General HBZ Carbon Cub Problem

[Loopy]

Hi Guys/Gals,

I recently removed and replaced all the electronics from a severally damaged HBZ Carbon Cub 1.3 fuselage into a new one. I added the flap servo to the wing as well. All functions were working according to plan. The plane took off as normal, but shortly after takeoff the motor quit. Landed w/o damage. I noted that the light in the Safe Control had changed from green to red. I checked all connections and the battery was over 50% charged. On the ground the motor ran as normal, but the aileron servos jittered when activated. Flew it again with the same results. (DUH)There is no mention of this phenomenon in the trouble shooting guide.
Any suggestions or advice gratefully accepted.

 

[RandyDSok]

Since I don't know your experience level etc....

You said the battery was over 50% charged... On a Lipo battery that would be right about 3.6-3.7v per cell ( also called a storage charge ) and that wouldn't be very much and could, if under load... mean you would have had much lower battery voltage and had hit LVC ( low voltage cutoff ). Normally, if you hit LVC on that aircraft, it should pulse the throttle indicating it's low on power, so I suspect something else it going on since you didn't mention that.

So the first thing would be to check with a different battery that is fully charged. If that is what you did ( remember you didn't say that, you just said you flew again but didn't specify the details ), then you'd want to start checking all of your connections to make certain they aren't loose.

 

[Loopy]

Since I don't know your experience level etc....

You said the battery was over 50% charged... On a Lipo battery that would be right about 3.6-3.7v per cell ( also called a storage charge ) and that wouldn't be very much and could, if under load... mean you would have had much lower battery voltage and had hit LVC ( low voltage cutoff ). Normally, if you hit LVC on that aircraft, it should pulse the throttle indicating it's low on power, so I suspect something else it going on since you didn't mention that.

So the first thing would be to check with a different battery that is fully charged. If that is what you did ( remember you didn't say that, you just said you flew again but didn't specify the details ), then you'd want to start checking all of your connections to make certain they aren't loose.

Since I don't know your experience level etc....

You said the battery was over 50% charged... On a Lipo battery that would be right about 3.6-3.7v per cell ( also called a storage charge ) and that wouldn't be very much and could, if under load... mean you would have had much lower battery voltage and had hit LVC ( low voltage cutoff ). Normally, if you hit LVC on that aircraft, it should pulse the throttle indicating it's low on power, so I suspect something else it going on since you didn't mention that.

So the first thing would be to check with a different battery that is fully charged. If that is what you did ( remember you didn't say that, you just said you flew again but didn't specify the details ), then you'd want to start checking all of your connections to make certain they aren't loose.

Thanks Randy, I am more than a beginner but a long way from an expert. The battery had no more the 2-3 minutes on it from full charge and checked OK. I didn't try a a different battery, but will do so. I have checked connections.

 

[RandyDSok]

I never go by flight time to judge a batteries capacity... In fact, I've gone through a 2200mah 3S battery in under 5 minutes by flying at full throttle. I'd also suggest you get one of those little battery testers that you can plug in and it reads back each cell's voltage. A single bad cell can also cause a battery to not last long as well. I think the little checkers are around $10-15 with the fancier ones in the $20 range, so not bad for a bit of piece of mind and a quick check. Still, to repeat myself, I'm not thinking battery since the motor throttle should have pulsed ( according to the manual ). The battery and connections are always the most likely in these cases.

 

[Loopy]

I never go by flight time to judge a batteries capacity... In fact, I've gone through a 2200mah 3S battery in under 5 minutes by flying at full throttle. I'd also suggest you get one of those little battery testers that you can plug in and it reads back each cell's voltage. A single bad cell can also cause a battery to not last long as well. I think the little checkers are around $10-15 with the fancier ones in the $20 range, so not bad for a bit of piece of mind and a quick check. Still, to repeat myself, I'm not thinking battery since the motor throttle should have pulsed ( according to the manual ). The battery and connections are always the most likely in these cases.

I have a battery tester. I just tried 2 other batteries with the same results. I fear that the "safe" mode system is toast. Normally after you plug the battery in and right the plane, the control surfaces wiggle and the "safe" mode lights to green, the elevator will pulse up or down as the plane is tilted up or down. Does not happen now. The control surfaces wiggle the lights a red and there is no elevator function to match the up/down tilt of the plane.

 

[RandyDSok]

I'm afraid I'm of no help with any gyro assisted equipment... I never needed it even during the time I was learning. So sorry about that.

 

[Loopy]

My next option is to just unhook the "safe" mode and try it.

Thanks for your support!!!!

 

[Fly-n-Low]

Rebind the TX and RX. When all else fails, that is what I do. I usually rebind after I rig and mount everything, IF I cat get to the RX.

Looks they have changed up the electronics on the new CC compared to mine SC and CC. The HZ Sport Cub (same bird different electronics) has no light but has SAFE. And the CC with the GPS, SAFE, etc., everything is enclosed with no light.

I need to get my CC with the GPS out and mess with it. It is supposed to fly itself to a certain extent. I'd like to see how good it is...

PS have you noticed that you need to add a decent amount of rudder to keep it coordinated in a turn? Maybe more than necessary? I see it on the HZ SC. More so than on other models I have. So I added a bit of rudder mix to the ailerons. Also added elevator mix to the flaps. That thing will hang on approach with full flaps! Just control sink rate with the throttle. I love mine!

 

[Fly-n-Low]

And depending in the impact, it may have fried the gyros.... Hope not.

 

[Loopy]

Rebind the TX and RX. When all else fails, that is what I do. I usually rebind after I rig and mount everything, IF I cat get to the RX.

Looks they have changed up the electronics on the new CC compared to mine SC and CC. The HZ Sport Cub (same bird different electronics) has no light but has SAFE. And the CC with the GPS, SAFE, etc., everything is enclosed with no light.

I need to get my CC with the GPS out and mess with it. It is supposed to fly itself to a certain extent. I'd like to see how good it is...

PS have you noticed that you need to add a decent amount of rudder to keep it coordinated in a turn? Maybe more than necessary? I see it on the HZ SC. More so than on other models I have. So I added a bit of rudder mix to the ailerons. Also added elevator mix to the flaps. That thing will hang on approach with full flaps! Just control sink rate with the throttle. I love mine!

Thanks, I was considering that. Just didn't think I would need to.

 

[Loopy]

And depending in the impact, it may have fried the gyros.... Hope not.

Me too!!! It's been clobbered quite hard, but everything functioned as it was supposed to at first.

I'm not sure just what would be needed to replace. The 2 units that light up are not replaceable parts.

 

[Fly-n-Low]

Worse comes to worse, they make RX with SAFE if you have to have it. Other wise an AR620 would work.

Randy is right though on the motor. When the batter starts running out, it will oscillate. Kind of like on a rev-limiter. Mine would do it under full throttle, and you could let off and be fine for a landing. It won't cut completely off unless the bat is on it's death bed. Reason being, if you run it that far down, it will never fully recover a full charge.

 

[Loopy]

Worse comes to worse, they make RX with SAFE if you have to have it. Other wise an AR620 would work.

Randy is right though on the motor. When the batter starts running out, it will oscillate. Kind of like on a rev-limiter. Mine would do it under full throttle, and you could let off and be fine for a landing. It won't cut completely off unless the bat is on it's death bed. Reason being, if you run it that far down, it will never fully recover a full charge.

I know. The motor did not oscillate. When that happens there will also be a beeping notification in the TRX. The motor just died. Other batts did not work either. That's just not the problem. I may just unhook its safe mode and fly like an expert, hopefully. What is the # of the "safe" rcvr just in case?

 

[RandyDSok]

Thanks, I was considering that. Just didn't think I would need to.

OH SHAW... An ounce of prevention is worth a pound of cure ( First saying was what my grand parents would use to express me being a bit silly in not trying something especially if it was easy to check, the second was from Benjamin Franklin about it being easier to prevent a fire than to fight a fire ).

You need to always be a little bit of a type-a person with these things and it will likely save you time and money later on in the end. Even on things you may not think matters, if it doesn't that that long to double check, just do it to make certain that it isn't an issue and at most you've only lost a few moments of time but may save having another crash because you didn't go over everything with a fine tooth comb ( as they say ).

Like that jitter you mentioned on the ailerons, did you check further into that? If they worked fine before the crash and now jitter a bit afterword, then something changed even if it's only by a smidge. I'd pop the clevis' loose at the servo ( or servos if more than one ) and check if there is any binding on the pushrods going to both of the ailerons. If there is some resistance ( more than what you think is normal ), find out what is out of whack and binding things up. If they seem to work smoothly, perhaps there is an issue with the servo ( s ) themselves that could explain that as well as also explain a possible drain on power as well ( since the servo may need more power ( amps ) to operate ).

Always approach these types of issues with that type of skepticism and you'll end up avoiding more wrecks in the future as well as develop your own sense of diagnostic thinking on future things you may come up against. Of course, it will take a little bit more time, but it could save you later just as easy.

 

[Loopy]

OH SHAW... An ounce of prevention is worth a pound of cure ( First saying was what my grand parents would use to express me being a bit silly in not trying something especially if it was easy to check, the second was from Benjamin Franklin about it being easier to prevent a fire than to fight a fire ).

You need to always be a little bit of a type-a person with these things and it will likely save you time and money later on in the end. Even on things you may not think matters, if it doesn't that that long to double check, just do it to make certain that it isn't an issue and at most you've only lost a few moments of time but may save having another crash because you didn't go over everything with a fine tooth comb ( as they say ).

Like that jitter you mentioned on the ailerons, did you check further into that? If they worked fine before the crash and now jitter a bit afterword, then something changed even if it's only by a smidge. I'd pop the clevis' loose at the servo ( or servos if more than one ) and check if there is any binding on the pushrods going to both of the ailerons. If there is some resistance ( more than what you think is normal ), find out what is out of whack and binding things up. If they seem to work smoothly, perhaps there is an issue with the servo ( s ) themselves that could explain that as well as also explain a possible drain on power as well ( since the servo may need more power ( amps ) to operate ).

Always approach these types of issues with that type of skepticism and you'll end up avoiding more wrecks in the future as well as develop your own sense of diagnostic thinking on future things you may come up against. Of course, it will take a little bit more time, but it could save you later just as easy.

I could just change my name to CRASH!!!

 

[RandyDSok]

I almost tried a Loopy Crash one time... it wasn't fun, needed to change my pants after words.... LOLOL

 

[Fly-n-Low]

All of my feathers twitch when SAFE initialized and the TX and RX have mated?

 

[Loopy]

All of my feathers twitch when SAFE initialized and the TX and RX have mated?

Yes. Reminds me of videos I've seen of honey bees twitching their tails when informing the hive of new flower teritory.

 

[Loopy]

Rebind the TX and RX. When all else fails, that is what I do. I usually rebind after I rig and mount everything, IF I cat get to the RX.

Looks they have changed up the electronics on the new CC compared to mine SC and CC. The HZ Sport Cub (same bird different electronics) has no light but has SAFE. And the CC with the GPS, SAFE, etc., everything is enclosed with no light.

I need to get my CC with the GPS out and mess with it. It is supposed to fly itself to a certain extent. I'd like to see how good it is...

PS have you noticed that you need to add a decent amount of rudder to keep it coordinated in a turn? Maybe more than necessary? I see it on the HZ SC. More so than on other models I have. So I added a bit of rudder mix to the ailerons. Also added elevator mix to the flaps. That thing will hang on approach with full flaps! Just control sink rate with the throttle. I love mine!

I did the re-bind and VIOLA!!!! The green light came on!!! I haven't had the chance to test it in flight yet, but my bet is that it works.

 

[Loopy]

I did the re-bind and VIOLA!!!! The green light came on!!! I haven't had the chance to test it in flight yet, but my bet is that it works.

I finally got around to the flight test and my problem is solved!!!!