E5 Servo upgrade

[Wolf51]

Hi guys,

my E5 is still going strong and great fun to fly.
Thinking I may do a stretch conversion in a few months time.

But right now I'm looking at replacing my existing servos.
Currently flying Align 615 cyclic and 655 tail, moving to BK7001HV and Futaba BLS276SV

Is anyone using BK7001HVs on their E5?
I'm curious about whether there are any problems with getting them to fit on the airframe.
I'm pretty sure the Futaba will fit in the tail spot ok.

cheers

[Jason Cummings]

I have them in mine with no shimming or issues.

[Wolf51]

Thanks Jason,

that's what I wanted to hear.

How are you powering yours, BEC or flight pack?

[Rodney Kirstine]

I'm running those on my E5 and N5C.  On my N5C, I can get 8-10 flights on a 2550mah flight pack.

[Jason Cummings]

I went to hv servos so I could run a 2s lipo.

[Aaron T]

I run BKs in all my synergy's. Great fit, fast servos. Hard to beat the price. Been reliable for hundreds of flights too.

[Wolf51]

Thanks for the info guys.
Its good to get positive feedback about the BKs from some fellow E5 owners.
This will be my first upgrade since I built the heli, it should be interesting getting to fly with some stronger servos.

I'm currently running 6S with a Castle BEC Pro and will continue with that for now.
I plan to change to a 2S lipo flight pack in my 12S stretch project, though finding a good location for the pack looks like being a challenge.

[Rodney Kirstine]

I run a CC BEC pro on my E5SS, mounted on the bottom side of the ESC tray.  I have it wired to one 6S pack with an EC3 connector so that I can power up everything except the ESC when I'm working on it.  I have the output set to 8V and I am also using the BK coreless servos.  I've got a ton of flights on this setup.

[Wolf51]

Thanks Rodney,

I've had good work out of my BEC Pro as well, lots of flights no problems.
I also run a Scorpion backup Guard and it helped me save the heli recently when the main pack stopped delivering in flight, but that's another story.

Now, I thought running the backup guard alongside the BEC Pro was ok, but recently re-read the BEC Pro user guide and saw this:

NOTE: CC BEC Pro should never be operated in series or parallel with another BEC or backup receiver pack connected to the RX/Servo side of the circuit.

I'm not sure why this is a problem for the BEC, but the Backup guard is necessarily connected direct to the receiver in parallel with the BEC.

After the experience of losing the main pack in flight I'm very conscious of the benefit of having backup power for the flight control system in case main battery or BEC fails.

So while I'd be happy to continue using the existing setup, and the system still works following the recent incident, I'm wary that the BEC may fail or be damaged by the backup guard and cause other problems down the line. And that's why I'm thinking of switching to a LIPO flight pack.

[Cliff Chmiel]

I'm running the bk servos in both my e5s and my e7se with no problems at all

[troasb]

I am still running the Align 615/655's in my E5 and after some 300+ flights have not felt the need for something better. I am running Align 815/855's in my N7 and they seem to develop slop faster that the 615/655's. I guess the reason is that 615/655 have titanium gears, while 815/855's seem to have steel gears.

[Mike Spano]

the issue with the backup guard and the bec is the possibility of backfeeding. and yes, it can cause your bec to fail. it happened to me with a hurcules bec a few years ago. a fellow was trying to help me make some adjustments to my fbl unit. instead of plugging in my flight pack (12s on the e7se), he pulled what he thought was my bec lead from my flb unit and plugged in a 2s pack into my fbl unit. he didn't know I had 2 plugs coming from my bec, and before I knew it, the bec was fried.

I fly OMG cyclic servos on my helis. fast, strong, and reliable. tons and tons of flights on my helis. you cant beat the brute strength of the OMG servos.

[Wolf51]

Thats it Mike,

I contacted CC tech support and they confirmed their recommendation not to use a backup battery with the CC Bec Pro, due to the possibility of damage/failure due to back voltage.

That said, I've used the Scorpion backup guard with mine for about 9 months and it hasn't caused any problems for the BEC, yet!  And that includes maintaining power to the FBL so I could auto the heli when a power lead on the flight pack desoldered in flight (increased resistance in a connector caused it to overheat). Saved a potentially big repair bill. I've flown the heli since and the system is still working fine.

After that experience I'd rather not use a BEC powered control system without backup power.
It is possible to install a bec guard between BEC and FBL to stop back voltage, though that inserts another potential point of failure in the system.
Using a 2s lipo FBL/receiver pack means I could do away with the BEC and the backup guard.
A much simpler system and only requires that I charge and check the condition of the 2S pack.

[Mike Spano]

honestly, I think its more of a problem with the Hercules line. I know tons of guys that use them with Castle Creations BECs with no problem, despite CC asking people not to. but that Hercules bec fried the instant it was back fed, literally. lol

that same guy that plugged the 2s into mine said he did it to his all the time with no issues (he was running a CC BEC Pro).

please don't misunderstand. I am in no way telling anyone not to listen to CC and their recommendations. please by all means follow what CC recommends.....

[Mike Dipalo]

I pulled a fried herc apart this year. Older model, not sure if the design is unchanged.

The way the system has the control FETs hooked up means it'll go bang if external power is applied to the output without the unit first being on.

CC BEC from what I could tell (haven't pulled one apart yet) will be alright, however there may not be safeguards in place to deal with sensing, line priority, etc.

Easiest way? 2s LiFe pack or LiPoly. Doesn't need to be huge and heavy. A little 2.2Ah pack is fine for a wad of flights and they are cheap.