How do I use a BEC in B400?

[sd0]

Whant kind do I need to buy? Is it like my Trex600 where it has a seperate battery?

I just installed hs-65mg's on cyclic, and I'm about to put either a 401/3400g or a HG-5000/5083mg or a SolidG/3400g on the tail, and I have read that when you upgrade servo's and gyro you need to run a BEC or you will have power problems.

What BEC, and how do you hook it up?

Thank you for any information/help you can give me.

[LockMD]

I use the SportBEC for 30 bucks. I soldered in at the ESC's connector. Then plug the ESC into the BEC and the BEC into the throttle spot on the rx flip a switch to run in 6V and your done.

[SeaComms]

I used a helihobby uBec, again, solder the input to the main battery conections of the ESC, then I removed the red wire from the current ESC connector on the receiver and just plugged the uBec into the battery socket on the receiver.

Picked it up off ebay for about $15 shipped.

And just found this when looking to answer for someone else - a picture is worth a 1000 words as they say..

http://www.castlecreations.com/images/ccbec_wiring-large.jpg

[Wolfpackin]

You probably don't need the external BEC because you are running analog servos for cyclic.

The problem arises from using a total of four digital servos which are the big amp drawers.
The gyro really doesn't effect things as the amp draw is low, usually around 10-20mA's.
Your 65MG's probably draw around 0.5A.
The big question will be the draw of the 3400...could be around 2A's I'm not sure on that one.

SeaComm's,

Did you go with a BEC because you had problems with your setup or just for insurance?

My plan is to go with the HS65's, and a small digital on the tail, with no external BEC.
I guess I'll see how right I am.

[sd0]

Just test did a test flight/hover under the streetlight outside my house, still with the stock gyro and tail servo.

Damn, there is a huge difference, when you let go of the cyclic stick, the 65mg's center every time instantly. With the stock servos when i used to center the cyclic stick, the helicopter would continue to go off in a random direction. Not sure if it was the servos or the factory setup, I never checked anything out till I put in the new servos. But when I did I saw how off the factory settings were, swash was nowhere near level, pitch range was positive 14, negative 6. I should have checked this out a long time ago.

It flies so much better now, can't wait to get my new gyro and tail servo in there.

Well, I hope that me and all of you have a crash free weekend of flying.

Good luck and thanks again for all the help. You guys are the S**t.

[SeaComms]

SeaComm's,

Did you go with a BEC because you had problems with your setup or just for insurance?

My plan is to go with the HS65's, and a small digital on the tail, with no external BEC.
I guess I'll see how right I am.

Just for insurance sake as it was only half the price of a servo I reckon its cheap insurance. I had a few hovers with the stock setup and the ESC was very warm to the touch - could only just hold finger on the heatsink, then all stock but with the uBec it was very noticeably cooler, only just warm.

Have put the HS65's in and have the 5000 / 5083 combo on its way. then I have to try and manage to keep it in the air! Still awaiting an answer from the supplier as to the radio glitch, hopefully will get an answer on Monday but will most likely have to send the TX and RX back in.

Have had this damn heli for nearly a month now and only had 3 decent hovers so far!!

Arrived in Mode 1 not Mode 2 as requested - that took a week to sort out
A few hovers and not really controlling that well, dumped it a few times
Then discovered one servo over driving under load, the cause of the lack of control
Now have new servos installed and while fine tuning notice a repeatable servo glitch that looks like a TX or RX issue...

SHEESH!!!!!!

[eugenefelisco]

[quote=Wolfpackin;628474]You probably don't need the external BEC because you are running analog servos for cyclic.

So I don't need external bec at the moment coz I'm using hs-55 in my cyclics for now. And yes indeed it made a whole world of difference, now I'm convinced the stock servos are faulty after rebuilding them a couple of times already.

My progress in the backyard after a week of hovering with gear, today for the first time I took the gear out and what a nice hovering machine. Now its a heli now coz mine not like the other never hover out of the box so alot of twicking happened in a month I had my 400.

So keep on fying and have fun.

[SeanOC]

how many amps is the stock ESC's internal BEC rated for?


I've been running 3 65mg's and 1 9257 with the stock gyro and esc with no problem so far..

[SeaComms]

The stock internal BEC is rated at 3 amps. However, it is a linear regulator not a switchmode. This means basically it disapates excess energy in the form of heat to keep the voltage at the rated output. The big problem comes when it gets too hot, combined with the heat being generated by the ESC, causing the whole package to overheat and momentarily shut down or brown out, causing the receiver to reset. On the later version receivers this is only momentary, but the earlier versions will take up to 5 seconds to reboot and link up to the transmitter - certain death for a heli. Hence my decision to go for an external BEC. The cheapy I chose is a switchmode, 5/6 volt switchable and rated at 3 amps continuous 5 amps peak.