RX battery needed in 450 electrical heli?

[terjeau]

I need to post a stupid newbie question:

I have a Spektrum DX7 (only), and I have ordred a AR6200 RX.
I will order the elektrical HK-450 (www.hobbyking.com) T-REX 450 clone (including cheap HXT900 servos - Voltage : 3v ~ 6v).

Do I need a RX battery, or will the big lipo feed the RX and servos?

If it is needed, what do you recommend for my setup (type, voltage, model - preferable from hobbyking's store)?
I suppose a NiMH will be better than a permanently mounted lipo due to charging safety and more suitable voltage

[RocketSled]

You don't use the Rx battery. The ESC provides power to the Rx, the Rx provides power to the Servos and Gyro. The ESC guarantees a motor cut-off voltage that's high enough to ensure the Rx continues to run to the point that the motor shuts off (after which, the Rx will probably still work, but it doesn't matter since you've landed).

[Jermo]

I've been using the stock ESC that came with my Align 450SEs to power my AR6000 and AR7000 recievers. I've not had any issues. I think there is a potential issue on larger choppers with brownouts and such.

[TJinGuy]

Technically a bec supplies power to the rx system on a 450, not the esc. Many escs have a built-in bec. Now sometimes you use the built-in bec and sometimes you use a seperate bec. That all depends on the esc.

[jacs]

Hi,

The stock HC 450 you need to change some part to align parts to get it to fly well, but this is only what I'm been told so it might not be right. Battery you attach with velcro and switch after flight with a new one. They should be round 3S1P 2200mAh 25C to be good. Then use a 40amp esc also otherwise you will burn it since the 3700kv motor use like 30+ amps.

[824TSV]

The only time you would possibly use a separate battery to power the Rx is during your build. It's easier to use a 4.8 volt battery to power the receiver when your setting up your servo's. This way you don't need to have the esc and lipo connected. This is the way Finless does it on his servo set-up video and the way I did it as well.

[Jermo]

Originally Posted by TJinGuy

Technically a bec supplies power to the rx system on a 450, not the esc. Many escs have a built-in bec. Now sometimes you use the built-in bec and sometimes you use a seperate bec. That all depends on the esc.

Technically the stock ESC with the 450 has a built in BEC as you state. I was stating I had used the stock ESC/BEC with zero issues on the 450.

Keep it simple stupid - KISS

[akshaw]

The specs for your esc should say how many analog/digitial servos the internal BEC can handle, and what the output voltage is. So, if you decided to run all digital servos, it may turn out that the ESCs BEC can't handle the load required and in that case you would want to go with an external BEC. Another thing to take into account is what voltage range your servos and gryo can run on. It's usually better to try to go with a BEC which produces an output voltage that falls within the range specified for all servos and gyro.

[seanh]

rx battery- 4.8v is fine on the 450. This you could plug directly into the rx or you can go with 7.4v but you would need a regulator and not a BEC. Many, many people including the hobby companies such as Align get this wrong. BEC stands for Battery Eliminator Circuit. What is it for...so you don't need the extra rx battery pack. In fact Align finally realized this and now is properly labeling their regulators...Wrongly called external BEC before.


If you decide to use a separate rx pack and you want to use the same ESC, you'll need to cut the power lead (not the signal lead). You can't have 2 power sources on you rx...not this one anyway.

need parts...check out hobb e mart on ebay. They regularly have blade cp's that have bad esc's or receivers for 50 bucks or so. http://stores.ebay.com/Hobb-e-Mart?_rdc=1

get a bunch of feathering shafts, main shafts, belts, you'll need them. If you stick with stock motor and esc...keep about 5 of each on hand. But in my opinion it's better to just convert to brushless.

keep busting blades? get some plastic ones like these...don't remember if you need 235 or 275, both are available.

http://cgi.ebay.com/Super-Durable-Pl...item53dedd8e35

if you are having problems getting gyro setup or balanced let me know, I'll offer any help I can.