hi,

My setup is as below:

Walkera #36
Stock radio and gyro,
Align 420 brushless motor with align 25A ESC
2x futaba servo, 1x hitec servo, 1x walkera stock servo.

Since a major crash, I could only hover for about 5 sec before the motor stops, this is on a fully charged lipo. Don't really know why, but think it could be the ESC cutting out due to BEC under voltage???

Does anyone know what could be the problem? do I need a second BEC and can I just buy one and install it with the Align ESC BEC??
Or has th ESC had it?

Thanks in advance.

Andrew

Most likely you need a BEC. I made the mistake in telling myself I didn't need one, right before a crash with my SA. Needless to say, I ordered a 5amp BEC the same day. For your setup, a 3amp BEC will do just fine. Don't listen to anyone that says you don't need a sepererate BEC. Both my 25amp and 35amp align cutoff on me, even just for a split second, and the last one was disasterous. These ESC's come with crappy BECs that were designed for very light servos of 3 or less running on an FM only receiver. I don't even think they handle more than 1 amp of current before they starve the ESC of it's own power to process signals. Get a good BEC or crash. Hope it works out.

Thanks for the reply, if I'll get a second BEC, how do I install it with the existing ESC and its own BEC. Can both BEC be used at the same time? I assume the second BEC will be installed on a spare channel.

Thanks,

Andrew

My understanding is that with most BEC's you just tap your battery power and plug the BEC into a channel and you are done, at least that's what everyone at my LHS says to do. The BEC will take most of the load off the ESC at this point, but I imagine that the ESC may still supply some power to the circuit. If you got a higher voltage BEC, like a 6v, then that would almost eliminate the ESC from supplying power because it's output voltage would be less than what's on the line (current can't flow out of the ESC BEC) and the external BEC would be feeding everything. I suppose you could remove the 5v line from the ESC with no harm done. I would follow the directions that come with the BEC.

Were does one get a BEC O looked on Tower Hobbies web site and dint find one. I know going to An LHS would be the easiest but i live in a town that has no LHS and the closest one is 50 miles away. So were can i find one on the internet.

This is one I bought off Tower and received it today:
[link=http://www2.towerhobbies.com/cgi-bin/WTI0095P?FVSEARCH=sbec&FVPROFIL=++]http://www2.towerhobbies.com/cgi-bin/WTI0095P?FVSEARCH=sbec&FVPROFIL=++[/link]
I got the 5amp one and installed it and it works great. It has adjustable voltage and also has a low voltage buzzer that's adjustable. Interestingly the instructions said to disconnect the power line from the ESC connector, so I did. The instructions said it could handle up to 11 digital servos so I assume the 3amp would do just fine for $24.

that is great thank you i will get the 5 amp for my heli.

What version of the ESC do you have? Is the heat sink glued to the heat shrink tubing? If so, you have one of their poorly designed units and just another BEC probably won't fix the problem. The electrical shielding on these is ungrounded and very susceptible to electrical noise, which can result in unexpected cutoffs for a fraction of a second. Also, they tend to overheat. I just "redesigned" my Align 35A, and it has stopped giving me problems. If you have the bad version, I can give you more details on what I and others have done.

Yes, tell, o tell, please do.
Pictures too.