Motors hot after short hovering


#1

I have just finished building a 110mm quad and have noticed on the first few flights that the motors are getting quite hot, even after a very short hover. I have spent a bit of time PID tuning and it seems to have reduced the temperature a bit, but I’m still a noob and don’t really know how to tune properly.

Can anyone give me an idea of whether this is a problem, or something that can be tuned out, or should I just not worry about it.

Here is the parts list:

  • GEP-HX2 Hummingbird Quadcopter Frame
  • MiniCube F3 Flight Stack
  • BrotherHobby Returner R3 1106 5100KV
  • Turnigy Nano-Tech 460mah 3S 25~40C Lipo
  • RacerStar 2035 4-Blade Propeller
  • Betaflight 3.2.3

Here is the dump from Betaflight

set align_gyro = DEFAULT
set gyro_lpf = OFF
set gyro_sync_denom = 1
set gyro_lowpass_type = PT1
set gyro_lowpass_hz = 90
set gyro_notch1_hz = 400
set gyro_notch1_cutoff = 300
set gyro_notch2_hz = 200
set gyro_notch2_cutoff = 100
set moron_threshold = 48
set align_acc = DEFAULT
set acc_hardware = AUTO
set acc_lpf_hz = 10
set acc_trim_pitch = 0
set acc_trim_roll = 0
set align_mag = DEFAULT
set mag_hardware = NONE
set mag_declination = 0
set magzero_x = 0
set magzero_y = 0
set magzero_z = 0
set baro_bustype = SPI
set baro_spi_device = 1
set baro_i2c_device = 0
set baro_i2c_address = 0
set baro_hardware = AUTO
set baro_tab_size = 21
set baro_noise_lpf = 600
set baro_cf_vel = 985
set baro_cf_alt = 965
set mid_rc = 1500
set min_check = 1010
set max_check = 1990
set rssi_channel = 0
set rssi_scale = 41
set rssi_invert = OFF
set rc_interp = AUTO
set rc_interp_ch = RP
set rc_interp_int = 19
set fpv_mix_degrees = 0
set max_aux_channels = 14
set serialrx_provider = SBUS
set sbus_inversion = ON
set spektrum_sat_bind = 0
set spektrum_sat_bind_autoreset = ON
set airmode_start_throttle = 1350
set rx_min_usec = 885
set rx_max_usec = 2115
set input_filtering_mode = OFF
set blackbox_p_ratio = 32
set blackbox_device = SDCARD
set blackbox_on_motor_test = OFF
set blackbox_record_acc = ON
set min_throttle = 1152
set max_throttle = 2000
set min_command = 1000
set dshot_idle_value = 450
set use_unsynced_pwm = OFF
set motor_pwm_protocol = DSHOT600
set motor_pwm_rate = 480
set motor_pwm_inversion = OFF
set thr_corr_value = 0
set thr_corr_angle = 800
set failsafe_delay = 4
set failsafe_off_delay = 10
set failsafe_throttle = 1000
set failsafe_kill_switch = OFF
set failsafe_throttle_low_delay = 100
set failsafe_procedure = DROP
set align_board_roll = 0
set align_board_pitch = 0
set align_board_yaw = 180
set gimbal_mode = NORMAL
set bat_capacity = 0
set vbat_max_cell_voltage = 43
set vbat_full_cell_voltage = 41
set vbat_min_cell_voltage = 33
set vbat_warning_cell_voltage = 35
set vbat_hysteresis = 1
set current_meter = ADC
set battery_meter = ADC
set vbat_detect_cell_voltage = 30
set use_vbat_alerts = ON
set use_cbat_alerts = OFF
set cbat_alert_percent = 10
set vbat_cutoff_percent = 100
set vbat_scale = 110
set ibata_scale = 400
set ibata_offset = 0
set ibatv_scale = 0
set ibatv_offset = 0
set beeper_inversion = ON
set beeper_od = OFF
set beeper_frequency = 0
set beeper_dshot_beacon_tone = 0
set yaw_motors_reversed = OFF
set 3d_deadband_low = 1406
set 3d_deadband_high = 1514
set 3d_neutral = 1460
set 3d_deadband_throttle = 50
set servo_center_pulse = 1500
set servo_pwm_rate = 50
set servo_lowpass_hz = 0
set tri_unarmed_servo = ON
set channel_forwarding_start = 4
set reboot_character = 82
set serial_update_rate_hz = 100
set accxy_deadband = 40
set accz_deadband = 40
set acc_unarmedcal = ON
set imu_dcm_kp = 2500
set imu_dcm_ki = 0
set small_angle = 25
set auto_disarm_delay = 5
set disarm_kill_switch = ON
set gyro_cal_on_first_arm = OFF
set fixedwing_althold_reversed = OFF
set alt_hold_deadband = 40
set alt_hold_fast_change = ON
set deadband = 0
set yaw_deadband = 5
set yaw_control_reversed = OFF
set pid_process_denom = 4
set tlm_switch = OFF
set tlm_inverted = OFF
set tlm_halfduplex = ON
set frsky_default_lat = 0
set frsky_default_long = 0
set frsky_gps_format = 0
set frsky_unit = IMPERIAL
set frsky_vfas_precision = 0
set hott_alarm_int = 5
set pid_in_tlm = OFF
set ledstrip_visual_beeper = OFF
set sdcard_dma = OFF
set osd_units = METRIC
set osd_rssi_alarm = 20
set osd_cap_alarm = 2200
set osd_alt_alarm = 100
set osd_ah_max_pit = 20
set osd_ah_max_rol = 40
set osd_tim1 = 2560
set osd_tim2 = 2561
set osd_vbat_pos = 2092
set osd_rssi_pos = 2088
set osd_tim_1_pos = 2102
set osd_tim_2_pos = 2081
set osd_flymode_pos = 2381
set osd_throttle_pos = 2273
set osd_vtx_channel_pos = 2425
set osd_crosshairs = 2248
set osd_ah_sbar = 2248
set osd_ah_pos = 2248
set osd_current_pos = 2433
set osd_mah_drawn_pos = 2401
set osd_craft_name_pos = 2410
set osd_gps_speed_pos = 2266
set osd_gps_lon_pos = 2130
set osd_gps_lat_pos = 2113
set osd_gps_sats_pos = 2099
set osd_home_dir_pos = 2350
set osd_home_dist_pos = 2351
set osd_compass_bar_pos = 2314
set osd_altitude_pos = 2295
set osd_pid_roll_pos = 2471
set osd_pid_pitch_pos = 2503
set osd_pid_yaw_pos = 2535
set osd_debug_pos = 2049
set osd_power_pos = 2369
set osd_pidrate_profile_pos = 2393
set osd_warnings_pos = 2377
set osd_avg_cell_voltage_pos = 2124
set osd_pit_ang_pos = 2305
set osd_rol_ang_pos = 2337
set osd_battery_usage_pos = 2440
set osd_disarmed_pos = 2186
set osd_nheading_pos = 2359
set osd_nvario_pos = 2327
set osd_esc_tmp_pos = 2130
set osd_esc_rpm_pos = 2131
set osd_stat_max_spd = ON
set osd_stat_max_dist = OFF
set osd_stat_min_batt = ON
set osd_stat_min_rssi = ON
set osd_stat_max_curr = ON
set osd_stat_used_mah = ON
set osd_stat_max_alt = OFF
set osd_stat_bbox = ON
set osd_stat_endbatt = OFF
set osd_stat_bb_no = ON
set osd_stat_tim_1 = OFF
set osd_stat_tim_2 = ON
set task_statistics = ON
set debug_mode = NONE
set pwr_on_arm_grace = 0
set vtx_halfduplex = ON
set vcd_video_system = 0
set vcd_h_offset = 0
set vcd_v_offset = 0
set max7456_clock = DEFAULT
set displayport_msp_col_adjust = 0
set displayport_msp_row_adjust = 0
set displayport_max7456_col_adjust = 0
set displayport_max7456_row_adjust = 0
set displayport_max7456_inv = OFF
set displayport_max7456_blk = 0
set displayport_max7456_wht = 2
set esc_sensor_halfduplex = OFF
set led_inversion = 0
set dashboard_i2c_bus = 1
set dashboard_i2c_addr = 60
set camera_control_mode = HARDWARE_PWM
set camera_control_ref_voltage = 330
set camera_control_key_delay = 180
set camera_control_internal_resistance = 470
profile 0

set dterm_lowpass_type = BIQUAD
set dterm_lowpass = 100
set dterm_notch_hz = 260
set dterm_notch_cutoff = 160
set vbat_pid_gain = OFF
set pid_at_min_throttle = ON
set anti_gravity_threshold = 350
set anti_gravity_gain = 1000
set setpoint_relax_ratio = 100
set dterm_setpoint_weight = 0
set acc_limit_yaw = 100
set acc_limit = 0
set crash_dthreshold = 50
set crash_gthreshold = 400
set crash_setpoint_threshold = 350
set crash_time = 500
set crash_delay = 0
set crash_recovery_angle = 10
set crash_recovery_rate = 100
set crash_limit_yaw = 200
set crash_recovery = OFF
set iterm_windup = 50
set iterm_limit = 150
set pidsum_limit = 500
set pidsum_limit_yaw = 400
set yaw_lowpass = 0
set p_pitch = 40
set i_pitch = 57
set d_pitch = 20
set p_roll = 40
set i_roll = 57
set d_roll = 20
set p_yaw = 70
set i_yaw = 45
set d_yaw = 20
set p_alt = 50
set i_alt = 0
set d_alt = 0
set p_level = 50
set i_level = 50
set d_level = 75
set p_vel = 55
set i_vel = 55
set d_vel = 75
set level_limit = 55
set horizon_tilt_effect = 75
set horizon_tilt_expert_mode = OFF
rateprofile 0

set rc_rate = 99
set rc_rate_yaw = 100
set rc_expo = 25
set rc_expo_yaw = 25
set thr_mid = 50
set thr_expo = 25
set roll_srate = 67
set pitch_srate = 67
set yaw_srate = 64
set tpa_rate = 10
set tpa_breakpoint = 1650

#2

Double check your Motor screws…
If they are to long they can cause the Motor to get pretty hot.


#3

It looks like you have 20 on the yaw D. I would have it at 0.

And try lowering the D on pitch and roll.

HIGH D MAKES MOTORS HOT ALONG WITH MOTOR SCREWS TOUCHING THE WINDINGS.


#4

I have double checked and the motor screws are not touching the windings.

I have set the yaw D to 0 and halved the D on pitch and roll. I think I can here oscillations when hovering, should I bring down the P and I as well?

The PID values are now a lower than their defaults, is this because of the size of the quad?


#5

Because smaller quads are more agile you might need lower gains. But it really depends on your entire setup

Using high pitch props (or the wrong props) can also strain motors alot more causing them to get got. But on a side note it is normal for these smaller motors to run hotter then larger motors used on fpv.wuads (like 2205 size). But if they burn you when you touch them after a short flight is probably abit too high :hot_pepper: