300X Power Loss;

[C_M_H]

Okay, looking for some input on a problem I'm having/had. Sorry for the long post, but the details might help;

A few weeks ago my stock 300X had a loss of power & fell from the sky. By the time I got to it, the servos were active, and it seemed like it was fast enough that if the AR7200BX had reset, it would still be initializing ( and so the servos would not be responding ). The batteries all are fresh and the amount charged back in was minimal. ESC showed no signs of capacitor de-solder.....

Everything checked out okay & no apparent damage, so I thought I'd try one more test flight so if the problem would repeat & I could look for reset, etc..

Got it up in the air, working fine, then it just exploded. Looked like it crumpled in on itself. Gathered the parts & headed home. When am I gonna learn that with these heli's if you even think there's a problem, ground it & bench test it.....

So I decided to put a Talon 35 in it to eliminate the ESC possibility. Few great for awhile ( 20-30 flights ), then started with the power loss again. Mostly low to the ground, maybe even when I switched Idle-Up off..... So again, one more battery to "test" it out, working good, then no power, this time from high enough to do some damage. I'll save that for another post.

So I ask at the LHS about this. He says 2 other guys with 300X's have had this same exact problem, and solved it by adding a satellite to the AR7200BX. I happen to have a satellite from one of my planes, so I put it on, and flew 4 batteries this morning. No problems.

What the heck? Why would this help? Most of the power-losses were within 10ft of the hell.

My 450X with same transmitter and an AR7200BX w/stock esc is working fine....

I guess I should be happy if it works with the satellite, but I really don't like not knowing exactly what's going on.

Anybody else have this problem?

Thanks,

Craig

[Uriah]

This is just a thought. Perhaps you're experiencing voltage spikes from static buildup, which could cause the built-in receiver to go funky and make the AR7200BX attempt to reset itself. Maybe the installation of the sat to the front of your bird is simply masking the problem. Perhaps try some silicone on the belt?

DoubleCH or some of the other "setup gurus" would probably have some better insight into your problem. But since you've switched batteries and swapped ESCs, static buildup or a bad FBL unit are the only things I can think of at the moment that might cause this.

[helibus]

Brief power cutouts are more common than they should be. "Fixes" have been all over the map - perhaps because it could be there are multiple things that can cause it, or that what is described as a single fix is often incorporated as part of a repair or rebuild that could have affected other things.

• Resolving vibrations, some that you can't see
• Fixing surge capacitor on the ESC broken free from the board
• Replacing bad or suspect ESC/BEC
• Replacing servo(s) that evidently put undue spike loads on the BEC
• Changing BX antenna placements
• Rerouting of the ESC cable to the BX so it isn't close to the BX antenna wires
• Providing static discharge path(s) throughout the heli
• Addition of satellite receiver to the BX
• Adding a ferrite ring on the cable between ESC and BX as good measure
• Fixing frayed wires and poorly soldered connections
• Properly insulating motor bullet connectors
• Added sleeving to BX antennae so they are less prone to resonate & pass vibes into BX

In my case I kept seeing a cutout nearly every battery after a dumb-thumb incident. Logging data from the Castle Edge Lite 50 told me the BX was dropping the throttle signal for 100 to 150 mSec, causing the ESC to then go through slow-start (I'd hit the ground first!). Eventually rerouted some wires and worked through a vibe I could see on the skids and the short BX antenna; about 100 flights now with no issues.

EDIT: Performing a global google search using the likes of "300x cuts out", "300x brown out", "300x power loss" brings up several of the older threads where these have been discussed.

[C_M_H]

Thanks for the input guys.

I have siliconed my belt, but you never know.

In thinking about it I think the BX dropping the throttle signal is possibly the right track. Somehow the slow start idea is making sense.

Will continue to explore.....

[Uriah]

This is NOT a rebuttal. I'm just thinking out loud in response to helibus' post. Please don't take it personal, helibus.



"vibrations, some that you can't see"

Vibrations tend to cause the RROD (right roll of death) on the AR7200BX more than anything else. Vibe induced power failures and brownouts are indeed a possibility, I suppose, though I've never experienced vibe-induced brownouts and power failures on any of my birds.
-
"Surge capacitor on the ESC broken free from the ESC"
"Bad ESC"

He said he swapped out the ESC and battery, so I'm going assume that it's most likely not the ESC or BEC. Unless he's just an unlucky turd that has two bad ESCs.
-
"Bad servo(s) evidently putting undue spike loads on the BEC"

While bad/failing servos can cause brownouts, I don't see how it could be bad servos in this particular case because of the simple fact that adding a sat has apparently resolved (or at least masked) his issue. If it was the servos, I would assume the problem would exist regardless of the installation of a sat. Perhaps I'm missing something?
-
"Antenna placement"

His AR7200BX is in a standard location (upper tray). In his case I think this is unlikely.
-
"Routing of the ESC cable to the BX so it isn't close to the BX antenna wires"

This is a possibility. You can indeed create ground loops and the like on these birds, which can introduce RF/EMI noise into the electronics.
-
"Static"

This is a possibility and was my first thought. Voltage spikes can cause some crazy stuff. But he said he's put silicone on the belt, and that usually takes care of most static issues on most birds.
-
"Fixed by addition of satellite"

The 300X is known to fly quite reliably on the AR7200BX's built-in receiver. I've even flown 300Xs on other FBL units with single sats and no full-size receiver. If an extra satellite fixes the problem on a 250 size bird, I'm inclined to think it's simply masking a problem and not actually fixing it.
-
I'm anxious to see what DoubleCH has to say. He seems to always have a good answer.

[helibus]

Originally Posted by C_M_H

In thinking about it I think the BX dropping the throttle signal is possibly the right track. Somehow the slow start idea is making sense.

Here's a link to a post that has a logging data graph from my experience. That 150 mSec drop in the throttle signal took six seconds for the Castle ESC to recover from... Six seconds is a l-o-n-g time for an in-flight bird. This is from a low-level hover test where I was able to land after the cutout, wait for the slow start recovery, take off, and complete the flight. https://www.helifreak.com/showpost.p...&postcount=731

I've dropped back to a Talon 35 to save some weight at a sacrifice of the logging data, but will now always have the ESC set up for autorotation bailout enabled. That shaves maybe a second or two off the RPM recovery, should I run into this again.

Again, I can't say this is what is happening in your case.

EDIT: Let me be the first to remind all that there are sample rate limitations in the Castle logging that could have missed things like blips in the BEC output. I didn't have any telemetry data, so all I had to work with in troubleshooting was the Castle logging data and trying what other people had already discussed as fixes, incorporating each one at a time. What I can say is that in the six or so flights of varying data points and sample rates, ALL I ever saw as anomalous in the logging data was the drop out in the throttle signal from the BX. I never saw (er, at least caught) any blip in the battery voltage, BEC output, temperature sensor, current draw, etc.

[helibus]

Originally Posted by Uriah

I'm anxious to see what DoubleCH has to say. He seems to always have a good answer.

Agreed. I do believe he's one that reported his cutouts went away when he moved onto different servos (after also moving to a new BEC first and still seeing a cutout).

All I've done is try to summarize what experiences people have shared in the year I've been reading 300x threads. All but one are not my experiences, so I can't take any rebuttal personally.

EDIT: Man. I've sure observed that has helicopters get bigger, experts get stronger and stronger opinions on how any experience they haven't had can't be real and aren't worth any merit.

[Uriah]

Originally Posted by helibus

EDIT: Man. I've sure observed that has helicopters get bigger, experts get stronger and stronger opinions on how any experience they haven't had can't be real and aren't worth any merit.

If that edit was in response to my first point in my last post... I took care to specify that, while I hadn't experienced vibe-induced brown-outs, I'm not going to discount the possibility that it can happen. If that edit wasn't a direct response to anything I've said, just ignore this post.

[C_M_H]

I thought I'd post an update for general knowledge and thanks to everyone who offered help.

After quite awhile on the bench waiting for parts & such, I've got my 300 back in the air and working pretty darn well.

You guys we're right, it was a vibration issue. Apparently under certain vibes the AR7200BX just shuts off the throttle. Servos still work, no brown-out light on the AR, no RROD, just cut-off throttle.

I was able to "reliably" get it to shut down while hovering a couple feet off the ground every time. At this point my frame was so beat I didn't care if it hit the dirt.

After checking everything I could think of, I caved and bought the USB adapter and updated my AR to the latest firmware ( it had been running a 2.X version ).

And, rather than glue my busted-@ss frame together again, I upgraded my frame to a CFX frame, so there went any chance of isolating the fix. Maybe the main bearings were bad ( felt fine ), maybe I had firmware voodoo ( unlikely I think ). I dunno.

Bottom line is vibes do shut-off the throttle, and in such a way I'd have sworn it was a brown-out or the ESC's fault.

In any case I'm happy to say she's in the air again. I sure do like this little heli.

[stablehover]

This posted kinda of like a question to Uriah, Helibus and CMH. I had almost what I think is the same issue tonight. My 300X is almost stock except for Lynx plastic blades and Lynx frame stiffener. When I first tried to initialize my 300 tonight it would not on first try. Second try was fine. I flew for a moment in normal mode went to idle up and flew around all was fine and then all of a sudden BOOM! No motor, no servo responses, nothing. I was lucky I was flying on a big downslope and it just literally settled on the skids and the tail fin hooked and it was fine. Flew again, BAD PLAN and the same thing happened in a backward circuit and I plowed in on the tail and just mashed the thing it is an ugly scene. This heli is approaching two hundred flights with zero issues. I am literally an electronic moron. I can do mechanical set-ups just fine the electronic part slays me. Did I just have the same issue as CMH? I could swear that I have hardly any vibes but maybe I do. Any thoughts? Thank you guys in advance.

[C_M_H]

Man that sucks.

I think ( hope ) I've finally learned that if I even think something is not right I land and take it home for inspection. Putting another battery in to see if it does it again didn't really work out for me.

It was at flight #95 mine started acting up. As for the vibes, I swear I could not find anything. It looked solid, flew solid, except for the drop-like-a-brick-out-of-the-sky part.

It funny, because my 450X had some vibes for awhile where the tips of the landing skids and tail fin were a blur they shook so much. But it didn't affect the AR7200BX at all. It made me nervous, so I chased them down, but no throttle shut off, odd rolls, or anything.....

So all I can say is when you get it back together, stay low to the ground and fly a few batteries to see if it will happen. Of course in fixing you may replace whatever part was causing the problem in the first place.

In any event hang in there. It's awful when it doesn't work, but worth it when it does.....

[stablehover]

Yeah was so surprised I had zero power. I could not flare, pull up the tail, anything I tried everything in like a three second span and it just hit really hard. I broke everything from frame back, both main grips and I'm sure the main shaft and feathering shaft are cooked, main gear has a chip I think from hitting pinion. Heck I had the best throttle hold in the world I had no power. I wish somebody could say this is what it was. The heli has never been crashed. I was like what the hell? The funny thing about it was in the middle of this big pile of parts and pieces the heli had initialized and all the cyclics worked. LOL.

[Scream]

I had something similar happen and the sheer frustration of watching her fall and not having a solid answer why was really discouraging, luckily you're definitely in the right spot!

IF your rocking the Bx, consider getting the spectrum flight log. Its $20, much cheaper than telemetry.

I was having mystery unplanned landings even after changing the ESC and in the end, I just had poor antenna placement for the Tx I was using at the time. I added a sat to the Bx and she stopped falling asleep in the air. When I upgraded my Tx to dx9, I thought didn't need the sat anymore as my other beasts were just fine without one but even from a few feet she started doing it again, and the sat fixed it same as before. I suspect the old 300x's beast is tired, maybe she took one too many dirt dives!

I'm just thinking your issue sounds like your bx gets a hold and shuts down your th?

I really am sorry to post contradictory info than the gentlemen who have shared & helped me a lot already but since the sat is still helping even with the newer Tx I thought it was worth sharing. If your not sure who to listen to, disregard me.

Good luck getting back in the air ASAP!

-=S=-

[C_M_H]

Hey Scream, that Flight Log looks like a great resource. I wish I had known about it earlier.

One thing that makes me think stablehover may be having the same problem as you is the lack of any servo control. I was "lucky" in that I could repeat the problem close to me and the ground, so I could see that I still had servo control....

Awesome info & help here.