CC BEC - Volts and Amps - How do I figure it out?

[Agragor]

Hi all!

Im thinking about upgrading the stock servo on my crawler. I have several times stumbled upon the CC BEC regarding upgrades, so apparently I need one...

The problem is that I'm an epic fail at electronics. Hence me coming to ask you fine people for advice....

Here are the specs of my ESC:

Specifications

Type: Brushed
Constant/Peak: 60A/360A
Resistance: 0.0008 Ohms
Function: Forward/Brake/Reverse, Forward/Brake, Forward/Reverse (Crawler Mode)
Vehicle Type: 1/10 on-road and off-road; 1/10 rock crawler
Operation: Proportional forward, proportional reverse with braking delay, Crawler Mode
Battery Type/Input Voltage: 2–3 cell Li-Po/Li-Fe; 5–9 cell Ni-MH/Ni-Cd
Motor Type 540-/550-size closed endbell motors: 2S Li-Po down to 8T; 3S Li-Po down to 13T
BEC Output: 5V/2A
Overload Protection: Thermal

Here are the specs for the Servo Im thinking of:

Speed(@4.8V sec/60): .18
Torque(@4.8V oz-in): 222.2
Speed(@6.0V sec/60): .15
Torque(@6.0V oz-in): 277.7
Gear: Unique Steel
Bearing: 2BB
Case: Aluminum
Running current (at no load): 100 mA @ 4.8V
Running current (at no load): 120 mA @ 6.0V
Stall current (at locked): 4000 mA @ 4.8V
Stall current (at locked): 5000 mA @ 6.0V
Idle current (at stopped): 5 mA @ 4.8V
Idle current (at stopped): 5 mA @ 6.0V
Limit angle: 200°±10°
Connector wire gauge: ＃22 AWG
Connector wire length: 250 ±5 mm
Horn gear spline: 25T
Control system: Pulse width modification
Amplifier type: Digital Controller
Operating Travel: 100° (when1000→2000 μsec)
Neutral position: 1500 μsec
Dead band width: 3 μsec
Rotating direction: Counterclockwise (when1500→2000 μsec)
Pulse width range: 800→2200 μsec
Maximum travel: Approx 130°(when900→2100 μsec)

The batteries I have at the moment:

4500 mAh NiMH 6-cell flat

My question is: How the **** should I be doing this?


Ok, so apparently my ESC can put out 5V at 2A. The servo seems to need 5A regardless if I run it at 4,8V or 6V so I need to up the power. So in i CC BEC goes...

What voltage should I program the BEC to? If I leave it at the factory setting of 5,1 V I have a maximum of 0,3V left for the motor if the servo goes on full power, so that can't be enough...

If I crank it up to 6V, the servo is covered at full power but then no volts for the motor.

If I set the BEC to 7V will I fry something? Propably with my luck...

How should I be figuring this out?

Thanks in advance!

 

[Agragor]

Perhaps I should have posted this in the newbie section....

Can any Mods move this thread perhaps?

 

[Soldat Vaillant]

what motor are you talking about? your drive motor that powers the vehicle gets its voltage and current from the ESC, it's not powered by the external BEC. you need the external BEC because the on-board/internal BEC in the ESC is too weak, but neither have any thing to do with the motor, its voltage or its current

set your Castle BEC to 6v and enjoy the improved steering from your upgrades

 

[Olle P]

Personally I see no need to spend $15-20 extra just to get the option to fine tune the voltage.
What you need is a BEC that can deliver 5A peak at 6.0V. Those can be had at ~$5.
If you still buy a CCBEC don't be afraid to use a higher voltage, since the servo is designed to be fed straight from a 6V battery (that's 7.0V when fully charged, the actual voltage required to reach 277oz-in).

To connect the BEC you need to:
1. Hook the BEC's input to the ESC's battery connector, so that the BEC is fed side by side with the ESC.
2. Connect the output to the servo. This can be done in three ways:
a) The simple and inexpensive way. Remove the red wire from the ESC's Rx-plug. Connect the BEC to any free Rx-port. Upsides: Free. Simple. No extra cables. Downside: Usable BEC voltage can be limited by limitations in the Rx (typically 7V). The BEC will also feed the Rx.
b) Simple, but slightly more costly: Buy and use an Y-connector intended to connect BEC, servo and Rx. Upsides: Simple, no limits. Downsides: Cost. Added cables.
c) In-between: Remove the red cable from the servo's Rx connector. Solder the red and black output cables from the BEC to the corresponding wires on the servo, and insulate. Upsides: Cheap, if you have the soldering equipment. No limits. Minimum of extra cables. Downsides: Requires some soldering skill.

 

[Agragor]

Thanks for the clarification och tips!

You have really helped me out! Thanks again!

 

[big_poppa49]

Im going to give a X2 on the Y harness setup, That way the ESC is still powering the Rx and the servo is basically running off the BEC directly from the battery. Only thing from the servo that needs to go direct to Rx is signal wire. Although on mine I also left the black wire going to the Rx.

On a side note, a CC 10A BEC is overboard and overpriced. Plus you have to buy the programmer or have somebody else do it. Alot of people I know and things I been reading say a cheap switching 5A BEC is all that is needed. No programming necessary, simply move a pin to get 6v and bam your done. I only run a 2s lipo, so I dont even use a BEC, I just wire my servo direct to battery side of the ESC. But in your case, a BEC is mandatory. I make my own Y harness and extensions, so the cost part didnt really effect me as I have bulk wire, pins and plugs.

 

[Creepcreep]

I struggled with the cost of a BEC for weeks until I could take the glitching no more and just bought one. Since most people are saying not to...I wanted to mention the extreme pros vs the mentioned cons. If you have Savox and Spektrum in the same rig, it cures an infinite number of power leaching issues. Also, if you like lights, you can tune the power going to them so you don't accidentally toast a nice light bar or whatever... Also, my servo sings a much happier song in that rig, and is significantly more "fine tuned" feeling with the addition of a BEC. I don't know a thing about the cheap becs, but I do know that programming is a plus with my cc BEC and if you need a castle link, pm me and ill send you one for zero dolla

 

[Dwill]

Isn't there a coupon in the CC BEC package for a free Castle Link?

I ask because every helicopter CC ESC I've ever bought, and the 4 CC BEC Pros I've purchased for my larger helis came with one.

I didn't even need to send the coupon in, you simply go on their site fill out the form, enter the coupon code and they send the link in the mail.