Control redundancy with gyro single point of failure crash
05-29-2021, 11:14 AM
#1
Thread Starter
Control redundancy with gyro single point of failure crash
Is there a way to retain control (backup control) on a plane that has all controls run through a gyro?
I list my problem below to bring you along to where I arrived. I’d rather have the question above answered about redundancy.
it seems to me that using a gyro increases likelihood of control failure. I’ve crashed my foamie (ten?) times this past year and I’m tiring of it. I have been swapping components to eliminate the problem, but it comes back as inconclusive, and crashes continue. My stubbornness is fading.
I am aware of 2.4ghz satellite receivers, and that handles radio signal redundancy... not the same thing.
This example uses 72mhz.
Here is what I’ve experienced: Been flying all my life 30 plus yrs. I am not about to put my first gyro in one of my nice planes for anything. However, let’s build a foam board foamie and play! Good thing that I didn’t put it in something nice.
plane flies fine. Gyro works in all modes, and I am slowly dialing it in. I’m excited. This gyro thing is cool. 6min flight time on a battery. At any given minute, the plane LOCKS OUT CONTROLS and crashes. It’s not every flight, but could be every 2-3. Now, I have routinely been within 4 sec from the ground by vertical dive so I have yet to recover. The last lockout occurred and as ground contact in a dart like profile is assured, I rammed throttle full to see if I still have throttle. IT DOES! so I still have radio control. Throttle is not part of the gyro. Most crashes occur with gyro OFF... and this means that primary controls pass through the unit without influence.
30oz foamie
supertigre .10 brushless outrunner motor current draw within spec using lipo.
large hobbywing esc ...60A probably and mid-timing standard used.
separate rx batt pack 5 cell (for gyro volt requirements) nimh and red esc wire removed from connection
(I’ve tried bec as well to no change regarding crashes)
HITEC HG3XA gyro
airtronics rd8000 72mhz
airtronics old style receiver,(92765) polarity corrected
futaba servos from 1995.
hitec cust service says that they have not heard of this. While they offer to take the gyro back, it has performed as it is supposed to, so I’m not sending it back. Sending it back is hard when I don’t know the problem. I want this to work so bad.
72mhz is fine they say
servos are fine they say. (Analog)
Ready for my theory?
initial power up of the gyro locks controls as the unit calibrates. All gyros do this right? So IF during flight, the power circuit experiences an open for a fraction of a second, then the controls lockout as the gyro initializes, and plane crashes since I’m always low enough (Of course it hasn’t locked up at safe altitude). This explains why I still had throttle control during the last lockout about 1 sec before impact.
Why aren’t other people having this happen? I have ensured that power wires are in good shape and wiggle checked them on resistance scale of a meter. They are new too. I’ve used other servos. The next thing to swap is the receiver, but now I’m on a witch hunt because HITEC says that the setup is fine.
What is YOUR opinion?
ANY IDEAS?
and of course, the main reason for this post is to find out how to instill control redundancy when using a gyro. A $500 demon cortex is useless to me if it’s a single point of failure.
until this is solved and until I have a backup control system, I have no intent of putting a gyro in anything big that carries responsibility (like a 40 size plane). Granted, most manufacturers state that gyros are for smaller planes.
andy
I list my problem below to bring you along to where I arrived. I’d rather have the question above answered about redundancy.
it seems to me that using a gyro increases likelihood of control failure. I’ve crashed my foamie (ten?) times this past year and I’m tiring of it. I have been swapping components to eliminate the problem, but it comes back as inconclusive, and crashes continue. My stubbornness is fading.
I am aware of 2.4ghz satellite receivers, and that handles radio signal redundancy... not the same thing.
This example uses 72mhz.
Here is what I’ve experienced: Been flying all my life 30 plus yrs. I am not about to put my first gyro in one of my nice planes for anything. However, let’s build a foam board foamie and play! Good thing that I didn’t put it in something nice.
plane flies fine. Gyro works in all modes, and I am slowly dialing it in. I’m excited. This gyro thing is cool. 6min flight time on a battery. At any given minute, the plane LOCKS OUT CONTROLS and crashes. It’s not every flight, but could be every 2-3. Now, I have routinely been within 4 sec from the ground by vertical dive so I have yet to recover. The last lockout occurred and as ground contact in a dart like profile is assured, I rammed throttle full to see if I still have throttle. IT DOES! so I still have radio control. Throttle is not part of the gyro. Most crashes occur with gyro OFF... and this means that primary controls pass through the unit without influence.
30oz foamie
supertigre .10 brushless outrunner motor current draw within spec using lipo.
large hobbywing esc ...60A probably and mid-timing standard used.
separate rx batt pack 5 cell (for gyro volt requirements) nimh and red esc wire removed from connection
(I’ve tried bec as well to no change regarding crashes)
HITEC HG3XA gyro
airtronics rd8000 72mhz
airtronics old style receiver,(92765) polarity corrected
futaba servos from 1995.
hitec cust service says that they have not heard of this. While they offer to take the gyro back, it has performed as it is supposed to, so I’m not sending it back. Sending it back is hard when I don’t know the problem. I want this to work so bad.
72mhz is fine they say
servos are fine they say. (Analog)
Ready for my theory?
initial power up of the gyro locks controls as the unit calibrates. All gyros do this right? So IF during flight, the power circuit experiences an open for a fraction of a second, then the controls lockout as the gyro initializes, and plane crashes since I’m always low enough (Of course it hasn’t locked up at safe altitude). This explains why I still had throttle control during the last lockout about 1 sec before impact.
Why aren’t other people having this happen? I have ensured that power wires are in good shape and wiggle checked them on resistance scale of a meter. They are new too. I’ve used other servos. The next thing to swap is the receiver, but now I’m on a witch hunt because HITEC says that the setup is fine.
What is YOUR opinion?
ANY IDEAS?
and of course, the main reason for this post is to find out how to instill control redundancy when using a gyro. A $500 demon cortex is useless to me if it’s a single point of failure.
until this is solved and until I have a backup control system, I have no intent of putting a gyro in anything big that carries responsibility (like a 40 size plane). Granted, most manufacturers state that gyros are for smaller planes.
andy
