Versacopter V2 ... motor or ESC problem?

[badSpartan]

Hi there. Yet another noob looking for troubleshooting help!

My Versacopter worked flawlessly for several months until I had a bad crash and rebuilt. Ever since the rebuild, it will only fly using my 3S battery. I have 2 other batteries which are 4S. When I try flying with a 4S battery, it stays in the air for 20-30 seconds each time, and then gradually loses power and descends. It doesn't flip over, but comes down in a fairly quick but controlled descent, regardless of how much throttle I apply. Once it's on the ground, the motors continue to spin at minimum idle, however they do not respond to any throttle input. I can disarm and then re-arm, and then it takes off no problem, but repeats the same thing, losing power after 25 seconds. However using the 3S battery, it flies fine. I've tested each battery and they appear fine.

Thinking that it was a motor issue, I've replaced 2 motors. One motor was completely damaged from the crash, and the other was sputtering on startup. This hasn't resolved the issue. Could it be a damaged ESC? But why would it function normally with a 3S battery. Does the higher voltage from the 4S cause it to fail?

Any advice would be greatly appreciated! Thank you.

Versacopter V2
Emax 2204-2300
Naze32 rev6
Cleanflight
Lumenier 3s & 4s
Taranis X9D+

 

[Jugsy]

Sounds like it could be the voltage, does anything get hot immediately after it comes down?

 

[badSpartan]

thanks for the quick reply.

no, i've checked both motors & esc's, and neither gets unusually warm.

another thought i had was that it could be the pdb, but there's no visible damage to it. after the crash i found a broken solder joint where the battery connects to the pdb. i re-soldered that joint, but could it be that i just didn't solder it well enough? it appears to be rock solid. i can't move the joint at all.

grrr ... i just replaced the esc's and now i'm not getting any power to the naze. i must be missing something obvious. the original esc's were from the FT powerpack E. these new esc's are Little Bee 20A. do they behave differently than the originals in terms of supplying power to the FC?

 

[Cluteeaye712]

I don't think the littlebee escs have a built in BEC (Like the BLHeli 12A escs in the FT power pack) to provide 5 volts to your the flight controller, so you'll need to run a separate BEC or 5V Pololu step down regulator to take your flight battery voltage down to 5 volts and power the Naze board. If the ESC's only have two wires going to the flight controller, thats the case. I have also had rthe same issues with the power pack E running 4S, the motors are not technically rated to run on 4S, though FT claims they do.

 

[badSpartan]

thanks for the info Cluteeaye712. i didn't know about BECs. i guess i'm learning something new every day!

 

[Cluteeaye712]

Happy to be able to help, honestly! Thats one of the reasons I love this hobby, I'm learning stuff every day as well. Cheers!

 

[Dippeggs]

Hey just wanted to say I have the same exact problem with my Versa! I was using Power Pack E as well. Used a 4S till the very same thing happened to me. I think it was a mixture of the ESC's not having enough amps and the motors are rated for 2-3s only.

 

[f91ddr]

thanks for the info Cluteeaye712. i didn't know about BECs. i guess i'm learning something new every day!

Here's something else:

If your ESCs have a BEC built in, you MUST disable all but 1 of them if they the switching type. Linear BECs don't have a problem being connected in parallel (all the + and all the - are connected to each other on the flight controller board), but the switching BECs will fight each other and most likely break themselves or something else if used together.

I have Turnigy Plush 30A speed controllers on my tricopter, but lucky for me they used linear regulators so I didn't have to do anything special.

 

[badSpartan]

i finally bought myself a Pololu 5V stepdown to power the Naze32. just looking for some info on how to connect to the Naze. I'm guessing that you just solder the board into place using the included pins, and then run a wire from the + and - Aux_Pololu pads on the Versa PDB to an open port on the Naze? again, i'm guessing that's the idea, but don't want to risk frying my FC. anyone done this before? a pic would be great!

 

[PsyBorg]

I'm not positive what the problem is you guys are having but I can say for a fact that the motors in the recommended power pack from FT for the Versa copter CAN run 4s. I upgraded to their 30 amp esc's and have been running 4s every day. The motors and the esc's actually run far cooler on 4s then the do on 3s. granted I am using 6x4.5x3 now with the 3s and only 5x4x3 on the 4s as I couldn't find 5x4.5x3 at the time I made the swap.

 

[badSpartan]

yeah mine ran fine on 4s for nearly 4 months and then all of a sudden one day that stopped.