I had this exact same issue earlier this week with my EMax 30A BLHeli ESCs and my Emax 2205s; the motors would stutter a bit, but if I ramped up hard to full throttle, it would spin up. Kill the throttle, and it would shut off and start stuttering again. Turns out it was the timing; I had inadvertently changed it when trying to recalibrate the ESC throttle range. My problem was exactly as
@Hai-Lee indicated - stuttering due to timing.
I would HIGHLY recommend setting it to the defaults and starting there; make sure only one is plugged in at a time when you start trying to program. Once it's programmed and calibrated, you can connect both up to the receiver.
There are two ways to program the ESC via the transmitter:
Select program parameters
Hold the throttle stick on top position, there’re 7 parameters can be set by using your transmitter. You would hear 7 different indicating sounds which correspond to 7 different parameters. Pull the throttle stick to the bottom position (full Off throttle) within 2 seconds after you hear the correspondent sound will brings you to the correspondent parameter setting status. The indicating sounds will repeat in turn as follow.
1. “beep-” (a short sound) which indicates the Brake Type
2. “beep-beep-” (two short sounds) which indicates the Timing Mode
3. “beep-beep-beep-” (three short sounds) which indicates the Start Force
4. “beep-beep-beep-beep-” (four short sounds) which indicates the Curve Mode
5. “beep-----” (a long sound) which indicates the Control Frequency
6. “beep-----beep-” (a long sound and a short) which indicates the Low-voltage Protection
7. “beep-----beep-beep-” (a long sound and two short) which indicates the Cutoff Mode
8. “beep-----beep-beep-beep-” (a long sound and three short) which indicates the Rotation Direction
Select program values
After entering parameter setting status, hold the throttle stick on the bottom position, you will be led to the repeat selection of that parameter setting status. Each sound likes 4 short sounds and one long sound (1 long sound=5short sounds), and by that analogy. After some sound, pull the throttle stick to the top position in 2 seconds, after you hear a tune “♪3 2 1 ♪3 2 1”, which means the correspondent value has been chosen and saved. Hold the stick on the top position, return to the second step and continue programming.
D. Programmable parameters
D1. Brake Type: There are two options: OFF, ON. The default is OFF.
D2. Timing Mode: There are five options: Low: 0°, Mid-low: 8°, Middle:15°, Mid-high:23° and High:30°. The default is Middle: 15°. Low advance timing is recommended for high inductance and low KV motors. High advance timing is recommended for low inductance and high KV outrunner motors. For some high KV motors, if it shakes while rotating in high speed, the High timing mode is recommended.
D3. Start Force: There are 13 options: 0.031, 0.047, 0.063, 0.094, 0.125, 0.188, 0.25, 0.38, 0.50, 0.75, 1.00, 1.25, 1.50. The default is 0.75. Select the corresponding start force according to the load of motor.
D4. Curve Mode: There are 4 options: OFF, Low, Middle and High. The default is OFF.
D5. Control Frequency : 2 options: 8KHz and 22KHz. The default is 8KHz. This option is the drive frequency of the motors.
D6. Low-voltage Protection: 4 options: OFF, 2.8V/cell, 3.0V/cell, 3.2V/cell. The default is 3.0V/cell. the system will automatically identify the battery cell. E.g. suppose there’re 3 cells, if the voltage is lower than 9V, the system will work according to the current cutoff option.
D7. Cutoff Mode: There are two options: Soft-Cut and Cut-Off. The default is Soft-Cut. Soft-Cut option: Gradually reduce throttle power to 31% of the current power when the voltage is lower than the programmed low-voltage protection threshold. Cut-Off Option: immediate motor shutdown occurs in low-voltage.
When low-voltage protection, Push the throttle stick to the bottom position and then to the top position, the motor will be restarted. But since it is low-voltage condition, the output power is low or stopped at once.
D8. Rotation Direction: There are 3 options: Normal, Reverse, Bidirectional. The default is Normal.
Exit program
Pull the throttle stick to the bottom position within 2 seconds and hold on after saving parameters, until you hear a tune “beep----
beep- ♪ 1 2 3”. Set the Min. Throttle at this moment and exit program and operate as normal.(beep----means Loading parameter. beep- beep- beep-means numbers of cells and ♪1 2 3 means ready. )
There is also the method to reset the ESC to factory defaults:
Restore Factory settings
To restore Factory settings, pull the throttle stick to the bottom position (full Off throttle ) within 1s after entering program mode (Step 1)→Pull the throttle stick to the top position within 2s, then you will hear a tune, which means that the factory settings have been restored. Pull the throttle stick to the bottom position within 2s, the ESC is ready with factory settings.
If the Bidiretional mode is chosen, the Minimum Throttle actually means Middle Throttle position. Factory settings can be restored under Bidirectional mode.
I would recommend setting the ESC to factory defaults first, and then testing it. Odds are, that's what the issue is.
