Xxtreme 800 wiring issue

[Highflyer028]

I just finished wiring my 800 per the manual and per Mr.mel's new YGE OEM video. At first everything seemed normal but then i noticed the gyro sensor flashing very quickly and noticed the vbar itself was very hot. I unplugged the batteries and now my vbar does not work. I dont understand what could have went wrong. I am using the Western Robotics BEC hooked up to only one of the 7s packs. Same exact wiring setup i do on all my helicopters. When i plug a 2s lipo into the vbar it doesnt do anything but when i unplug it i see a flash of red on the gyro sensor. Im guessing its a failure message. Any ideas of what could have gone wrong?????

[rcmarty]

The neg of the bec has to goto the first 7s pack - the first pack neg connects to the esc.

Otherwise if you take the black of pack #2 then you put 22 volts extra into the system and fry it all


Safest thing to do with the WR bec is connect it to 14s , very hard to get it wrong.

I've read another post on this , they guy did kill all his servo's.

https://www.helifreak.com/showthread.php?t=428497

Martin

[Highflyer028]

I did something like that. I shorted the system. Servos seem ok. I think the vbar blew and saved my electronics. I'm going to replace the receiver and BEC just to be safe. Only thing I havnt been able to check was my brand new YGE 160. Crossing my fingers it didn't get it. How I have it connected it should of only got the 14s connection. I think the short shot straight to the BEC and vbar.

[rcmarty]

The previous post where the guy had his bec wired wrong , i don't recall if they worked or not still.

He sent them in to have them checked out along with a note saying what he did.

The service rep called him up and said he wouldn't trust them either, Rep also said at least replace the board. He was lucky as the rep said he could have new servo's for the price of the boards because he was being honest about the situation.

Thought i'd share that with you. It's a hard lesson to learn as the good servo's are so expensive.

On the other hand a servo failure and a crash on the logo 800 is worse. I've heard of 2 crashes so far , one at 1000 and another at 1200. I ended up changing to futaba myself.

Another note worth considering.

I recall a thread about BEC's and the good high powered servo's of today.
They were able to get the 8.4v down to 2.4 volts for a split second (using a scope), good quality WR bec.

Discussion continued on with the bec's that have battery backup, redundant batteries ,extra caps , then battery only comments.

What i got out of it is that these super servo's that are out there can even take down a WR bec for a split second ( if the split second was long enough to reboot vbar or receiver/sats wasn't explored to far) and that is cause for concern.

I concluded that the simplest method is to use a 2s lipo to power electronics (hv servo's)

Next up is the BEC but with a battery backup/buffer. The battery is there to get the bec thru any peak demands without alowing the voltage to drop.

Last up was the bec with a big cap bank. Would make for a hell of a spark on connection , but 'should' be able to make it thru the peak demands.


On yet another thread these same power hungry servo's are shutting down bec's with back emf ( jive esc set to 6 volts with align/savox 610 servo's )


I'm not trying to talk you out of a bec , just want you to know what i've read and food for thought. ( or random rambles )

On my 800 i run a 2s4000 lipo (old 16 tp cells) and recharge at 4 flights (800-900mah). Montior with the WR colour changing lipo monitor. I feel safe i can get thru high demands ( jr 8717 ) from the servo's with a capacity that far exceeds my requirements. Weight on a 800 is very minor consideration.
My smaller machines like my logo 6003d , i run the built in jive bec set to 5.6 volts and futaba bls451 (not heavy draw servo's ).

I'll be honest , babysitting another lipo isn't on the top of my list but a 1000+ crash is insentive to do it.

Hope this is of some help.

I hope your electronics are good , i'd suggest they get checked out. the 800 is an awesome machine , would hate to see you have a servo failure.

Martin

[rcmarty]

To check the yge just plug long lead into a receiver , power up receiver (no bec in esc) and give it a try.

I checked for rotation on my 700 build that way , even used a dead 6s pack.

Martin

[Highflyer028]

So if it appears to be working I should assume it is ok? Kinda nervous now.

[rcmarty]

Originally Posted by Highflyer028

So if it appears to be working I should assume it is ok? Kinda nervous now.

The esc ?

I would be less concerned about the esc myself.

It's a non powered (bec ) unit so the direct connection to power ( center red pin ) isn't connected. It accepts a signal input from the vbar , granted im no expert in the signal department but i assume there isn't alot of power within that signal (ms pulse) assuming it even had an output ( vbar fried when voltage applied )

The rpm sensor uses the ground reference and a pulse from esc.

The + 22 volts on the ground is the wildcard here.

I'm not promising it's good but in theory it should be far less likely damaged.

Lets hope some more electrinic savy guys pitch in an opinion.

Martin

[rcmarty]

Definiely some easy upright testing to be done first assuming your at the auto stage. Hard upright climbs to load test esc

Martin

[Highflyer028]

Thanks! I am going to get everything checked out. Better safe than sorry.

[rcmarty]

Yes , thats a good idea.

Sorry i'm not bringing good news , but adding a crash to unfortunate situation isn't going to help either.

I will say that it's an awesome heli after 60 flights and i wouldn't part with it.

Martin