joewisconsin

Hi,

I'm currently looking to create a set-up where a motor - Castle Creations NeuMotors 1915/3Y is ultimately driven by a manual control - for instance a knob that would control motor speed. I'm having problems understanding where a BEC would fit into this application. I have no other servos/additional loads that need power, just the motor. Could I just pick an ESC that fits the amperage and does not have a BEC? If so, how do I control the ESC without a receiver? I've been looking at "servo drivers" but I believe these are for controlling servos with the BEC, not for controlling the motor. Any help or a point in the right direction is appreciated.

Thanks,
Joe

dirtybird

My Feedback: (5)

For your application you will not need a BEC.
A servo driver will work just fine. It has its own power supply

joewisconsin

So for instance I could go with http://www.castlecreations.com/produ...e-lite-hv.html for the ESC, and then http://secure.hobbyzone.com/cel1410....Fe1cMgodKEUA-Q would just get plugged into it? Sorry if this is very obvious, I am not familiar with RC at all. I am also looking at two of these: https://www.hobbyking.com/hobbyking/...arehouse_.html in series to make it 12S as the power supply to the motor. Thanks, Joe

Rob2160

Hi Joe,

What is the application? I can give you better advice and if I know what you are trying to do with the motor.

Dirtybird is right, if you are not driving servos or a receiver you don't need a BEC.

You can buy an ESC (Electronic Speed Controllers) with or without built in BEC (Battery eliminator circuit)

A servo controller will work just fine for controlling the ESC.

and yes you can put those batteries in Series to a form a 12S supply, no problems there.

dirtybird

My Feedback: (5)

12 cells mean nearly 50 volts. Your ESC is going to be expensive.

joewisconsin

The application is to power a hydraulic pump for up to 5 minutes of continuous operation at full power. The pump/motor combo is taken care of and something I understand. The motor/controller and that area is where I am not so sure of what I am doing. The idea is to have the motor at variable speeds controlled by a knob to increase/decrease the speed of the pump. Minimizing weight as much as possible is what ultimately brought my search to the RC world.

Rob2160

Thanks Joe, understand now.

Just checked the Motor and it runs at 1800 watts. (Surge to 3600 watts)

With 12S (around 50 Volts) you will need an ESC that can handle 12S and 60 amps. (80 would be better)

As for controlling it. The servo driver you listed will work but requires a separate 4.8 volt power supply (a typical RX flight pack like one of these )

If the ESC has a BEC then it will power your Servo Driver and you won't need the separate 4.8 volt pack.

Hope that helps.

chuckk2

This unit has a digital display that allows you to determine the control pulse width as well as controlling the pulse width.
With that info, you might consider a building a custom circuit to generate the pulse train.

http://www.emsjomar.com/SearchResult.aspx?CategoryID=6

joewisconsin

Thanks for all the help and explanations. After some looking, this is what I think I'm going to go with, let me know if it's a good/bad idea or if you know of less expensive or lighter-weight options. Heat build-up is also a concern, I'm looking at running at full-load for approximately 3 min on/1 min off cycles for multiple cycles, this could/would include battery changes if necessary. Are there any simplified ways you folks use to do a thermal analysis?

Thanks again

Phoenix Edge Lite HV 80: http://www.castlecreations.com/produ...e-lite-hv.html
CC BEC Pro: http://www.castlecreations.com/products/ccbec.html
Turnigy Servo Tester: http://www.hobbyking.com/hobbyking/s...vo_Tester.html
with
Batteries: 2x https://www.hobbyking.com/hobbyking/...arehouse_.html to make a 12S

chuckk2

Remember that airflow across the motor, ESC, and battery is usually needed for cooling.
Some of the ESC specs show a minimum airflow.
R/C car models often have a fan that cools the ESC heatsink.
R/C planes usually make use of the airflow in flight.
Take the battery "C" ratings with a grain of salt. I usually use a 30C or better rated Lipo,
The 5000mah 6S lipos that I use with 75 to 90A ESC's are rated at 30C to 45C.
Using Lipos at or near the continuous "C" rating cuts the life expectancy.