Go Pro camera + spectrum 2.4= failsafe.
01-24-2011 | 01:04 PM
#26
RE: Go Pro camera + spectrum 2.4= failsafe.
ORIGINAL: BaldEagel
Genuine A123's are only made in 1100Mah and 2300Mah are you sure he had A123's and not copies of some sort, also I did read the first post and he had two what he says are 1200Mah batteries therefore he had 2400Mah on board, the likelyhood of a battery failier with genuine A123's is very remote, I know of no known failiers of genuine A123's without some kind of abuse being involved.
Mike
Genuine A123's are only made in 1100Mah and 2300Mah are you sure he had A123's and not copies of some sort, also I did read the first post and he had two what he says are 1200Mah batteries therefore he had 2400Mah on board, the likelyhood of a battery failier with genuine A123's is very remote, I know of no known failiers of genuine A123's without some kind of abuse being involved.
Mike
01-24-2011 | 01:27 PM
#27
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From: wilmington, DE
RE: Go Pro camera + spectrum 2.4= failsafe.
I have used the GOPRO on several planes without any incident whatsoever!
Before my first flight Idid a thorough range check (using FASST)and it was the
same as without the camera
SEE>>> http://www.youtube.com/watch?v=OCmfvkevTyw
This is a really great camera!
Before my first flight Idid a thorough range check (using FASST)and it was the
same as without the camera
SEE>>> http://www.youtube.com/watch?v=OCmfvkevTyw
This is a really great camera!
01-24-2011 | 01:28 PM
#28
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From: San Jose,
CA
RE: Go Pro camera + spectrum 2.4= failsafe.
Looks like the batteries were undersized to me. With all the gear on that plane one pull-down in voltage would send the plane into "failsafe mode" and lockout the controls. Sounds like the tubine went to idle and all the other controls to the default settings.
If you get 3-4 amps on one of those batteries you could see this type of drop in voltage. That could occur if all the servos operate at the same time. This can happen a lot when people use the higher torque servos used for mechanical retracts like the JR-791 servo.
Jeff
If you get 3-4 amps on one of those batteries you could see this type of drop in voltage. That could occur if all the servos operate at the same time. This can happen a lot when people use the higher torque servos used for mechanical retracts like the JR-791 servo.
Jeff
01-24-2011 | 02:15 PM
#29
RE: Go Pro camera + spectrum 2.4= failsafe.
ORIGINAL: Robrow
Hey Stalle do you have any pics of your external camera install?
Hey Stalle do you have any pics of your external camera install?
Here is a few pics of the two mounts I have installed.
I normally fly with the camera in the cockpit when facing forward. Looks more realistic I think.
Looking forward to the next video from the cockpit with the panel and pilots in place.
Here is one video from the cockpit.
[youtube]http://www.youtube.com/watch?v=QEM05WGeTs8[/youtube]
01-24-2011 | 05:59 PM
#30
Senior Member
RE: Go Pro camera + spectrum 2.4= failsafe.
Even if the camera does not itself transmit RF as a function, it's theoretically possible that it could be emitting RF interference, but it would really be a fluke if it was.
Look at all the interference emitted by a modern computer or any other electronic device, esp. if you take the metal case off; if you got a dud camera ie. let's say the switching power supply needed a metal shield in order to get a pass from the FCC, and that metal shield ended up being left out or poorly installed in your particular camera, causing it to emit enough RF interference in the 2.4GHz band. Theoretically possible, can't really be tested unless you had a spectrum analyzer at the time (even if the camera still operates, the crash could have changed its properties), and all things considered, it's probably one of the least likely scenarios for why the plane crashed.
Look at all the interference emitted by a modern computer or any other electronic device, esp. if you take the metal case off; if you got a dud camera ie. let's say the switching power supply needed a metal shield in order to get a pass from the FCC, and that metal shield ended up being left out or poorly installed in your particular camera, causing it to emit enough RF interference in the 2.4GHz band. Theoretically possible, can't really be tested unless you had a spectrum analyzer at the time (even if the camera still operates, the crash could have changed its properties), and all things considered, it's probably one of the least likely scenarios for why the plane crashed.
01-24-2011 | 07:25 PM
#31
My Feedback: (67)
RE: Go Pro camera + spectrum 2.4= failsafe.
I have a few questions regarding the A123 with JR1222 setup.
1. Will a shorted battery drain the other good battery in a JR1222 receivers if they are hooked up directly to the receiver?
2. Will the 6.6V power supply damage JR8411, 8711 circuits and cause a short circuit?
here is the link to the JR1222 RX info.
http://www.horizonhobby.com/Products...222#quickSpecs
Thanks,
Mike
1. Will a shorted battery drain the other good battery in a JR1222 receivers if they are hooked up directly to the receiver?
2. Will the 6.6V power supply damage JR8411, 8711 circuits and cause a short circuit?
here is the link to the JR1222 RX info.
http://www.horizonhobby.com/Products...222#quickSpecs
Thanks,
Mike
01-24-2011 | 11:58 PM
#32
RE: Go Pro camera + spectrum 2.4= failsafe.
Here are some pics of the toasted gopro HD camera... Its amazing how well made it is as the SD card survived such high temps... can post more pics if someone wants to see 
01-25-2011 | 12:46 AM
#33
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From: Paris, FRANCE
RE: Go Pro camera + spectrum 2.4= failsafe.
ORIGINAL: rhklenke
Again, if you listen to the video, I do not think that the RX batteries died because the turbine keeps running. It sounded to me like the airplane when into failsafe and the owner had not set the failsafe on the engine to shut it down - only to bring it to idle. Am I missing something here?
Bob
Again, if you listen to the video, I do not think that the RX batteries died because the turbine keeps running. It sounded to me like the airplane when into failsafe and the owner had not set the failsafe on the engine to shut it down - only to bring it to idle. Am I missing something here?
Bob
ECU (and turbine) is powered by his own battery. If the receiver is shutted down by a loss of power, the ECU is still running with his own accu but detect the loss of the receiver => go to fail-safe mode.
Don't know this particular ECU, but with Jetcat ECU, a loss of signal don't come to a instant shut-off of the engine. When ther's a loss of signal, the ECU down the turbine to idle. If signal has not come "on" in the future 2 or 3 seconds, then the ECU shut-off the turbine immediately. (This is a way to permit recovery of the plane if loss of signal what temporaly)
On this video, it seems there's a loss of signal or of power : the engine go down to iddle and the other command seem's to be in "hold" mode and frozen. The pilot ordered a slight left rool for a turn when signal was lost, and the model continue to rool constantly. Then there is no more than 2 or 3seconds before the model crash, so it's not abnormal for me that the engine was still idle when it hit the ground.
A sad crash, and the video is very impressive.
But this is not enough to say if it was a loss of power (servos are frozen where they are with no more movement), or a loss of signal between transmiter and receiver with receiver going in "hold" fail-safe mode. We need to know how were the settings of the fail-safe, and how work the ECU when it goes to fail-safe.
Regards.
01-25-2011 | 03:36 AM
#35
Senior Member
RE: Go Pro camera + spectrum 2.4= failsafe.
ORIGINAL: olnico
That's just another Spektrum lockout event.
That's just another Spektrum lockout event.
<br type="_moz" />
01-25-2011 | 04:45 AM
#36
My Feedback: (24)
RE: Go Pro camera + spectrum 2.4= failsafe.
ORIGINAL: Nhalyn
ECU (and turbine) is powered by his own battery. If the receiver is shutted down by a loss of power, the ECU is still running with his own accu but detect the loss of the receiver => go to fail-safe mode.
Don't know this particular ECU, but with Jetcat ECU, a loss of signal don't come to a instant shut-off of the engine. When ther's a loss of signal, the ECU down the turbine to idle. If signal has not come ''on'' in the future 2 or 3 seconds, then the ECU shut-off the turbine immediately. (This is a way to permit recovery of the plane if loss of signal what temporaly)
ECU (and turbine) is powered by his own battery. If the receiver is shutted down by a loss of power, the ECU is still running with his own accu but detect the loss of the receiver => go to fail-safe mode.
Don't know this particular ECU, but with Jetcat ECU, a loss of signal don't come to a instant shut-off of the engine. When ther's a loss of signal, the ECU down the turbine to idle. If signal has not come ''on'' in the future 2 or 3 seconds, then the ECU shut-off the turbine immediately. (This is a way to permit recovery of the plane if loss of signal what temporaly)
ORIGINAL: Nhalyn
But this is not enough to say if it was a loss of power (servos are frozen where they are with no more movement), or a loss of signal between transmiter and receiver with receiver going in ''hold'' fail-safe mode. We need to know how were the settings of the fail-safe, and how work the ECU when it goes to fail-safe.
Regards.
But this is not enough to say if it was a loss of power (servos are frozen where they are with no more movement), or a loss of signal between transmiter and receiver with receiver going in ''hold'' fail-safe mode. We need to know how were the settings of the fail-safe, and how work the ECU when it goes to fail-safe.
Regards.
Bob
01-25-2011 | 06:20 AM
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From: Paris, FRANCE
RE: Go Pro camera + spectrum 2.4= failsafe.
ORIGINAL: rhklenke
If the servos loose power, then they do not "freeze" they are completely undriven and the surfaces can go to whatever position they are driven by the airflow over them...
Bob
If the servos loose power, then they do not "freeze" they are completely undriven and the surfaces can go to whatever position they are driven by the airflow over them...
Bob
01-25-2011 | 06:32 AM
#38
RE: Go Pro camera + spectrum 2.4= failsafe.
ORIGINAL: gruntled
Now why go and say somthing like that and perpetuate a myth when there is zero facts to back it up?
<br type=''_moz'' />
ORIGINAL: olnico
That's just another Spektrum lockout event.
That's just another Spektrum lockout event.
<br type=''_moz'' />
Mike
01-25-2011 | 08:38 AM
#39
My Feedback: (4)
RE: Go Pro camera + spectrum 2.4= failsafe.
The problem with perpetuating a myth is that you never come to solutions.
I crashed my L39 in BITW. I could have so easily blame the spektrum system (slow turn to the left, until it hit the ground, no failsafe). However, this is not the way I do things...
My dad and I picked everything up, and spent hours and hours checking and hypothesizing on possible situations (like a dr house diagnose). Luckily, I could check the batteries (they didn't break or explode). I had redundant batteries, and one of them was OK, but the other one was completely drained. My regulators where destroyed
So 2 possible scenarios could have happened:
1) one battery died, and the other one wasn't powerful enough to drive the system
2) I forgot to turn one on.
Further analyzing the crash, the plane crashed just before landing, on a full flap configuration. That points more towards scenario 2. The single battery (it was the 6th flight, one probably I should not have done) was not enough to carry through the whole flight, specially with the added load of the flaps down.
Then, the next thing my dad did was to understand discharge curves of lipos and see how the system reacts to low voltage and high loads. What we discovered (and is documented somewhere in a video on RCU) is that when power gets low the servos stop working (go soft) well before the receiver loses power. That perfectly describes the crash (slow turn, without the turbine shutting down). This is also another important learning. Low voltages will make servos stop working, no matter the brand of the receiver, well before the receiver stops working, it is not brown out what you need to fear, is losing power to the servos.
Net... I learned a lesson (expensive one), improved my power system, added a check point to my procedure, learned that redundancy is only worth it if one system can handle the plane, and hopefuly, won't crash again in the same fashion.
If after the crash I went crying "spektrum, spektrum...." (and believe me, for the first hour, that's all I wanted to do...) I would not have changed anything in my behaviour and I would be losing another plane.
I know I will hear 2000 experts after this post saying Im wrong. I don't care... I just want that 2 or 3 good friends (or unknown people) learn something and improve after reading this.
I can give more details of my set up to anyone if you shoot me a pm, don't want to name brands...
Later
Jack G
I crashed my L39 in BITW. I could have so easily blame the spektrum system (slow turn to the left, until it hit the ground, no failsafe). However, this is not the way I do things...
My dad and I picked everything up, and spent hours and hours checking and hypothesizing on possible situations (like a dr house diagnose). Luckily, I could check the batteries (they didn't break or explode). I had redundant batteries, and one of them was OK, but the other one was completely drained. My regulators where destroyed
So 2 possible scenarios could have happened:
1) one battery died, and the other one wasn't powerful enough to drive the system
2) I forgot to turn one on.
Further analyzing the crash, the plane crashed just before landing, on a full flap configuration. That points more towards scenario 2. The single battery (it was the 6th flight, one probably I should not have done) was not enough to carry through the whole flight, specially with the added load of the flaps down.
Then, the next thing my dad did was to understand discharge curves of lipos and see how the system reacts to low voltage and high loads. What we discovered (and is documented somewhere in a video on RCU) is that when power gets low the servos stop working (go soft) well before the receiver loses power. That perfectly describes the crash (slow turn, without the turbine shutting down). This is also another important learning. Low voltages will make servos stop working, no matter the brand of the receiver, well before the receiver stops working, it is not brown out what you need to fear, is losing power to the servos.
Net... I learned a lesson (expensive one), improved my power system, added a check point to my procedure, learned that redundancy is only worth it if one system can handle the plane, and hopefuly, won't crash again in the same fashion.
If after the crash I went crying "spektrum, spektrum...." (and believe me, for the first hour, that's all I wanted to do...) I would not have changed anything in my behaviour and I would be losing another plane.
I know I will hear 2000 experts after this post saying Im wrong. I don't care... I just want that 2 or 3 good friends (or unknown people) learn something and improve after reading this.
I can give more details of my set up to anyone if you shoot me a pm, don't want to name brands...
Later
Jack G
01-25-2011 | 08:59 AM
#40
RE: Go Pro camera + spectrum 2.4= failsafe.
Hi Jack,
Not blaming spectrum in anyway, i myself use JR/Spectrum. Just wanted to find out if the Go Pro could affect the signal in anyway as this roo has had 100s of flight with this setup but was the first flight with the GoPro mounted on. Unfortunately all was lost in the fire or else the batteries would be on the cycler first thing.
Chatty.
Not blaming spectrum in anyway, i myself use JR/Spectrum. Just wanted to find out if the Go Pro could affect the signal in anyway as this roo has had 100s of flight with this setup but was the first flight with the GoPro mounted on. Unfortunately all was lost in the fire or else the batteries would be on the cycler first thing.
Chatty.
ORIGINAL: JackD
The problem with perpetuating a myth is that you never come to solutions.
I crashed my L39 in BITW. I could have so easily blame the spektrum system (slow turn to the left, until it hit the ground, no failsafe). However, this is not the way I do things...
My dad and I picked everything up, and spent hours and hours checking and hypothesizing on possible situations (like a dr house diagnose). Luckily, I could check the batteries (they didn't break or explode). I had redundant batteries, and one of them was OK, but the other one was completely drained. My regulators where destroyed
So 2 possible scenarios could have happened:
1) one battery died, and the other one wasn't powerful enough to drive the system
2) I forgot to turn one on.
Further analyzing the crash, the plane crashed just before landing, on a full flap configuration. That points more towards scenario 2. The single battery (it was the 6th flight, one probably I should not have done) was not enough to carry through the whole flight, specially with the added load of the flaps down.
Then, the next thing my dad did was to understand discharge curves of lipos and see how the system reacts to low voltage and high loads. What we discovered (and is documented somewhere in a video on RCU) is that when power gets low the servos stop working (go soft) well before the receiver loses power. That perfectly describes the crash (slow turn, without the turbine shutting down). This is also another important learning. Low voltages will make servos stop working, no matter the brand of the receiver, well before the receiver stops working, it is not brown out what you need to fear, is losing power to the servos.
Net... I learned a lesson (expensive one), improved my power system, added a check point to my procedure, learned that redundancy is only worth it if one system can handle the plane, and hopefuly, won't crash again in the same fashion.
If after the crash I went crying "spektrum, spektrum...." (and believe me, for the first hour, that's all I wanted to do...) I would not have changed anything in my behaviour and I would be losing another plane.
I know I will hear 2000 experts after this post saying Im wrong. I don't care... I just want that 2 or 3 good friends (or unknown people) learn something and improve after reading this.
I can give more details of my set up to anyone if you shoot me a pm, don't want to name brands...
Later
Jack G
The problem with perpetuating a myth is that you never come to solutions.
I crashed my L39 in BITW. I could have so easily blame the spektrum system (slow turn to the left, until it hit the ground, no failsafe). However, this is not the way I do things...
My dad and I picked everything up, and spent hours and hours checking and hypothesizing on possible situations (like a dr house diagnose). Luckily, I could check the batteries (they didn't break or explode). I had redundant batteries, and one of them was OK, but the other one was completely drained. My regulators where destroyed
So 2 possible scenarios could have happened:
1) one battery died, and the other one wasn't powerful enough to drive the system
2) I forgot to turn one on.
Further analyzing the crash, the plane crashed just before landing, on a full flap configuration. That points more towards scenario 2. The single battery (it was the 6th flight, one probably I should not have done) was not enough to carry through the whole flight, specially with the added load of the flaps down.
Then, the next thing my dad did was to understand discharge curves of lipos and see how the system reacts to low voltage and high loads. What we discovered (and is documented somewhere in a video on RCU) is that when power gets low the servos stop working (go soft) well before the receiver loses power. That perfectly describes the crash (slow turn, without the turbine shutting down). This is also another important learning. Low voltages will make servos stop working, no matter the brand of the receiver, well before the receiver stops working, it is not brown out what you need to fear, is losing power to the servos.
Net... I learned a lesson (expensive one), improved my power system, added a check point to my procedure, learned that redundancy is only worth it if one system can handle the plane, and hopefuly, won't crash again in the same fashion.
If after the crash I went crying "spektrum, spektrum...." (and believe me, for the first hour, that's all I wanted to do...) I would not have changed anything in my behaviour and I would be losing another plane.
I know I will hear 2000 experts after this post saying Im wrong. I don't care... I just want that 2 or 3 good friends (or unknown people) learn something and improve after reading this.
I can give more details of my set up to anyone if you shoot me a pm, don't want to name brands...
Later
Jack G
01-25-2011 | 08:59 AM
#41
My Feedback: (24)
RE: Go Pro camera + spectrum 2.4= failsafe.
ORIGINAL: Nhalyn
It depends on the type of servos. Some comes very loose (on ground, control surface fall down by its own weight), some other just stay where they are.
It depends on the type of servos. Some comes very loose (on ground, control surface fall down by its own weight), some other just stay where they are.
Bob
01-25-2011 | 09:04 AM
#42
My Feedback: (4)
RE: Go Pro camera + spectrum 2.4= failsafe.
ORIGINAL: c_makhija
Hi Jack,
Not blaming spectrum in anyway, i myself use JR/Spectrum. Just wanted to find out if the Go Pro could affect the signal in anyway as this roo has had 100s of flight with this setup but was the first flight with the GoPro mounted on. Unfortunately all was lost in the fire or else the batteries would be on the cycler first thing.
Chatty.
Hi Jack,
Not blaming spectrum in anyway, i myself use JR/Spectrum. Just wanted to find out if the Go Pro could affect the signal in anyway as this roo has had 100s of flight with this setup but was the first flight with the GoPro mounted on. Unfortunately all was lost in the fire or else the batteries would be on the cycler first thing.
Chatty.
ORIGINAL: JackD
The problem with perpetuating a myth is that you never come to solutions.
I crashed my L39 in BITW. I could have so easily blame the spektrum system (slow turn to the left, until it hit the ground, no failsafe). However, this is not the way I do things...
My dad and I picked everything up, and spent hours and hours checking and hypothesizing on possible situations (like a dr house diagnose). Luckily, I could check the batteries (they didn't break or explode). I had redundant batteries, and one of them was OK, but the other one was completely drained. My regulators where destroyed
So 2 possible scenarios could have happened:
1) one battery died, and the other one wasn't powerful enough to drive the system
2) I forgot to turn one on.
Further analyzing the crash, the plane crashed just before landing, on a full flap configuration. That points more towards scenario 2. The single battery (it was the 6th flight, one probably I should not have done) was not enough to carry through the whole flight, specially with the added load of the flaps down.
Then, the next thing my dad did was to understand discharge curves of lipos and see how the system reacts to low voltage and high loads. What we discovered (and is documented somewhere in a video on RCU) is that when power gets low the servos stop working (go soft) well before the receiver loses power. That perfectly describes the crash (slow turn, without the turbine shutting down). This is also another important learning. Low voltages will make servos stop working, no matter the brand of the receiver, well before the receiver stops working, it is not brown out what you need to fear, is losing power to the servos.
Net... I learned a lesson (expensive one), improved my power system, added a check point to my procedure, learned that redundancy is only worth it if one system can handle the plane, and hopefuly, won't crash again in the same fashion.
If after the crash I went crying ''spektrum, spektrum....'' (and believe me, for the first hour, that's all I wanted to do...) I would not have changed anything in my behaviour and I would be losing another plane.
I know I will hear 2000 experts after this post saying Im wrong. I don't care... I just want that 2 or 3 good friends (or unknown people) learn something and improve after reading this.
I can give more details of my set up to anyone if you shoot me a pm, don't want to name brands...
Later
Jack G
The problem with perpetuating a myth is that you never come to solutions.
I crashed my L39 in BITW. I could have so easily blame the spektrum system (slow turn to the left, until it hit the ground, no failsafe). However, this is not the way I do things...
My dad and I picked everything up, and spent hours and hours checking and hypothesizing on possible situations (like a dr house diagnose). Luckily, I could check the batteries (they didn't break or explode). I had redundant batteries, and one of them was OK, but the other one was completely drained. My regulators where destroyed
So 2 possible scenarios could have happened:
1) one battery died, and the other one wasn't powerful enough to drive the system
2) I forgot to turn one on.
Further analyzing the crash, the plane crashed just before landing, on a full flap configuration. That points more towards scenario 2. The single battery (it was the 6th flight, one probably I should not have done) was not enough to carry through the whole flight, specially with the added load of the flaps down.
Then, the next thing my dad did was to understand discharge curves of lipos and see how the system reacts to low voltage and high loads. What we discovered (and is documented somewhere in a video on RCU) is that when power gets low the servos stop working (go soft) well before the receiver loses power. That perfectly describes the crash (slow turn, without the turbine shutting down). This is also another important learning. Low voltages will make servos stop working, no matter the brand of the receiver, well before the receiver stops working, it is not brown out what you need to fear, is losing power to the servos.
Net... I learned a lesson (expensive one), improved my power system, added a check point to my procedure, learned that redundancy is only worth it if one system can handle the plane, and hopefuly, won't crash again in the same fashion.
If after the crash I went crying ''spektrum, spektrum....'' (and believe me, for the first hour, that's all I wanted to do...) I would not have changed anything in my behaviour and I would be losing another plane.
I know I will hear 2000 experts after this post saying Im wrong. I don't care... I just want that 2 or 3 good friends (or unknown people) learn something and improve after reading this.
I can give more details of my set up to anyone if you shoot me a pm, don't want to name brands...
Later
Jack G
I doubt it had anything to do with the gopro. I do have to admit, 1200mah sounds very small. I don't know the discharge rate of A123, but if it where lions, you would not get enough power out of one. 2 1200 is ok, but if one failed (or the switch, or forgot to turn one on like i did) will leave you with very little juice to power your plane...
Again, don't know anything about A123
Later
Jack
01-25-2011 | 09:06 AM
#43
My Feedback: (24)
RE: Go Pro camera + spectrum 2.4= failsafe.
ORIGINAL: JackD
The problem with perpetuating a myth is that you never come to solutions.
I crashed my L39 in BITW. I could have so easily blame the spektrum system (slow turn to the left, until it hit the ground, no failsafe). However, this is not the way I do things...
My dad and I picked everything up, and spent hours and hours checking and hypothesizing on possible situations (like a dr house diagnose). Luckily, I could check the batteries (they didn't break or explode). I had redundant batteries, and one of them was OK, but the other one was completely drained. My regulators where destroyed
So 2 possible scenarios could have happened:
1) one battery died, and the other one wasn't powerful enough to drive the system
2) I forgot to turn one on.
Further analyzing the crash, the plane crashed just before landing, on a full flap configuration. That points more towards scenario 2. The single battery (it was the 6th flight, one probably I should not have done) was not enough to carry through the whole flight, specially with the added load of the flaps down.
[snip]
Later
Jack G
The problem with perpetuating a myth is that you never come to solutions.
I crashed my L39 in BITW. I could have so easily blame the spektrum system (slow turn to the left, until it hit the ground, no failsafe). However, this is not the way I do things...
My dad and I picked everything up, and spent hours and hours checking and hypothesizing on possible situations (like a dr house diagnose). Luckily, I could check the batteries (they didn't break or explode). I had redundant batteries, and one of them was OK, but the other one was completely drained. My regulators where destroyed
So 2 possible scenarios could have happened:
1) one battery died, and the other one wasn't powerful enough to drive the system
2) I forgot to turn one on.
Further analyzing the crash, the plane crashed just before landing, on a full flap configuration. That points more towards scenario 2. The single battery (it was the 6th flight, one probably I should not have done) was not enough to carry through the whole flight, specially with the added load of the flaps down.
[snip]
Later
Jack G
Bob
01-25-2011 | 09:26 AM
#44
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Joined: Oct 2010
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From: Paris, FRANCE
RE: Go Pro camera + spectrum 2.4= failsafe.
ORIGINAL: rhklenke
Actually, no it doesn't. All servos become undriven when they loose power - how else could it be? That fact that some fall by the weight of the surface on the ground depends on the surface weight, and also the type of motor and gear ratio in the servo - i.e., the amount of friction in the system. The only servo that will actually hold a position without power are those driven by a jackscrew, and I don't know of any of that type that are used in RC aircraft (and even in those, it really just a matter of a lot of friction in the gear train that is holding the position).
Bob
Actually, no it doesn't. All servos become undriven when they loose power - how else could it be? That fact that some fall by the weight of the surface on the ground depends on the surface weight, and also the type of motor and gear ratio in the servo - i.e., the amount of friction in the system. The only servo that will actually hold a position without power are those driven by a jackscrew, and I don't know of any of that type that are used in RC aircraft (and even in those, it really just a matter of a lot of friction in the gear train that is holding the position).
Bob
To JackD : +1 ! I like the way you do it and try to do the same, even if its not easy some times !
This last theory seems interresting : servos comming down as power decrease. This have to be dealed with the factthat that it was a gentle turn, not a violent one, so I'm surprise that all servos went down at the same time like it was a violent action that putting the voltage low....
It's not Doc House here ! It's more NCIS !!!
01-25-2011 | 09:33 AM
#45
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From: Caracas, VENEZUELA
RE: Go Pro camera + spectrum 2.4= failsafe.
One of the lessons learned after Gerardo's L-39 crash, was the dramatic difference between Li-Po and Li-Ion regarding battery voltage versus remaining capacity.
The easiest way to illustrate this point is with the attached chart.
Basically, at the voltage where a Li-Ion still has about 50% of its capacity remaining, a Li-Po is almost totally drained.
This is mandatory to understand, specially if you use both types of batteries. Checking battery voltage will be useless unless this is fully understood.
Jack
(I am trying to upload the chart with no luck. Let me keep trying)
The easiest way to illustrate this point is with the attached chart.
Basically, at the voltage where a Li-Ion still has about 50% of its capacity remaining, a Li-Po is almost totally drained.
This is mandatory to understand, specially if you use both types of batteries. Checking battery voltage will be useless unless this is fully understood.
Jack
(I am trying to upload the chart with no luck. Let me keep trying)
01-25-2011 | 10:02 AM
#46
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From: Caracas, VENEZUELA
RE: Go Pro camera + spectrum 2.4= failsafe.
No luck uploading. Let me type it.
DISCHARGE CURVES @ 1.0 AMP LOAD
VOLTS / LI-PO DRAINED CAPACITY / LI-ION DRAINED CAPACITY
7.8 / 15% / 0%
7.7 / 23% / 2%
7.6 / 30% / 5%
7.5 / 40% / 8%
7.4 / 55% / 13%
7.3 / 76% / 22%
7.2 / 90% / 35%
7.1 / 94% / 44%
7.0 / 97% / 51%
6.9 / 100% / 66%
6.8 / 100% / 84%
6.7 / 100% / 95%
6.6 / 100% / 100%
Jack
It is a mess.
First column is battery voltage
Second column is Li-Po drained capacity
Third column is Li-Ion drained capacity
DISCHARGE CURVES @ 1.0 AMP LOAD
VOLTS / LI-PO DRAINED CAPACITY / LI-ION DRAINED CAPACITY
7.8 / 15% / 0%
7.7 / 23% / 2%
7.6 / 30% / 5%
7.5 / 40% / 8%
7.4 / 55% / 13%
7.3 / 76% / 22%
7.2 / 90% / 35%
7.1 / 94% / 44%
7.0 / 97% / 51%
6.9 / 100% / 66%
6.8 / 100% / 84%
6.7 / 100% / 95%
6.6 / 100% / 100%
Jack
It is a mess.
First column is battery voltage
Second column is Li-Po drained capacity
Third column is Li-Ion drained capacity
01-25-2011 | 10:06 AM
#47
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From: San Jose,
CA
RE: Go Pro camera + spectrum 2.4= failsafe.
You may want to try using a UBEC with LiPo packs. I have been using them for a few years now and haven't had any issues. I use 11.1 volt 3S LiPo packs (1320 to 2100 mah packs) regulated to 5 or 6 volts depending on the servos. With the higher voltage you can use smaller packs and they last for 4-5 flights and are still at 50%.
You can also use 2S packs (7.4 volts), but they go faster because of the lower voltage, but still work great.
Jeff
You can also use 2S packs (7.4 volts), but they go faster because of the lower voltage, but still work great.
Jeff
01-25-2011 | 10:15 AM
#48
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From: Paris, FRANCE
RE: Go Pro camera + spectrum 2.4= failsafe.
I prefer use 2 cells lipo pack because it make less work to the regulator to down the voltage to 5.5 or 6 V when nominal is 7.4V (8.4V full charge).
Work well on nearly all my planes now (and all the bigger). My tow plane have 5 hours of possible flight (demonstrated) with only 2x 2cells 2200mAh Lipo. Engine Zenoah ZG62, airplane 102in span, 10.5kg without petrol.
In fact with 3 cells most of regulators will deliver less amperes to the servo than with 2 cells : read carefully the specs.
Work well on nearly all my planes now (and all the bigger). My tow plane have 5 hours of possible flight (demonstrated) with only 2x 2cells 2200mAh Lipo. Engine Zenoah ZG62, airplane 102in span, 10.5kg without petrol.
In fact with 3 cells most of regulators will deliver less amperes to the servo than with 2 cells : read carefully the specs.
01-25-2011 | 10:24 AM
#49
RE: Go Pro camera + spectrum 2.4= failsafe.
ORIGINAL: mikedenilin
I have a few questions regarding the A123 with JR1222 setup.
1. Will a shorted battery drain the other good battery in a JR1222 receivers if they are hooked up directly to the receiver?
2. Will the 6.6V power supply damage JR8411, 8711 circuits and cause a short circuit?
here is the link to the JR1222 RX info.
http://www.horizonhobby.com/Products...222#quickSpecs
Thanks,
Mike
I have a few questions regarding the A123 with JR1222 setup.
1. Will a shorted battery drain the other good battery in a JR1222 receivers if they are hooked up directly to the receiver?
2. Will the 6.6V power supply damage JR8411, 8711 circuits and cause a short circuit?
here is the link to the JR1222 RX info.
http://www.horizonhobby.com/Products...222#quickSpecs
Thanks,
Mike
An internal short in one cell was the "normal" failure mode wit NiCd cells. This was enough to drop your battery voltage by at least 25%, and this in turn is often enough to crash your model.
In an A123 the result would be even more devastating as you would loose at least 50% of your voltage. Then again, I have not had an A123 cell fail as yet, so I have no idea what the failure mode is. (any info guys?)
Even if you get this fairley gentle mode of failure in a twin battery system, without diodes to separate the two batteries, the one that goes bad will always drain the good one. The salient question is "in how long?". The answer maybe two minutes or two days, but if you do not have separation you are playing dice.
As an added advantage to those worried about servos being sensitive to overvoltage is that the diodes reduce the voltage slightly.
I use 8411's 8511's and a bunch of other servos on A123's. What I never do is charge and fly. I charge the day before, then if I recharge on the field, I fly something else for an hour and let the peak voltage settle. It has worked so far.
01-25-2011 | 12:09 PM
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From: Southport, UNITED KINGDOM
RE: Go Pro camera + spectrum 2.4= failsafe.
Great videos Staale, thanks for the pics of the install, for me I prefer the external videos with less restricted view, ice runway is interesting. I have done some inflight movies recently but only with the cheap chinese key chain type, the GoPro seems to be the way to go for good quality HD movies. Ideally I would like to find a smaller camera but still with reasonable resolution.....any ideas?
Rob.
Rob.
