Speed Controllers The speed controller is the unit that will distribute the power from the battery to the rest of the you radio controlled aircraft electronics. It also controls the amount of power to the motor for more or less speed. If the amperage reading on the motor is 30 amps on burst, you will need to look for a speed control with at least 40 amps. It is very important that the capacity of your speed controller is greater than the burst amperage of your motor. This is to protect the motor and the rest of the radio controlled model aircraft electronics.
The speed controller has a battery port, motor port and a signal cable. The battery port is where the battery will be connected to it has a red cable and black cable. Red is positive and black is negative.
Please note that it is very important to get these terminals connected correctly if you swap these connections around you will blow the speed controller and maybe even the rest of your electronics.
The Motor ports contain three cables positive, negative and a signal cable. With these connections you cannot blow anything but this will determine the motors direction and whether you will be using a pusher or a puller. This means if the motor is in the front of the plane it will be a puller and if it is at the back, it will be a pusher.
The signal cable is a thin cable with a connector on the end that will go to your receiver. Normally this will be channel three on the receiver. To set up the speed controller, you will need to look at the instructions that come with the speed controller. Do not worry, there will be instructions that might be a bit overwhelming, and you may not understand what they mean. Most speed controllers are programmable. This means you can set up custom setting for your speed controller depending on what you require.
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Low voltage protection is when you run out off battery power in flight then the speed controller can gradually reduce the power to the motor, or you can set it to cut the power completely to the motor. This is not suggested because if the speed control cuts power completely, you will have to depend on height and wind to bring the aircraft safely to the ground, but this will ensure that you do not draw too much power out of the battery not to harm the battery.
If the speed controller is set to gradually reduce the motor power, it will gradually slow down the motor and thus reduce the risk of completely depleting the battery. This will help to get the aircraft safely to the ground before your radio controlled model aircraft runs out of power totally.
Low voltage protection threshold is to tell the speed controller at what voltage it needs to start reducing the power output to the motor. Rather set this to medium. If set too low you risk damaging the battery. If set to high you will cut down your flight time.
Startup mode is how the motor reacts when you push the throttle stick from still to full power. There is normal, soft and super soft. At normal the motor would react almost instantly. If set to soft or super soft the motor would take time to get to full revolutions. Normal is used for most radio controlled model aircraft, and soft or super soft is used for radio controlled model helicopters.
A great function to set is the brake function. This stops the bade from spinning in the air. This function works well to reduce the amount of drag that the motor will have if you are not using the motor for example gliding or coming in for a landing.
High, medium or low timing is a function that works with the type of motor you are using in your current application. This is the pole rating on the motor if it has 12 poles or more you have to set the speed controller to high timing. If the motor has 6, 8,10 poles, you have to set the speed controller to medium timing. If the motor has less than six poles, you have to set the speed controller to low timing. This also determines the power usage of the motor. Some motors are not compatible with some speed controllers. The poles we talk about are actually the magnets on the motor so they can be counted if the motor does not give you the specifications.
Battery type is the type of battery used to power your airplane. There are a few different types of batteries the default is li-poly or Li-ion.
This is a slightly edited and updated version of an article originally published on “Fly Strong Model RC Planes” – fly-strongmodelrcplanes.com