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Old Mar 07, 2011, 02:14 PM
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Vienna, Austria
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If there was a brownout, the led would blink. After my crash the led was solid. At least all my models (and most other models talked here about) were flying with my DX6i (or other radios before) flawlessly, and a new radio will not cause brownouts from one moment to another.

My DX8 arrived today at HH Germany. I hopefully get it back till thursday, our indoor flying day. And I will test it througly before I use it on my helis...
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Old Mar 07, 2011, 04:06 PM
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USA, AZ, Phoenix
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Why does the plane need to be in the air to reproduce the problem, if it is not related to servo loading or tx, rx antenna issues. I would think you should be able to pretend to fly the plane and it should fail. I had a wire inside a servo get loose in a plane and that made the plane do strange things until it crashed, the plane was a foam flying wing so just two servos. The one that went bad would go full up and put the plane in a fast roll.
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Old Mar 07, 2011, 04:39 PM
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Australia, VIC, Cranbourne East
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Originally Posted by freechip View Post
Here's what CC has to say about it in regards to their 20A CC Bec Pro
In practise even that advice is not always right ,for example a AR610 of mine under the plug strip there are fine bus rails on the circuit board connecting the positive pins together as common and also the negatives ,those fine circuit board tracks can burn or go open circuit as it happened to me (servos tested fine), a better system is for all the positive and negatives be joined together as seperate positive and negative external from the RX and only the signal pins on the RX used for servo connection, use for seperate flight pack installations.
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Old Mar 07, 2011, 04:51 PM
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Originally Posted by Kambalunga View Post
Wrong assumption again!
DX7se, DX7 and DX6i all clean DSM2 but different latency.
Then is not the RX your problem, with a lower latency increased your servo power demand.

http://rc.runryder.com/helicopter/rr...?p=1310272&i=2
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Originally Posted by aerocal View Post
Carlo
I know at first glance it doesn't seem to make sense but think about it a bit more.
Ive heard many different explanations as to why this occurs.But what he is saying is exactly what I have noticed happens to be true.In my case the differences between my DX7 and DX8 werent alot different.But it was enough to see that DX8 does use power differently and in general just a little bit more of it.I almost got sucked into going farther to try to figure out why.Too much like school then.I just want to fly and have fun not argue about why something is the way it is.Apply a little basic logic...Get some basic test equipment setup your plane making sure it has enough voltage at the Rx and go fly it.This is true for any combination of equipment not just the DX8.
I still say that all other things equal the DX8 is a bit more demanding to the Rx/servo power.A model that may have been running marginally with no obvious issue like it stops working and crashes could very possibly be pushed over the edge being used with a different Tx.Thats my story and Im sticking to it.
Considering this information is correct, the differences in power consumption would be so marginal that I don't think this would be the root cause of the issue.
It would make more sense if issues occured because of the 11ms frame rate. Most of the occurances that have happened, recently, were on 22ms rx's.
I've used an oscilloscope to look a the frame rate on the AR7000 and AR6115, using the DX7 and DX8 (DSM2 and DSMX modes). In a side by side comparison, they are nearly identical.

I've also done several tests, with the DX7 and DX8, monitoring the BEC voltage with a multimeter. I've gone below 9 volts (3 cell flight pack) wot and random servo movements at full deflection. My BEC voltage has never dropped below 5.04 volts.

For the majority of those experiencing random loss of power/signal, I don't think this is the issue.
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Old Mar 07, 2011, 05:17 PM
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Originally Posted by cayars View Post
Yes I know the typical servo type connector is rated at 5amp max but you'll find plenty pushing this. It's quite easy to pull more then 5 amps through them. Just get a small light bulb and connect it up through an extension and you'll see it can do 10 amps pretty easy even with the thinnest of wire. The receivers themselves can handle 10 amps (I believe that's the number).

On all but my small foamies I usually plug my ubecs into multiple ports. Just an old habbit from many years back. On larger bird I always run multiple radios with the aircraft set up with one radio for the left side of the plane and one for the right side of the plane. Cheap insurance in my mind.

But yes I do agree you need to know how much your servos are pulling under stress at the same time and how much power you are really getting to them.

But with that said I don't think this has anything to do with the brownout I can reproduce on the foamy with the DX8/6200s. 10 Amp UBEC or battery pack and 3 micro servos. It's flipped out in a gentle banked turn. The servos probably aren't anywhere near 1.5 draw let alone close to 5 amp.
The rx BUSS are not all the same and the ratings are for total current The best rx leads will handle 4 amps at 6.6 volts and the sh-it from Hobby King will not do this!
This is not a guess- it is info I got from using two A123 2300 ma cells (the best rx packs available ) and two 1157 light pulbs with all elements running bulbs in parallel
the draw is actually 3.75 amps as shown
add one more bulb in parallel and watch many connectors soften and melt
INSTANT draw can exceed this but a steady draw will soften and melt most connectors and also some of th e gypo wiring .
The packs as shown hold 6.6 down to 6.3 v in 30 minutes then quit.
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Old Mar 08, 2011, 01:19 AM
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Deutschland, Hessen, LA
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Originally Posted by Confuzshuz View Post
Considering this information is correct, the differences in power consumption would be so marginal that I don't think this would be the root cause of the issue.
It would make more sense if issues occured because of the 11ms frame rate. Most of the occurances that have happened, recently, were on 22ms rx's.
I've used an oscilloscope to look a the frame rate on the AR7000 and AR6115, using the DX7 and DX8 (DSM2 and DSMX modes). In a side by side comparison, they are nearly identical.

I've also done several tests, with the DX7 and DX8, monitoring the BEC voltage with a multimeter. I've gone below 9 volts (3 cell flight pack) wot and random servo movements at full deflection. My BEC voltage has never dropped below 5.04 volts.

For the majority of those experiencing random loss of power/signal, I don't think this is the issue.
How fast is your multimeter?
I suggest use an oscilloscope.
What happen at a FBL system when the gyro has a reboot caused by a voltage drop?
You crashed then.
The the question is why used he not the recommend auxiliary akku?

http://www.rc-heli.de/board/showthre...96#post1470796
http://www.rc-heli.de/board/showpost...3&postcount=23

This heli pilot crashed two times with the Kobby.
He read the diagnosis code BEC overheated.
Kontronik says its was a EMK problem.
Its not always Spektrum that caused the problem.
Then is the 3g gyro notorious for tail wag and sporadic tail kicks.


Then speak you about a BEC or SBEC?

Then is framerate and latency not the same!
The Spektrum DX7 with AR7000 has 15-40ms latency but a DX6i with the same RX has 22-50ms latency.
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Old Mar 08, 2011, 02:08 AM
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Vienna, Austria
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The 3G is most tolerant to voltage drops. It works down to 2V (although the servos do not operate this low, the system stays initialized). And my crash has nothing to do with tail wag or kicks. The heli was flying a straight line constantly descending into ground
As for the backup battery, Kontronik recommeds it for every ESC they sell. Just to be on the safe side. Nevertheless most pilots do not use a battery pack. I am using some green caps for buffering in my 550. Have you ever seen a 450 with battery pack ?

Also, I encountered a blinking LED on a 6100 on my T-rex 250. With no jumps, kicks, just during hovering 2m in front of me, the LED suddenly started blinking. No other effects. That's also very uncommon...
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Old Mar 08, 2011, 02:21 AM
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Deutschland, Hessen, LA
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What is about ESD?
T500 Static Charge Vid (0 min 52 sec)


Protos Static (to fix ground to Neg Lead!) (2 min 24 sec)
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Old Mar 08, 2011, 05:37 AM
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Torque tube (modded my 450 sport with align TT upgrade).

I also had an encounter with my 250 on the ground. just flicked the switch for gyro sensitivity (hh/non hh) and suddenly the RX (6100) started blinking. No motor, no servo movement. Just flicking gyro switch.....

I apprechiate your efforts, but unfortunately all these possibilities have been sorted out. And, as mentioned before, I had lots of flights with all of my helis before. I am the last to blame my DX8 for any issues, because I love it. But unfortunately all other options have been sorted out. Let's see what the Germans at HH are doing to my beloved radio
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Old Mar 08, 2011, 08:29 AM
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Australia
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Originally Posted by Victory Pete View Post
Wondering if every flight is your last and losing planes is kind of annoying!
VP
Thanks Pete. Sounds like we are having the same concerns.
I guess if the other guys were having the same serious issues they would be a bit more apprehensive too. Half their luck.
Ive had real problems with the DX8 from day one. Not just silly personal issues but real faulty equipment issues.

Quote:
Originally Posted by aerocal View Post
Ths really serves no useful purpose.Honestly it is kind of annoying as well.
Your dismisal is quite annoying to me as well. Thats the newage attitude i guess. If you were having issues like me and others it would annoy you to, again, half your luck.

I am at the point were i can fly the DX8 with my heart in my mouth....
Ive had one random brownout since i replaced a suspected faulty AR7600 with AR8000 but its still unexplained as the telemetry didn't tell me anything but the RX was flashing...waiting for HH to send me AR7600 relacement.
It was assigned to technician and three seconds later, ready to ship. I will hopefully get more info on that as it worked with DX7SE
Ive had one random crash too, just dropped with a left and down.....from what i read thats the same as the suspect AR6200 and AR6100 problems.

Honestly I just dont feel its reliable. It really annoys me that its this way.
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Old Mar 09, 2011, 12:06 AM
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Bridgeton, NJ
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Managed to get out to the field today. Flew 2 more 6200s (different then first ones) and didn't experience any loss of control with either of these but they were blinking when I landed. (still don't like that). I only got 2 flights on each one but this is better then I was able to do with the previous 6200s.

So I'm 2 for 5 with the 6200s thus far.
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Old Mar 09, 2011, 01:45 AM
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Originally Posted by cayars View Post
Managed to get out to the field today. Flew 2 more 6200s (different then first ones) and didn't experience any loss of control with either of these but they were blinking when I landed. (still don't like that). I only got 2 flights on each one but this is better then I was able to do with the previous 6200s.

So I'm 2 for 5 with the 6200s thus far.
Blinking is a bad sign.The thing to do now is borrow a datalogger and plug that sucker in for the next flight.This is the rare opportunity to either confirm or debunk the brownout detection in your specific case.
Better yet put a TM1000 or 1100 in it.One way or the other determine what the PeakLowVoltage actually is.That may not be the actual issue but you have to start somewhere and rule out a power supply problem.
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Old Mar 09, 2011, 03:24 AM
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I find it's something funny with the Dx8. We have two novelties : telemetry and DSMx. And with these new things nobody has a problem, it's totally perfect. The problems for some people are with knews things or with old's reveivers. Strange isn't it ?
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Old Mar 09, 2011, 04:01 AM
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Australia
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Originally Posted by aerocal View Post
Blinking is a bad sign.The thing to do now is borrow a datalogger and plug that sucker in for the next flight.This is the rare opportunity to either confirm or debunk the brownout detection in your specific case.
Better yet put a TM1000 or 1100 in it.One way or the other determine what the PeakLowVoltage actually is.That may not be the actual issue but you have to start somewhere and rule out a power supply problem.
I found that the TM1000 telemetry doesn't update that quick and can miss the brownout (does with mine) a good meter with min/max is better/more accurate.

But the AR6200 doesn't have a data port so a meter is his only option.
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Old Mar 09, 2011, 04:05 AM
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Australia
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Originally Posted by furien View Post
I find it's something funny with the Dx8. We have two novelties : telemetry and DSMx. And with these new things nobody has a problem, it's totally perfect. The problems for some people are with knews things or with old's reveivers. Strange isn't it ?
The telemetry is far from perfect yet. There is still bugs.

Try disconnecting the power to Rx and does the telemetry alarm...no It only works if you lower the voltage slowly....Now with DSMX and no brownout detection i would say that feature is important for power issues.
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