Written by Webmaster
When I got into flying electric planes, one of the first tasks I came across was programing my speed controller. I soon realized that some models and manufacturers have different options and settings. Most of them came with an instruction booklet (or a slip of paper), but didn’t really give great detail as to what each setting meant. I had to go to many differerent websites to find all the information I was lookign for. Setting a speed controller correctly will make your electric flight experience much more enjoyable.
CastlelinkThis is a typical interface for the Castle Creations CastleLink software. Most of these features are only available on Phoenix speed controllers.I have reviewed some of the major speed controllers on the market and made a list of the settings they offer and what does the setting mean for you. Not all speed controllers have the same options so you might see many features that aren’t included with your speed controller. Some companies use different terminology for similar features so I tried to use generic terminology to describe each feature.
Many budget speed controllers do not offer many of these features. After reading through this list hopefully you’ll see why a particular feature is desirable. Castle Creations Phoenix speed controllers seem to have the most programmability features when you use their CastleLink software to program the speed controller through the USB port on your computer. Many of the features a Phoenix speed controller can do aren’t accessible through conventional programming (such as using the transmitter).
If you aren’t sure how to set certain values such as the PWM (see table), you can always contact the manufacturer of your motor and ask them what settings you should use.
Voltage Cutoff The cut off voltage is set to protect Lithium Polymer batteries from being over discharged which will damage the battery (less than 3v per cell). I prefer to set my voltage cutoff to 3.2v per cell for lipos. This gives me a small buffer ensuring I don’t ever go below the maximum discharge of 3.0v per cell. If you are using NiMh or NiCd batteries you do not need a cut of voltage to protect the batteries, as these types of batteries will quit flying your aircraft long before they are discharged to zero. If you are using more than 6 NiXx batteries set your cut of voltage to 5 volts. If you are using 6 or less NiXx batteries set your cut of voltage to 4 volts.
Cutoff Type Changes the behavior of how the ESC reduces voltage when the cut off voltage is reached.
Hard Cutoff -When the battery pack reaches the cut off voltage it’s set for, the power is cut off to the motor (the BEC power on controllers with a BEC is ALWAYS on and powering your radio system, and is a completely separate system than the low voltage cutoff setting). You can throttle off and back up, and the motor will restart, but the motor will cut off again if you throttle up to the point where the voltage drops below cut off voltage. This is recommended for airplanes, and it provides the best protection for your batteries. Note: If you are getting cut off before your batteries are drained, or before reaching full throttle, it is a good indication that your batteries are not up to the power demands of your system.
Soft Cutoff – When the pack reaches the cut-off voltage, power to the motor is reduced until the pack voltage rises above the cut-off voltage. Power is then continually modulated to maintain the cut-off voltage. The motor will appear to hunt for a set speed, and slowly have less and less power if held at full throttle. This is recommended for helicopters and 3D flying or if you really hate dead stick landings. In either case, a sudden loss of power is unwanted when the cutoff point
Direction When you power up the motor for the first time, if it spins in the wrong direction, you can change the direction using this method instead of having to switch two motor wires. This allows you to solder you controller to the motor without worrying about having to re solder. (This setting can be changed without any risk to the controller or the motor.)
Motor Start (Acceleration) Power This setting will control how much power is allowed into the motor to get it started for the first few revolutions from a dead stop. Each power system, airplane and heli is different, so it’s best to start with a low setting first, and experiment to find which looks best to you from there. Setting a small delay will help with geared drive systems.
PWM (Pulse-Width Modulation) Rate This setting changes the frequency with which the controller sends power pulses to the motor. With some motor types, the higher the frequency the more efficient the motor will run, but always at the expense of increased heat within the controller. If you decide to experiment with changes to PWM, use a wattmeter, a tachometer and a temperature gun to find out how changes affect your entire power system. An increase in PWM frequency will always increase the controller temperature. It may or may not decrease the temperature of the motor.
Throttle Response This setting controls the allowable rate of change from one throttle level to another. The higher the response, the less dampening there is for changing throttle levels. The lower the response, the throttle may feel “mushy” or slow to respond. Higher response levels make the throttle response quicker related with throttle changes.
Motor Timing Motor timing advance settings changes the timing advance range used on the motor. Generally, low advance gives more efficiency and less power, high advance gives more power at the expense of efficiency (motor heat). Every system will respond to changes in advance differently. If unsure the motor timing you should use, leave this to “Auto” or whatever the default setting is set for.
Current (peak) Limiting This setting changes how the controller protects itself from too much current, or inadequate batteries. Generally, for aircraft use, there is no reason to change this setting except to experiment. Helicopter use can put large but short load spikes on the system, and will benefit from changing this to either insensitive or disabled (to decrease the chances of the controller turning the motor off). However this will increase the risk to the controller from over current. Using a battery of too low a discharge capacity can sometimes engage this protection feature by creating ripple current. If you are getting premature cutoffs, and changing this setting to disabled cures them – look closely at your pack and connectors to be sure they are adequate for your application.
When the prop is locked or jammed and the motor stops running, the ESC will stop power to the motor immediately, so the motor can be protected from damage due to over-current. If you disable this feature, use care to make sure your prop is never jammed or locked (such as a really bad landing).
Temperature Overload Protection As the name implies, when a speed controller gets too hot, it can go into protection mode to prevent heat damage to the controller. Since this feature turns off the motor just like a LVC or over current, it could be hard to verify which problem is actually turning off the motor.
Governor Gain This is applicable to helicopter setups. This setting works the same as the gain on your gyro. Too little, and the governor rpm response can appear mushy, and too much can induce oscillation. Generally, the larger the heli, the higher the gain for crisper response.
Brake Allows you to fine tune the brake for specific applications. The brake has two primary uses, to stop a folding prop on a glider to allow it to fold and to control downlines in 3D and precision aerobatics. Glider pilots should experiment to find which brake works best for their application. Brake Strength changes brake strength from soft (weak) to hard (strong) braking.
When the propeller turns after shutting down throttle the rotating magnets set up an EMP which gives resistance thus trying to stop the propeller from rotating. This might stop the motor, but large propellers could still rotate because too much power from the propeller in the airstream. This function is especially for assuring folding propellers will fold back on motorgliders, hotliners etc.
Brake Delay Brake Delay changes how long the brake takes to engage after full off throttle.