.

mrbigg

My Feedback: (21)

Wow, I'd be bummed.[:@]

custards1

What i dont understand is what was the point in running duel receivers if its all running back thought 1 power system? I know it was duel battery's but surly the idea is to have 2 separate systems to try and avoid what happened? a single point power failure brought the plane down even though it was meant to stop it

Ragz

the powerbox royal and any other powerbox is essentially a twin power system.. everything inside is dual...

Ragz

Just discovered that one of the powerbox 2800ma 7.4v battery is totally dead.  The other one was destroyed in the crash.  Can a battery just die on impact? Its not showing any reading on a voltmeter.. The case has a mild crack on it, but all the wires are fine.  I will open up the case and recheck.

crazyjoseph

My Feedback: (3)

Many think they have a redundant battery set up but with the power consumption of some of these new JR servos can there system really keep up if one battery goes down.

kochj

Cut it open and look at the direct battery conection.. see if all is connected....
THen check each cell (just place you watchamacollit voltage meter with some charge wires, and
use the charge connection ends to touch the battery wires)

Even if one is dead, what about the other battery, the one that was distroyed???
Just because it has holes in it, doesn't mean it doesn't still have some charge left in it...
This would have to be done right away after the crash....

Use the components (power box, voltage meter, ect) and plugg all servos in, and start running them ALL
at the same time , and see what happens.....

I had reduced attena reception, never ever happened prior (had many flights with the same radio system)
Turns out it was a Votage regulator that was causing this....

ALso,,,
Did you preform a EXTENSIVE RANGE CHECK prior to your first flight??????
This coud have discovered a issues...before flght took place.

Verbeelding

Hoi Ragz,

did you use the futaba 6014fs OR hs ?
because they have an issue about the hs receiver in hs mode.


greetz
P

davensocal

My Feedback: (1)

Nothing like resurrecting an old thread with a dumb question..

The Emcotec BMS doesn't have a switch function, and is advertised as not having the ability to interrupt the power to the system.

In previous posts, it was mentioned that the Emcotect BMS will shutdown when the current is less than ~100mA. The docs I have read say the same, but add that it needs to have that low current for more than 10 seconds. Even after this has occurred with the BMS system, it still doesn't affect flow of power, it just turns off measuring device. The BMS is never supposed to be able to control power.

Are we somehow confusing this with the Emcotec BIC? The BIC has switch functions, but it doesn't have the auto off feature (for obvious reasons)..

Sorry, just a little confused. I was looking at putting a BMS into my next plane.

Magne

Hi.
This does not tie up at all.
The original poster said the plane went into a failsafe situation, in which case the crash was NOT caused by a power loss.
Radios don't go into failsafe without power, they stop working. Different things altogether.

Magne