GWS Top Electric Flight FAQ

☆ Note: If your question is not listed in Top Questions below,

please check other links on GWS Website.



How does a speed controller work?

An ESC (Electronic Speed Control) is a device that controls the speed of the motor by turning the motor on and off. Consider the circuit as a diagram shown.


To turn on the motor you disconnect from its plug with Electronic Speed Controller. If you connect and you stop the flow of current and the motor will slow down and eventually stop turning. Proportional throttle control is achieved by varying the amount of time the speed controller is on relative to the amount of time it is off. For example, for 1/2 throttle, the switch in the speed controller is on half the time.

In order to achieve smooth throttle response, this switching in the speed controller must occur several times per second. Inexpensive speed controllers typically perform this switching 50 times per second. The reason why 50 times a second was chosen is because this is the rate that control pulses are sent to each servo and the electronics are greatly simplified if this rate is used. This is called frame rate because the ESC operates at the same rate as the radio control frames are updated.



How to attach the heat sink to the speed controller ?

Please follow below steps:
1. Cut and tear open the shrink tubing.
2.  Stick the heat conduction silica film to the flat side of the heat sink, then attach the heat sink to the speed controller.
3.  Wear the shrink tubing and use hair drier for fixation.
4. Use a designing knife to cut stripes on the fins of the heat sink, then use the hair drier again.
You may refer to our movie on the below web site



How does a motor brake work?
When a DC motor is spinning with the speed controller turned off it is serving as a generator. With the propeller wind milling the motor (generator now) is producing a voltage at the motor terminals but is doing no work. When you put a short across the motor terminals the motor must now work hard to try to generate the same voltage across a dead short. It might cause the motor (generator) to slow down. The motor short is provided by an electronic switch in the speed control.


How long can I fly once the cutoff function takes place?
We’re sorry! It’s hard to respond you! This depends on several factors and there is no good answer to fit it.




What does the advantage of a High Rate Controller do for us?
This simple responding answer is the efficiency is greatly increased over that of a frame rate control.

An electric motor wants to turn at a certain speed that depends on the voltage that is being supplied to it. Our best speed controller should provide a nice clean DC voltage that varies from a maximum that is the same as the battery down to zero volts.

All GWS electronic speed controllers operate very much like this method.



What is a BEC and how does it relate to the speed controller?
BEC stands for Battery Eliminator Circuit. The battery eliminating is your receiver pack. The BEC is a completely separate circuit from the rest of the speed control. It is generally a one to two amp linear regulator that converts the motor battery voltage to a regulated 5 or 6 volts to power the receiver and servos.



What is a cutoff?
To be frankly with you, a cutoff is a circuit that is added to an esc equipped with a BEC to try to prohibit the motor battery from being run dead and causing a crash when the input voltage goes below 5.25 volts. GWS speed controllers not only have a BEC but have a cutoff circuit. We‘ll highly suggest that you shouldn't use a car type controller in a plane with the BEC active.



Where do I plug in my BEC speed controller?
There will be schemes shown in GWS airplane’s instructions. Please read the instructions carefully and thoroughly before assembly in order to achieve safe operation with the BEC speed controller.



Can I control 2 motors with one controller?

This might be done if you use a sensor controller and the motors are closely matched. It‘s possible to get some problems with the motor initial startup for this configuration. In order to send the correct signals to the motor(s), the controller has to analyze the configuration. Sometimes one motor may fail to start or may even start in reverse. There is little that can be done about this other than to cut the throttle and try again.



About ESCs, BECs, and servo failure ?

After a number of in-flight failures of the same type of servo under different conditions, I started a thread in another vendor forum asking for help:
Servo failures—what's going on?
In that thread, a number of people have wondered if and how ESCs used under certain (recommended and non-recommended) conditions may have contributed to servo failures without themselves being damaged (i.e. a servo fails, but the ESC is undamaged). That thread seems to have reached a point where more insight on the functioning of ESCs and BECs would be very helpful.

Here are the two set-ups:

1. Pixie 7P, 3 micro servos, 3s lipo, dual IPS ~2 A average draw
2. Phoenix 10, 3 micro servos, 3s lipo, CD rom motor ~ 2 A average draw

In the first case, it has been rightly pointed out to me that the BEC on the Pixie 7P is overloaded with 3 servos on 3s lipo. What would the expected failure be in this case?
In the second case, it is my understanding that the ESC and BEC were not overloaded. Or am I missing something?
It is well worth pointing out that my one and only goal here is to avoid future crashes from servo failure!

I think that servos can be damaged if BEC fails and feeds not 5V as it is designed to do, but full battery voltage-11.1V with 3S LIPO for example.
If it is overloaded(as in too much amp draw from servos with too high voltage) -BEC will shutdown, or loose voltage output to servos, then you loose control of your aircraft. But I don't think that voltage going low can damage servos.
So if you are continuing to use your ESC's and no more servos died it would mean that BEC output is in normal range, you could measure it with voltmeter to be sure.
CC representatives will give you better explanation I hope, as I am not sure how exactly BEC shuts down

Not to stray from Andrew's initial question, I'd like to know the different ways a BEC can fail and the consequences of those different BEC failures. Whether natural or user induced. David

#1 set-up - you are correct, it is simply out of spec and will not work at all, or for long. The BEC chip will be almost constantly overheating and shutting down, until the point of failure (closed circuit) with no output.

#2 is fully within specs, and does not pose an issue for even the BEC to shut down from overheating at all, UNLESS a servo is stalled, or the pot is damaged/partially burned/has dead spots and so on. Even good small servos when stalled can draw surprising amounts of current, and with pot damage can basically be a direct short.

The only real (or induced) damage any controllers BEC can cause (we all basically use similar linear regulator circuits) would be from providing less than 5v in an overheating and shutting down situation. Mike from Hitec would know if a constant shutdown-reboot cycle would do anything negative to a servo. From what I know about them, I don't see how it could be harmful#1 set-up - you are correct, it is simply out of spec and will not work at all, or for long. The BEC chip will be almost constantly overheating and shutting down, until the point of failure (closed circuit) with no output.



I just completed GWS Spitfire and a ICS300 speed control. #1 there were no instructions how to install the heat sink. #2 all the controls work fine but the prop stops turning in a short while.If I wait just a very short time, it will run again but only for a short time and stop.I am using the same prop and motor that came with the kit.There are several in our club that are preparing for racing. I have learned from a fellow at the hobby shop that the timing of the motor can done to increase rpm. Is this correct? If so, how do I do it?

First of all,  cut the shrink tube and put the heat sink on the back side of ESC (front side is ESC label) . Now install the new shrink tube which has enclosed within the product, then use the hair blower to shrink the tube.  Furthermore, please refer the website



I would like to use a Li Poly battery with the  ICS-5 controller.  Is it safe and what is the auto cut  voltage for this controller?

Is ICS-5 a mis-typing of ICS-50? There is the spec of ICS-50 on,
please check. We do not recommend ICS-50 to handle Li-Po battery because ICS-50 is a 2A speed control. Depending on the capacity of your batteries, you might need a larger amperage speed control.