SOMETHING NOT WORKING!!! :(

[nerdnic]

Klinger RC
Is there a clue in the video?
When one motor cut out the other significantly speeded up suggesting that with both motors running the battery voltage is sagging badly. Add a servo current as well (particularly if the surface is not really free moving) and the battery voltage drops to a point where one of the ESCs hit its LVC as nerdic pointed out.

Do the controls continue to work when one motor has cut out? If an ESC has hit the LVC the servos should continue to work normally.
What capacity battery are you using and its C rating?
Do you know the current the motors are taking?

If you run the motors at very low power does a motor still cut out if you move a servo?
Can you test it with a bigger capacity battery to ensure the voltage does not sag.

This was my second thought. If he's using the AH set up as stated then he'll need a battery able to push about 20a. The battery seen in the video appears small and I'd be surprised if it was bigger than 500mah.

 

[Klinger RC]

Yes, the servos continue to work after one motor cut out and the control surfaces move freely. I'm using a 800mah 20c lipo. This should be capable of putting out 16A right? When I just run one motor with the servos, everything works fine. Neither of the motors cut out. I noticed that when one stops, it beeps three times. Th esc also does this when I plug in my three cell lipo. The only problem I have with the idea that it is hitting LVC is that the manual says lvc goes to 50% throttle. Could their be something else that is causing the esc to stop and re-initialize?

The 3s 800mah 20c lipo should give out about 16amps of power. I have a 2s 800mah 30c and a 1300mah 20c lipo which both should give about 24amps. Do I need to change to one of these batteries, or get an even bigger one?

 

[nerdnic]

Does the issue happen if you stay at 50% power on both motors?

Please try with the 1300mah also. The C rating of a battery is usually inflated and running a battery at its max capacity will always cause the battery to drop significantly in voltage. The beeps you hear are the esc rebooting like weve said many times. You may not be hitting LVC, you might be completely starving out the esc.

From what you've told us and what the video shows it's pretty clear your battery is not providing enough power. Please use the bigger battery and we can keep looking if there is still an issue. Also invest in some voltage alarms for your batteries, they are 2 dollars and beep when a cell hits a specified range. It will help keep you from over discharging and also to troubleshoot in times like this.

 

[PhenomPilot]

I think you nailed it nerdnic. Both esc are in lvc with both motors running until one esc gives up and the other esc comes out of lvc. The servo movement draws enough power to get the one esc to give up and reboot. Sounds like it is going to need a bigger, newer or higher C rated battery.

 

[RichB]

How hot are the wires between the battery and the ESCs getting? I see you are using a battery with a JST connector. That means you bought some JST whips somewhere. I've seen them come with wire as small as 22ga


edit: never mind. I see that this was covered earlier.

Can you wire a volt meter into the harness? I winder if that battery is toast.

 

[Klinger RC]

The battery I was using is fine and I'll order some more, higher c rating batteries soon. Thanks for all the help and Merry Christmas!

 

[Tritium]

That Y harness looks really long, and fairly small gauge. It looks like there's enough of a voltage drop to cause a brown out on the ESC. Both motors at full power could be pulling a fair bit of current through that cable.

Uh....NO! Motors do not "Pull current" through the ESC control wiring (rather, only the POWER wiring)! The ESC may "supply" power to other devices via the control cable but it is usually an amp or less so no issue at all.

Thurmond

 

[nerdnic]

Uh....NO! Motors do not "Pull current" through the ESC control wiring (rather, only the POWER wiring)! The ESC may "supply" power to other devices via the control cable but it is usually an amp or less so no issue at all.

Thurmond

In the video there is a really long Y harness using JST connections for the battery to ESCs section - I believe this is what is being pointed out, not the signal wire.

 

[quorneng]

Just a point but when I do the initial ground system testing on multi engine planes I use a big capacity battery (with its equally big cables) to ensure battery voltage drop is not an issue.

 

[Klinger RC]

we have a problem. I bought a bigger battery (3s 1300mah 35c) and it still cuts out!!!!!!!!!!!!! I have NO CLUE what is wrong. The same thing is happening a was before.

 

[mikemacwillie]

In the video there is a really long Y harness using JST connections for the battery to ESCs section - I believe this is what is being pointed out, not the signal wire.

Yep, that's exactly what I was talking about.

we have a problem. I bought a bigger battery (3s 1300mah 35c) and it still cuts out!!!!!!!!!!!!! I have NO CLUE what is wrong. The same thing is happening a was before.

It'd still bet it's in your power wiring. Put a volt meter across the supply leads at the ESC if you can, and see what kind of voltage drop you're seeing. The beeps it makes indicate that it's resetting. Another thing to check would be that the supply capacitors are still attached at the ESCs. If one of the leads is broken at the ESC, you could see MCU resetting at higher currents.

 

[quorneng]

There could also be a bad connection (extra voltage drop) or even an 'loose' one that momentarily breaks connection causing the ESC to reset. With t props removed and motor running work along the wiring giving it a good wiggle to see if you can provoke a motor to cut out.

As pointed out you need to rigorously test with just one motor and ESC connected and then the other. If either motor still cuts out then the problem is most likely not the ESC or motor but in the wiring somewhere.

 

[Klinger RC]

I shortened up the y-harness and ran both motors seperatly, the each worked fine. I ran them together, full throttle and moving all the servos, and everything worked fine! Thanks guys! Now I'll go back to repairing the guinea from it's crash.