What BEC should I use

[Kindling Maker]

What Bec is a good one to use? I have been Looking around and I am not sure what voltage I should get. I am getting ready to order it and I am not real sure. I have been on Helihobby and they have a bunch of BECs and I need some help on deciding.

[sokal]

castle seems to be the choice of many able to do 6 volts
small size and easy to use

[skigolfmike]

I have the Castle ccbec and I really like it. However, you need the Castle Link ($22) to change the voltage to something other than 5.1V. If the bec is the only thing you are looking at getting from Castle right now, you might want to look at something else.

[LockMD]

I'll vote for SportBEC 25 bucks - can go up to a 6S battery - can set at 5 or 6V and you dont have to cut any wires to install. I have installed it on my 600 too.

[skigolfmike]

I used a separate 2S receiver battery (7.4V) on my Guai 550 with a Spektrum step down for the TR servo. My CCPM servos are wicked fast with this setup.

LockMD: what servos do you have on the 600 and what is the amp rating of the BEC? One of the things I discovered setting up the 550 was it was easy to overload the BEC. For example, the CCBEC is a 10A BEC, but that's only peak Amps with a 3S (11.1V) batt. With a 6S it's 5A. The DS8717Gs I have on CCPM draw 2A at idle and the TR servo DS8900G is an amp hog also. There was no way one ccbec was going to cut it (needed at least 2) so I went with the receiver batt and a step down for the gyro and TR servo.

I'm still at 5.5V with the ccbec on the B400. I may jump it up to 6V just to see if it makes a difference. However, it flies pretty good now. I'll have to shoot a new video and put it up.

[LockMD]

Mike, as you know I DONT know about this electricity stuff so PLEASE tell me this is okay. Here is the SportBEC: http://www.dimensionengineering.com/SportBEC.htm

And here are the servos:

https://www.unitedhobbies.com/UNITEDHOBBIES/store/uh_viewItem.asp?idProduct=3880

I actually fried the one on the tail trying to run it in digital mode so I have those 3 on the cyclic and an S9650 on the tail.

[LockMD]

del

[SeanOC]

Hey guys,

I just upgraded my heli with 65mg's on the swash and a 9257 on the tail. First off am I ok running the 9257 at 4.8v (stock, right?) and second am I gambling by not running a BEC? Not sure what the 9257 draws.

Thanks!

Sean

[skigolfmike]

Mike, as you know I DONT know about this electricity stuff so PLEASE tell me this is okay. Here is the SportBEC: http://www.dimensionengineering.com/SportBEC.htm

And here are the servos:

https://www.unitedhobbies.com/UNITEDHOBBIES/store/uh_viewItem.asp?idProduct=3880

I actually fried the one on the tail trying to run it in digital mode so I have those 3 on the cyclic and an S9650 on the tail.

IMHO, the specs on the BEC for a Trex 600 are weak. Output is only 3.5A, your TR servo gyro might be able to pull that all by itself. What I would do is get a separate receiver pack. I got a FlightPower 1345mAh 2S pack, which will get you 4+ flights between charges. I can get 5 flights on the G550 out of mine on a full charge and I have killer servos.

I couldn't get to the website with the servo specs here at work, so I don't know about the CCPM servos.

[LockMD]

okay but I am not building a rex 600 but an E-Smart 600 and here are the specs on those servos:

Metal gear with bearing.
This is a fast, accurate and strong competition servo.
Weight: 48g / 1.058oz
Torque: 9.7kg-cm 132oz/in
Speed: .12sec / 60deg
Size: 40.5 x 20 x 38.5mm
Gear Type: Metal Gear
Ball Bearing:Single Bearing at top.

Do not mistake this for a cheap servo. This is a fast, accurate and strong servo used for competition use without overheating.

[skigolfmike]

I take it these are digital servos. Then I believe what I said before still applies.

Figure your TR servo and gyro are going to be in the 2-2.5A range, then you have the receiver and the other servos too. If they are digitals, then they pull about 1-2A each even at neutral, so you're looking at a 5-10A radio system. I don't believe a 3.5A BEC is going to cut it.

[LockMD]

Nope not digital, that's how I burned one up tried to run digital mode on the tail.

[skigolfmike]

Then you might be OK. It's going to be close though.