Trex 600e with BEC and rx pack

[mountaindewdude76]

I was given a Trex 600e Pro DFC, with a bunch of "bells and whistles". It has the CC ICE2 80HV ESC (obviously BEC OPTO). It has a CC BEC Pro and it has a set of wires, with a Deans plug, for an rx pack. I've used my rx pack to power the rx and servos so that I could get it programmed and setup. I haven't plugged in my flight pack yet. I have rc planes that have external CC BEC's (because the ESC is opto), so I do have some understanding what the BEC does and all.

My question is this....why would my 600 be wired up with a CC BEC Pro and an rx pack? There are pro's and con's to each individual setup but I'd much rather have the rx pack to power the rx and servos.

Any thoughts?

[pril250]

I am a believer inj separate power for the electronics and servos. you can use anything between 2S 2200-3600mah RX pack and any BEC 6-10A. Remember to cut the red wire from the ESC 'throttle' so you get only speed control and RX power from the BEC.

[mountaindewdude76]

Well, essentially, don't the BEC and the rx pack do the same thing? I just don't understand why I need both.

I have several rc planes that have ESC's that are BEC OPTO, so I run an external BEC, but no rx pack.

[nightflyr]

CCBECPro when wired to a 6S pack will give you the maximum available current if you are running HV servos.
It can be run off a separate battery pack to supply power to the Rx( redundancy ) , or run a Rx pack directly into the Rx.

It will all depend on your setup and requirements.
Any of the above will work.

[Smoggie]

First thing.. Please ignore previous advice to cut the ESC red wire. If you do that on an OPTO ESC the ESC wont work at all because it wont have any power on the LV side of it's circuitry.

I guess the set up had the BEC Pro powered off a separate battery pack but as you say, that's rather stupid. The best option is to power the BEC Pro directly from one of the 6s main flight packs, but you must connect the black wire of the BEC to the ground wire of the flight pack, and the red wire to the jumper wire that joins one pack to the other. There is a wiring diagram on the Castle web site.

You can only run a 2s LiPo direct to the Rx if you have all HV servos. The standard Align servos aren't HV.

[pril250]

Obviously if the ESC requires the power to operate then ignore the cutting of wires advice, thanks G_O_M for highlighting this.

[mountaindewdude76]

Originally Posted by Grumpy_Old_Man

First thing.. Please ignore previous advice to cut the ESC red wire. If you do that on an OPTO ESC the ESC wont work at all because it wont have any power on the LV side of it's circuitry.

I guess the set up had the BEC Pro powered off a separate battery pack but as you say, that's rather stupid. The best option is to power the BEC Pro directly from one of the 6s main flight packs, but you must connect the black wire of the BEC to the ground wire of the flight pack, and the red wire to the jumper wire that joins one pack to the other. There is a wiring diagram on the Castle web site.

You can only run a 2s LiPo direct to the Rx if you have all HV servos. The standard Align servos aren't HV.

Yeah, I'm not gonna go cutting any wires, lol.

In fact, the description that was given in the second paragraph is exactly how my 600 is setup with the ESC and BEC. I think. This is what I have:

The red wire, from the CC BEC Pro goes to the positive prong on the Deans plug for the rx pack. The black wire goes to the negative prong on the Deans plug for the rx pack and then there is a black "jumper" wire that goes from the negative prong on the Deans plug to the negative wire of the CC 80HV ESC.

My biggest question is: why would I need the BEC if I'm using the 6.6v LiFe rx pack?

Perhaps I'm over-thinking this and just confusing myself.

[pril250]

For a 6.6V LIFE pack you wouldn't need a BEC, you could feed direct, you would if you were using 2S LIPO (7.4V) especially if your servos are not HV's.

[mountaindewdude76]

Originally Posted by pril250

For a 6.6V LIFE pack you wouldn't need a BEC, you could feed direct, you would if you were using 2S LIPO (7.4V) especially if your servos are not HV's.

Ok. That's what I was thinking. Thanks guys!

I imagine that the original owner, possibly, had HV servos and then swapped out the HV servos for the stock servos when he sold it. Good enough for me.

I appreciate the clarification!

[Smoggie]

Is a LiFe pack safe on all 6v servos? LiFe packs are 7.2v fully charged and run at 6.6v normally. Seems like you might be pushing a servo rated for 5-6v pretty hard with those voltages?

[mountaindewdude76]

Hmmm, I just checked the voltage specs for the Align DS610 and DS655 servos. You are right GOM...they are only rated for 4.8-6.0 volts. Perhaps this is why the CC BEC Pro is wired into the mix...possibly to step the voltage down.

How would I go about finding out, so that i could be sure? I imagine that I should be able to hook up the Castle Link to the CC BEC Pro and use the programming to show me the settings that were stored originally. Remember, this helicopter was given to me...so I'm simply learning as I go. On top of all that, I've never flown anything larger than my 500...so this will be a huge learning experience...and it has been.

[pril250]

In any event running a BEC acts like a voltage regulator meaning the selected voltage remains constant as long as the input voltage does not fall below and that it can cope with the demand of current. I prefer running with a 2S as that fully charged is 8.4V and goes down to 7.4V at cycle end.

To protect your servos from overheating in this case the BEC selected to output 6V will be a safe advantage.

I have read of guys running those servo directly on LIFE packs with no adversities but if you want to remain safe...

[mountaindewdude76]

OK...this is starting to make sense to me now. I just hooked up the Castle Link to the CC BEC Pro and it is set for an Output Voltage of 6.0 volts. This BEC is wired into the mix to bring the voltage down to the 6.0 volts. I have been using a 6.6 volt LiFe battery for setup and programming and I had intended on using it for when I take this 600 out for it's first flight.

However...I spoke with a buddy of mine earlier today. He has a Trex 700e that is basically wired just like mine (with minor differences) but he runs a 2S 7.4 volt 3600mah lipo and he's using the Align voltage regulator to bring the voltage down to 6.0 volts Now....no matter if a fully charged 7.4 volt lipo (8.4 volts roughly) or a 6.6 volt LiFe battery (7.2 volts roughly), the CC BEC Pro will bring that voltage down to the 6.0 volts so that I don't overwork my servos but I should also have a constant 6.0 volts being delivered, in either case.

From the sounds of it, maybe I should set aside my LiFe rx pack and get a 7.4v lipo for an rx pack.

Am I understanding this correctly?


...and just so that it's well known...I fully believe in safety and I try to be as safe as I possibly can. This is why it's taken me so long (nearly 6 months) to get this helicopter in the air. I wanted to understand what was happening so that I could be as safe as possible.

[pril250]

You do understand this correctly

[mountaindewdude76]

Outstanding! It was quite confusing, until about 20 minutes ago. I just didn't understand why my 600 has the external BEC and an rx pack. I didn't even think about the voltage possibly being too high.

I had actually intended on removing the CC BEC Pro tonight but I didn't do anything to it until I was sure. Now I'm glad I didn't remove anything

Thanks a lot guys! You really helped clear things up for me and you helped me learn something. I appreciate it! Chances are, you all probably just saved my helicopter, lol.

[nightflyr]

FYI ....
With your setup you should have no issues.
I have a few machines setup that same way and have had no problem.


But, I also have a few that run a LiFe directly into the Rx ( AR7100 ) that have ALIGN 610s on cyclic and still operate with no issue.

Even on a 800 class machine no issues


As I said ... all depends on your setup and equipment requirements

[Smoggie]

Originally Posted by mountaindewdude76

I had actually intended on removing the CC BEC Pro tonight but I didn't do anything to it until I was sure. Now I'm glad I didn't remove anything .

Yes, the set up you suggest (2s LiPo feeding CC BEC Pro) will work fine and will deliver a safe 6v to the servos.. However you dont need the 2s LiPo. You can perfectly safely power the BEC Pro directly off one of your 6s flight packs. This saves the cost and weight on the 2s LiPo plus it means that you cant forget to charge it!

I run my BEC prop in exactly that way on the 600 in my signature, it works great. Voltage at the Rx is in the range 5.8-6.1v at all times, even under highest load.

[Gladius]

In a 12S setup, if you wire your BEC to pull power from one of your lipos, does it drain that lipo more than the other?

I also have the stock Align voltage regulator on my 600 ESP. Will that work as a BEC? Is the Castle Pro BEC better, and how so?