servos causing brownout?

[jdjohnson]

Got a question for you guys. I'm stumped and not quite sure what to do. So within the last week my blade 450x v2 has lost motor power mid flight three times! Every time its during flips and basic 3d. Sport flying it doesn't seem to have a problem with. When I lose power to the motor I'm still able to move my servos so its a softer crash. Great time to learn autos lol. Anywho I've got stock servos still with probably 500+ flights on them. My guess is that one of the servos is spiking? Causing my esc to shut off power supply? Here's my setup on the heli,
Phoenix edge lite 50
Built in bec on esc at 5 volts
Scorpion 2221-8 motor
5 3cell batteries. Around 2400mah 25 -30c
Stock metal servos
Thanks for any advice you might have!

[learnedthehardway]

I'm still a total noob on the 450x but what I read about a brownout is the beastx shuts off and has to re-initialize. So my guess would be if you were having brownouts you would not still have control of the seros when it occurred.

Sounds like you may have a bad motor connection, or some other issue between the motor and esc.

[Mattinfla]

One of my friends had this exact same problem on his 450x. The culprit turned out to be the ESC. The BEC circuit was dropping below the 7200bx minimum voltage, and it was rebooting.

Matt

[learnedthehardway]

If the v2's servos are rated up to 6v then you can set the bec for 6v operation for a cushion. Maybe that aftermarket motor is sucking too much juice, maybe something is binding causing a spike. Hard to say

[gstoneberg]

Have you checked the log on the ESC? That's where I'd start looking.

[Gyropilot]

JD,

See if you can induce a brownout on the AR7200BX on the bench. With all the blades removed and throttle hold on, really work all the servos hard for a full minute. To do this, grab the collective (throttle) stick on the Tx between two fingers and work it up and down as fast as you can while also moving the stick side-to-side to work the tail servo. Some guys also recommend putting a bit of pressure on the rotor head to load up the servos.

My setup is a little different than yours (I have more electronic crap), but when I did this to my 450X I was easily able to induce repeated brief brownouts in my Spektrum remote receiver. The logs in my Castle Edge Lite 50 showed nothing was wrong, but the telemetry logs in my DX9 showed the receiver voltage was briefly dropping below 4 volts.

I installed an external Castle 10A BEC which solved the problem.

Good luck,

John

[jdjohnson]

Thanks for all your help guys! Much apprechiated So I think I've figured out what's going on. My elevator servo linkage is binding with both the swashplate and ail servo linkage! I've tried adjusting the elevator control lever. I've not figured out how to adjust it and make it work any other way than the current spot it's in now Any advice on how to eliminate this binding? Heres a couple pictures, ones of it hitting the swasplate so hard it actually bows the link, and then theres the ailron servo it's hitting, and it makes a pop noise when they grind together. Thanks for your help again guys!

[jdjohnson]

Hmm, now I'm super confused. So I tried changing the internal bec in the phoenix edge lite 50 from 5v to 6v. I just took it outside and tried to take off, as soon as I left the ground I lost control of my heli and it went up ten feet or so then lost motor power and I was able to land it softly. Any ideas? And now that I think about it this is the second time I've tried 6v bec on this esc and the last time it lost power too. I know I've got the metal servos so I don't understand. Thanks guys

[GregCA]

Originally Posted by jdjohnson

Thanks for all your help guys! Much apprechiated So I think I've figured out what's going on. My elevator servo linkage is binding with both the swashplate and ail servo linkage! I've tried adjusting the elevator control lever. I've not figured out how to adjust it and make it work any other way than the current spot it's in now Any advice on how to eliminate this binding? Heres a couple pictures, ones of it hitting the swasplate so hard it actually bows the link, and then theres the ailron servo it's hitting, and it makes a pop noise when they grind together. Thanks for your help again guys!

This binding is one of the "features" of the stock frame. Make sure the setup is good in BeastX menus G, J, and K then try to limit the cyclic ring in menu L to reduce the binding. I usually find I can't eliminate it completely, but it only occurs with full positive collective and forward elevator so it's usually not an issue in normal flight.

[jdjohnson]

Hmm well that's kind of a crappy design huh? So would me binding it up like that cause the brownout? I'm thinking maybe it causes a power surge?

[Gyropilot]

What's the log file from the ESC showing when the motor stops?

Specifically, is the throttle input signal changing?

Is it showing steady battery and BEC voltage?

[jdjohnson]

Well as far as I could tell the voltage and throttle input both look solid throughout the flight. When I get off work today ill try and post a screenshot of it. Any idea why setting the bec to 6v would cause such trouble?

[Gyropilot]

JD,

If it's not over 2MB, just attach the entire .csv data file to a reply so we can pull it up and look at it using CastleLink Graph Viewer.

John

[Tim Wolff]

Originally Posted by jdjohnson

Well as far as I could tell the voltage and throttle input both look solid throughout the flight. When I get off work today ill try and post a screenshot of it. Any idea why setting the bec to 6v would cause such trouble?

Turn the sampling rate all the way up on the ESC. More frequent sampling will increase the chances of any intermittent issues being captured in the log. Make sure you add the BEC voltage to the paramaters logged.
If you have servo control, the RX is not browning out. The BX AND the ESC will both go to low throttle on signal loss. The BX will hold position on the servos until signal is regained. A through range check with heli in all orientations is in order.
Double check the motor wires and reflow the solder connections.
As already suggested run through the Beast X setup to minimize or eliminate the binding.

[gmiller0]

I agree with Tim... Did you change placement of anything lately? Here is what happened to me:
Satellite Placement https://www.helifreak.com/showthread.php?t=705731

[Tim Wolff]

Originally Posted by gmiller0

I agree with Tim... Did you change placement of anything lately? Here is what happened to me:
Satellite Placement https://www.helifreak.com/showthread.php?t=705731

Mine was on my 300x after I zip tied the longer RX antenna neatly to the CF boom support. Motor wire check, new ESC, a bunch of broken parts...all solved by cutting a zip tie.

[gmiller0]

Tim, what do ya mean "cutting the zip tie?" Did the zip tie damage the rx sat wire or was the carbon fiber "blocking" the signal?

[jdjohnson]

Here's the castle link log. I believe it is session 14. Thanks for your help with this guys I truly appreciate it. Just getting off work, gonna look through your comments again and try a few things.

[Tim Wolff]

Originally Posted by gmiller0

Tim, what do ya mean "cutting the zip tie?" Did the zip tie damage the rx sat wire or was the carbon fiber "blocking" the signal?

Silver part of the antenna didn't like being tied to the support boom.

[jdjohnson]

So I followed your guys's advice, I went through the beastx setup and adjusted a few settings to help with the binding. It has helped, however I still have the linkages hitting each other etc. So I'm just gonna stay away from full positive pitch and elevator. No biggie
I also changed the sampling on the phoenix edge lite to 10 per sec, still not seeing anything new, no spikes of energy or dropout on signal. Also, I never moved anything or changed any parts, it just started doing it on it's own lol.