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lorentz · 22-Feb-2017, 03:04 PM

Hello, i've a problem with my first brushless "serious" built .
I'm posting here because i think it's the appropriate section.(sorry for my bad English)

I've a twitching/stuttering motor problem.

On the bench the motors are running ok but when armed and just hovering there are something like very fast bursts of "cuts of power" in a fraction of second(making a sketchy braking/stuttering sound).It seems happening when pushing up throttle even gently.
Soldering and connections are ok since on bench i've no problem in all throttle ranges and touching the wires when motors running didn't change the sound or rpms feeling.
The motors get warm in a minute with props on too.
Props used: dalprop 5040 tri (very flexy) and gemfan 5040 hybrid 2blades(stiffer)
My setup:
Gep vx 5 frame,racerstar rf 2205-2300kv,racerstar ms35a(flashed 16.6 ah-20 firmware), xracer f303v3.1(latest fw),4s lipo.
here's my dump:

Code:
# Betaflight / X_RACERSPI 3.1.5 Feb  7 2017 / 22:34:57 (4646f9d)
 name Gep Ge VX 5
 resource BEEPER 1 C15
 resource MOTOR 1 A06
 resource MOTOR 2 A07
 resource MOTOR 3 A11
 resource MOTOR 4 A12
 resource MOTOR 5 B08
 resource MOTOR 6 B09
 resource MOTOR 7 A02
 resource MOTOR 8 A03
 resource MOTOR 9 A08
 resource MOTOR 10 NONE
 resource MOTOR 11 NONE
 resource MOTOR 12 NONE
 resource SERVO 1 NONE
 resource SERVO 2 NONE
 resource SERVO 3 NONE
 resource SERVO 4 NONE
 resource SERVO 5 NONE
 resource SERVO 6 NONE
 resource SERVO 7 NONE
 resource SERVO 8 NONE
 resource PPM 1 A00
 resource PWM 1 A00
 resource PWM 2 A01
 resource PWM 3 B11
 resource PWM 4 B10
 resource PWM 5 B00
 resource PWM 6 B01
 resource PWM 7 NONE
 resource PWM 8 NONE
 resource LED_STRIP 1 A08
 mixer QUADX
 
 mmix reset
 
 servo 0 1000 2000 1500 90 90 100 -1
 servo 1 1000 2000 1500 90 90 100 -1
 servo 2 1000 2000 1500 90 90 100 -1
 servo 3 1000 2000 1500 90 90 100 -1
 servo 4 1000 2000 1500 90 90 100 -1
 servo 5 1000 2000 1500 90 90 100 -1
 servo 6 1000 2000 1500 90 90 100 -1
 servo 7 1000 2000 1500 90 90 100 -1
 smix reset
 
 
 feature -RX_PPM
 feature -VBAT
 feature -INFLIGHT_ACC_CAL
 feature -RX_SERIAL
 feature -MOTOR_STOP
 feature -SERVO_TILT
 feature -SOFTSERIAL
 feature -GPS
 feature -FAILSAFE
 feature -SONAR
 feature -TELEMETRY
 feature -CURRENT_METER
 feature -3D
 feature -RX_PARALLEL_PWM
 feature -RX_MSP
 feature -RSSI_ADC
 feature -LED_STRIP
 feature -DISPLAY
 feature -OSD
 feature -BLACKBOX
 feature -CHANNEL_FORWARDING
 feature -TRANSPONDER
 feature -AIRMODE
 feature -SDCARD
 feature -VTX
 feature -RX_SPI
 feature -SOFTSPI
 feature -ESC_SENSOR
 feature VBAT
 feature RX_SERIAL
 feature MOTOR_STOP
 feature FAILSAFE
 feature LED_STRIP
 feature BLACKBOX
 beeper GYRO_CALIBRATED
 beeper RX_LOST
 beeper RX_LOST_LANDING
 beeper DISARMING
 beeper ARMING
 beeper ARMING_GPS_FIX
 beeper BAT_CRIT_LOW
 beeper BAT_LOW
 beeper GPS_STATUS
 beeper RX_SET
 beeper ACC_CALIBRATION
 beeper ACC_CALIBRATION_FAIL
 beeper READY_BEEP
 beeper MULTI_BEEPS
 beeper DISARM_REPEAT
 beeper ARMED
 beeper SYSTEM_INIT
 beeper ON_USB
 map TAER1234
 serial 0 1 115200 57600 0 115200
 serial 1 0 115200 57600 0 115200
 serial 2 64 115200 57600 0 115200
 led 0 15,15::CTI:2
 led 1 15,14::CTI:2
 led 2 15,13::CTI:2
 led 3 15,1::CTI:2
 led 4 15,0::CTI:2
 led 5 0,15::CTI:2
 led 6 0,14::CTI:2
 led 7 0,13::CTI:2
 led 8 0,1::CTI:2
 led 9 0,0::CTI:2
 led 10 0,0::C:0
 led 11 0,0::C:0
 led 12 0,0::C:0
 led 13 0,0::C:0
 led 14 0,0::C:0
 led 15 0,0::C:0
 led 16 0,0::C:0
 led 17 0,0::C:0
 led 18 0,0::C:0
 led 19 0,0::C:0
 led 20 0,0::C:0
 led 21 0,0::C:0
 led 22 0,0::C:0
 led 23 0,0::C:0
 led 24 0,0::C:0
 led 25 0,0::C:0
 led 26 0,0::C:0
 led 27 0,0::C:0
 led 28 0,0::C:0
 led 29 0,0::C:0
 led 30 0,0::C:0
 led 31 0,0::C:0
 color 0 0,0,0
 color 1 0,255,255
 color 2 0,0,255
 color 3 30,0,255
 color 4 60,0,255
 color 5 90,0,255
 color 6 120,0,255
 color 7 150,0,255
 color 8 180,0,255
 color 9 210,0,255
 color 10 240,0,255
 color 11 270,0,255
 color 12 300,0,255
 color 13 330,0,255
 color 14 0,0,0
 color 15 0,0,0
 mode_color 0 0 1
 mode_color 0 1 11
 mode_color 0 2 2
 mode_color 0 3 13
 mode_color 0 4 10
 mode_color 0 5 3
 mode_color 1 0 5
 mode_color 1 1 11
 mode_color 1 2 3
 mode_color 1 3 13
 mode_color 1 4 10
 mode_color 1 5 3
 mode_color 2 0 10
 mode_color 2 1 11
 mode_color 2 2 4
 mode_color 2 3 13
 mode_color 2 4 10
 mode_color 2 5 3
 mode_color 3 0 8
 mode_color 3 1 11
 mode_color 3 2 4
 mode_color 3 3 13
 mode_color 3 4 10
 mode_color 3 5 3
 mode_color 4 0 7
 mode_color 4 1 11
 mode_color 4 2 3
 mode_color 4 3 13
 mode_color 4 4 10
 mode_color 4 5 3
 mode_color 5 0 9
 mode_color 5 1 11
 mode_color 5 2 2
 mode_color 5 3 13
 mode_color 5 4 10
 mode_color 5 5 3
 mode_color 6 0 6
 mode_color 6 1 10
 mode_color 6 2 1
 mode_color 6 3 0
 mode_color 6 4 0
 mode_color 6 5 2
 mode_color 6 6 3
 mode_color 6 7 6
 mode_color 6 8 0
 mode_color 6 9 0
 mode_color 6 10 0
 mode_color 7 0 3
 aux 0 0 0 1550 2100
 aux 1 2 1 1700 2100
 aux 2 0 0 900 900
 aux 3 0 0 900 900
 aux 4 0 0 900 900
 aux 5 0 0 900 900
 aux 6 0 0 900 900
 aux 7 0 0 900 900
 aux 8 0 0 900 900
 aux 9 0 0 900 900
 aux 10 0 0 900 900
 aux 11 0 0 900 900
 aux 12 0 0 900 900
 aux 13 0 0 900 900
 aux 14 0 0 900 900
 aux 15 0 0 900 900
 aux 16 0 0 900 900
 aux 17 0 0 900 900
 aux 18 0 0 900 900
 aux 19 0 0 900 900
 adjrange 0 0 0 900 900 0 0
 adjrange 1 0 0 900 900 0 0
 adjrange 2 0 0 900 900 0 0
 adjrange 3 0 0 900 900 0 0
 adjrange 4 0 0 900 900 0 0
 adjrange 5 0 0 900 900 0 0
 adjrange 6 0 0 900 900 0 0
 adjrange 7 0 0 900 900 0 0
 adjrange 8 0 0 900 900 0 0
 adjrange 9 0 0 900 900 0 0
 adjrange 10 0 0 900 900 0 0
 adjrange 11 0 0 900 900 0 0
 adjrange 12 0 0 900 900 0 0
 adjrange 13 0 0 900 900 0 0
 adjrange 14 0 0 900 900 0 0
 rxrange 0 1067 1928
 rxrange 1 1067 1928
 rxrange 2 1067 1928
 rxrange 3 1068 1923
 rxfail 0 a
 rxfail 1 a
 rxfail 2 a
 rxfail 3 a
 rxfail 4 h
 rxfail 5 h
 rxfail 6 h
 rxfail 7 h
 rxfail 8 h
 rxfail 9 h
 rxfail 10 h
 rxfail 11 h
 rxfail 12 h
 rxfail 13 h
 rxfail 14 h
 rxfail 15 h
 rxfail 16 h
 rxfail 17 h
 set task_statistics = ON
 set mid_rc = 1500
 set min_check = 1100
 set max_check = 1900
 set rssi_channel = 0
 set rssi_scale = 30
 set rc_interp = AUTO
 set rc_interp_ch = RP
 set rc_interp_int = 19
 set rssi_ppm_invert = OFF
 set input_filtering_mode = OFF
 set fpv_mix_degrees = 0
 set max_aux_channels = 6
 set debug_mode = NONE
 set min_throttle = 1050
 set max_throttle = 2000
 set min_command = 1000
 set digital_idle_percent =  4.500
 set 3d_deadband_low = 1406
 set 3d_deadband_high = 1514
 set 3d_neutral = 1460
 set 3d_deadband_throttle = 50
 set use_unsynced_pwm = ON
 set motor_pwm_protocol = MULTISHOT
 set motor_pwm_rate = 32000
 set disarm_kill_switch = ON
 set gyro_cal_on_first_arm = OFF
 set auto_disarm_delay = 5
 set small_angle = 25
 set fixedwing_althold_dir = 1
 set reboot_character = 82
 set serial_update_rate_hz = 100
 set gps_provider = NMEA
 set gps_sbas_mode = AUTO
 set gps_auto_config = ON
 set gps_auto_baud = OFF
 set gps_wp_radius = 200
 set nav_controls_heading = ON
 set nav_speed_min = 100
 set nav_speed_max = 300
 set nav_slew_rate = 30
 set beeper_inversion = ON
 set beeper_od = OFF
 set serialrx_provider = SPEK2048
 set sbus_inversion = ON
 set spektrum_sat_bind = 0
 set spektrum_sat_bind_autorst = 1
 set tlm_switch = OFF
 set tlm_inversion = ON
 set sport_halfduplex = ON
 set frsky_default_lat =  0.000
 set frsky_default_long =  0.000
 set frsky_gps_format = 0
 set frsky_unit = IMPERIAL
 set frsky_vfas_precision = 0
 set frsky_vfas_cell_voltage = OFF
 set hott_alarm_int = 5
 set pid_in_tlm = OFF
 set bat_capacity = 0
 set vbat_scale = 110
 set vbat_max_cell_voltage = 43
 set vbat_min_cell_voltage = 33
 set vbat_warning_cell_voltage = 35
 set vbat_hysteresis = 1
 set ibat_scale = 400
 set ibat_offset = 0
 set mwii_ibat_output = OFF
 set current_meter_type = ADC
 set battery_meter_type = ADC
 set bat_detect_thresh = 55
 set use_vbat_alerts = ON
 set use_cbat_alerts = OFF
 set cbat_alert_percent = 10
 set align_gyro = DEFAULT
 set align_acc = DEFAULT
 set align_mag = DEFAULT
 set align_board_roll = 0
 set align_board_pitch = 0
 set align_board_yaw = 0
 set gyro_lpf = OFF
 set gyro_sync_denom = 1
 set gyro_isr_update = OFF
 set gyro_use_32khz = OFF
 set gyro_lowpass_type = PT1
 set gyro_lowpass = 90
 set gyro_notch1_hz = 400
 set gyro_notch1_cut = 300
 set gyro_notch2_hz = 200
 set gyro_notch2_cut = 100
 set moron_threshold = 48
 set imu_dcm_kp = 2500
 set imu_dcm_ki = 0
 set alt_hold_deadband = 40
 set alt_hold_fast_change = ON
 set deadband = 0
 set yaw_deadband = 0
 set thr_corr_value = 0
 set thr_corr_angle = 800
 set yaw_control_direction = 1
 set yaw_motor_direction = 1
 set servo_center_pulse = 1500
 set tri_unarmed_servo = ON
 set servo_lowpass_hz = 400
 set servo_lowpass = OFF
 set servo_pwm_rate = 50
 set gimbal_mode = NORMAL
 set channel_forwarding_start = 4
 set airmode_start_throttle = 1350
 set failsafe_delay = 10
 set failsafe_off_delay = 10
 set failsafe_throttle = 1000
 set failsafe_kill_switch = ON
 set failsafe_throttle_low_delay = 100
 set failsafe_procedure = DROP
 set rx_min_usec = 885
 set rx_max_usec = 2115
 set acc_hardware = AUTO
 set acc_lpf_hz = 10
 set accxy_deadband = 40
 set accz_deadband = 40
 set acc_unarmedcal = ON
 set acc_trim_pitch = 0
 set acc_trim_roll = 0
 set pid_process_denom = 2
 set blackbox_rate_num = 1
 set blackbox_rate_denom = 4
 set blackbox_device = SPIFLASH
 set blackbox_on_motor_test = OFF
 set ledstrip_visual_beeper = OFF
 set displayport_msp_col_adjust = 0
 set displayport_msp_row_adjust = 0
 profile 0
 
 set gps_pos_p = 15
 set gps_pos_i = 0
 set gps_pos_d = 0
 set gps_posr_p = 34
 set gps_posr_i = 14
 set gps_posr_d = 53
 set gps_nav_p = 25
 set gps_nav_i = 33
 set gps_nav_d = 83
 set yaw_p_limit = 500
 set pidsum_limit =  0.500
 set d_lowpass_type = BIQUAD
 set d_lowpass = 100
 set d_notch_hz = 260
 set d_notch_cut = 160
 set vbat_pid_gain = OFF
 set pid_at_min_throttle = ON
 set anti_gravity_thresh = 350
 set anti_gravity_gain =  1.000
 set setpoint_relax_ratio = 25
 set d_setpoint_weight = 190
 set yaw_accel_limit =  10.000
 set accel_limit =  0.000
 set iterm_windup = 50
 set yaw_lowpass = 0
 set p_pitch = 58
 set i_pitch = 50
 set d_pitch = 19
 set p_roll = 44
 set i_roll = 40
 set d_roll = 17
 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 = 100
 set p_vel = 55
 set i_vel = 55
 set d_vel = 75
 set level_sensitivity = 55
 set level_limit = 55
 rateprofile 0
 rateprofile 0
 
 set rc_rate = 100
 set rc_rate_yaw = 100
 set rc_expo = 0
 set rc_yaw_expo = 0
 set thr_mid = 50
 set thr_expo = 0
 set roll_srate = 70
 set pitch_srate = 70
 set yaw_srate = 70
 set tpa_rate = 10
 set tpa_breakpoint = 1650
 
 #

And Blackbox log
https://www.dropbox.com/s/4a9ycmmeuir1n4...7.BFL?dl=0
blheli screenshot:
[url=https://www.dropbox.com/s/4a9ycmmeuir1n48/BLACKBOX_LOG_Gep_Ge%20VX%205_20170222_135657.BFL?dl=0][/url]
[Image: UfNv02Hl.png]

Please someone help me Cry

before i dismantle everything and rebuilt all from zero.
Tia
Lorenzo

fftunes · (This post was last modified: 22-Feb-2017, 04:13 PM by fftunes.)

What size is the quad, and do you have the fc softmounted (i think you said you added o-rings, but it might be not that trivial - if screws are still directly touching the fc, yaw noise/vibrations will still be transferred from frame to fc).

To test first wether it's a yaw problem, you could lower or even zero yaw P.
If it goes away then, you would have to improve the softmounting (larger holes in fc, or smaller screws, and possibly bevel the fc holes so the o-rings automatically center the screws.

Does the fc have onboard flash or sd-card slot? A log could help in case it's something else... Also, did you try to lower P on pitch or roll, just to test?

lorentz · (This post was last modified: 22-Feb-2017, 05:33 PM by lorentz.)

Hi fftunes,yes i have a 16mb flash onboard and blackbox log and cli dump are attached.
Frame is: http://geprc.com/products/multirotors/gep-vx5/

oyvinla · 22-Feb-2017, 05:58 PM

It looks from the CLI dump that you are running 32k unsynced multishot, am I right? If so, have you tried reducing it to 16k, 8k or same as the pid loop? I don't know if those escs can handle 32k?

lorentz · (This post was last modified: 22-Feb-2017, 06:17 PM by lorentz.)

Yes i'm running 32khz, the escs are almost a fresh release http://www.racerstar.com/Racerstar-MS35A-ESC-p-43.html they can run dshot...
seems they are EFM8BB21 ztw polaris rebranded escs.

oyvinla · 22-Feb-2017, 06:25 PM

I would try to reduce the update frequency or switch to dshot600. It could be that you'll need to remove a capacitor on the escs. if so, try dshot300 instead. Like I said, I don't know how your escs are, but I know that some runs fine on 32k, some don't

RENOV8R · 22-Feb-2017, 06:39 PM

If your ESCs are DShot capable, why don't you try it. And as said above, try dropping to 8k/8k. I'm using a Brain RE1 with DYS SXD 30 amp ESCs with DShot 600 and I've tried every combo from 32k/32k down to 8k/4k. It didn't like 32k/32k but everything else ran great. In fact I couldn't even tell the difference. But that may just because I still suck as a pilot hahaha

fftunes · (This post was last modified: 22-Feb-2017, 07:03 PM by fftunes.)

Sorry didn't see log link before, will check a bit later on pc.

I wouldn't recommend dshot now though as not to complicate things, as your quad basically roughly works for now, but yeah as others mentioned maybe lower esc freq. to 8k just to make sure escs are not the issue.

But another question, do you have a capacitor on pdb or escs?

Hm on the other hand, if no caps, and electrical noise is the issue, then dshot might help the escs at least...

lorentz · 22-Feb-2017, 07:05 PM

Thanks to all.
Now lowering 5 points of D on roll&pitch seem getting better but i still have some twitchings randomly.(same serie of two"crak-crick" sounds)
Tonight i'll try reducing khzs and redo the Fc insulation with softer oring from 1/8 rc buggy shocks,maybe it will works..
Dshot is still far from my soldering/reworking skills,so i'll try to figure it out with oldschool Multishot protocol for now.

fftunes · (This post was last modified: 22-Feb-2017, 08:48 PM by fftunes.)

1st thing i notice in the log: your rc command looks bad. Means you have either misconfigured your tx (sending too long pulses) or misconfigured rc-smoothing in fc. What tx/rx are you using? Or did you disable rc-smoothing completely? Either way your tx is sending in 21ms intervals, which actually look unsmoothed (big steps) which in turn causes big D-term spikes.

A quick dirty fix would be to set rc-smoothing to manual and interval to 21ms. But that's suboptimal.

2nd thing is, yaw gyro looks noisy. You could try to lower yaw P if it doesn't hurt control, but it probably does; you could enable yaw lowcut filter and set it to 60-70hz, but it probably doesn't help much; means you have to improve the soft-mounting i think...

Unless it is electrical noise that's messing with the gyro - not sure you mentioned wether you have caps installed on pdb or escs?

lorentz · 23-Feb-2017, 03:22 AM

I am using a spektrum dx6i with diversity dsmx sat. With defualt settings the values are approx 1140-1840ish so i increased end points closer to correct value and then rcrange cli command to get 1000-2000.
Never modified rc smoothing since in receiver tab i have no visible jitter.

fftunes · (This post was last modified: 23-Feb-2017, 05:52 PM by fftunes.)

With dsmx sat, shouldn't you be able to set it to 11ms in the dx6i? Under the bind-options... I'll check in the evening when i get home.

If not, you could try to set smoothing in betaflight to "manual" and smoothing interval to 22ms.

What version of betaflight are you using?

EDIT: My mistake, checked my old dx6i... not sure if dsm2 modulation would be 11ms, and dsmx receivers should be backwards compatible. Maybe someone else knows. Anyway, there's still the option of manual 22ms smoothing in betaflight.

Also you wrote "latest firmware" on fc, i guess that means betaflight, not cleanflight, and latest would be 3.1.5.
That means roll and pitch should be smoothed by default, but not throttle and yaw.
To enable full smoothing on all channels, in CLI type "set rc_interp_ch = RPYT" and "save".

BTW rc smoothing is not about jitter, it's there for eliminating the steps in rc channels (see rc commands in your log, they look like stairs) which produce huge d-term spikes.

fftunes · 23-Feb-2017, 08:53 PM

edited

lorentz · (This post was last modified: 24-Feb-2017, 04:35 AM by lorentz.)

Thanks for the support.My dx6i is post 2015 euro version so only dsmx 11ms protocol and no more selectable power output. Maybe corrupted binding? Where i can find the option of manual smoothing 22ms (or11ms?) on bf 3.1.5?
Ps:i am getting bored of "iPhone" philosophy of Spektrums. Dsmx,3.3v only sats ecc

lorentz · (This post was last modified: 24-Feb-2017, 05:05 AM by lorentz.)

I found rc smoothing. I was looking in cli commands instead of receiver tab...

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