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Fig 4.
Let’s go to the Tab labeled “Motor”. “Motor Start Up power” not a real critical item - medium is a good staring
point. Do be careful that it is not too low, as problems with power on takeoff will manifest themselves. You
should be at full power at 12-15 feet after start of role. This function also interrelates with “Initial Spool-up
Rate”.
“Motor Timing” The ICE controller uses an advanced timing method where the timing is adjusted automatically
based on load and RPM. The way the principle designer (Patrick del Castillo) suggests setting our timing is… “I'd
suggest you bump the timing up slightly from "low" (using custom setting) until you get the power you want.
The lower timing will give you a much more efficient and cooler running system (less wear and tear on the
motor too!)”
What you see is my end result; I went from Custom (2) and stepped up incrementally to Custom (4). “Medium
(5)” equates to approximately 18 deg from ZCO (EMF crossing zero). I have heard the guys in the Czech Republic
recommend 12 deg so a setting of 2-4 is somewhere in the right area.
“Direction” this is self explanatory.
“PWM Rate” set to 8 KHz but others have used 12 KHz successfully. 8 KHz is the most efficient settings for a
medium size outrunner. The general rule is the lower the motor’s inductivity, the higher the switching
frequency should be. Increasing the switching frequency reduces the ripple in the current flow in part-load
mode; but at the same time causes a rise in eddy current losses in the motor and switching losses in the
controller. These losses do create heat in both the motor and the ESC. So if you run a higher PWM frequency
expect to spend a little more current and generate a little more heat. As rule of thumb for selecting PWM for
the motor - try this formula – Motor Kv x Magnetic Pole Count of the Motor x Nominal Volts used then divide by
a factor of 20. Then round the answer down to the nearest setting on the ESC PWM Rate.
1) Motor Kv 760 x Magnetic Pole Count 14 = (760 x 14 = 10,640 )
2) Times Nominal Volts 18.5 vDC = (10,640 x 18.5 =196,840)
3) Then divide by a factor of 20 = (196840/20 =9842)
4) Round down 9842 = 8000 or 8K