Fig. 05 · Racing · Betaflight 2026.6.2

5-inch racing quad

Fly it

Parts: …
Battery: unplugged
Fault: none

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Pick the battery, motors and props. Every number below is recalculated from this craft's own model.

Battery

Motors

Props

Calculated for this build

All-up weight: 443 g
Thrust : weight: 13.8 : 1
Hover throttle: 27%
Max current: 217 A
Hover time: 7.1 min
Hard-flying time: 3.0 min

Checks

Race-ready: 13.8:1 thrust to weight. If the ESC check below speaks up, that is full-throttle headroom: a smoother prop or a bigger ESC fixes it.

No problems found with this combination.

Cost

Category	Parts	Cost
Electrical	9	$279
Mechanical	4	$63
Total (approx.)	13	$342

A working emulation of the Betaflight command line for this craft: real setting names, real limits and real error messages.

Entering CLI Mode, type 'exit' to return, or 'help'

Up and down recall earlier commands.

Configuration snippets

First setup after the build

QUAD X mixer, the board's arrow forward, DShot600 with bidirectional telemetry for the RPM filter, props in, and the two serial ports: the ELRS receiver on UART2 and the VTX's SmartAudio on UART1.

# Betaflight 2026.6.2 on a 20 x 20 F7 stack: ELRS on UART2, SmartAudio VTX on UART1
mixer QUADX
set align_board_yaw = 0            # arrow to the nose; 180 if it points back
set motor_pwm_protocol = DSHOT600
set dshot_bidir = ON               # rpm telemetry for the RPM filter
set motor_poles = 14               # 14 magnets in a 2207 bell
set yaw_motors_reversed = OFF      # props in (ON = props out)
serial UART2 64 115200 57600 0 115200    # 64 = serial RX (ELRS)
set serialrx_provider = CRSF
serial UART1 2048 115200 57600 0 115200  # 2048 = SmartAudio (VTX)
save

Race switches after the build

Arm on AUX1, angle on AUX2, VTX pit mode on AUX3, and launch control and the lost-quad beeper on the two ends of AUX4. aux takes Betaflight's numeric mode ids: 0 arm, 1 angle, 39 pit mode, 49 launch control, 13 beeper.

# aux <slot> <mode id> <AUX n - 1> <from us> <to us> <logic> <linked>
aux 0 0 0 1700 2100 0 0      # ARM on AUX1 high
aux 1 1 1 1300 2100 0 0      # ANGLE on AUX2 mid + high (low = acro)
aux 2 39 2 1700 2100 0 0     # VTX PIT MODE on AUX3 high
aux 3 49 3 1700 2100 0 0     # LAUNCH CONTROL on AUX4 high
aux 4 13 3 900 1300 0 0      # BEEPER on AUX4 low: find it after a crash
save

Raceband, your channel, 25 mW after the build

The VTX table tells Betaflight which bands and power levels the transmitter has (channels first, or the band lines fail). Band 5 is Raceband; channel 4 is 5769 MHz. Power index 1 is the lowest real level, 25 mW, the power for racing next to other pilots. Low power while disarmed and a pit-mode frequency off the race band keep you from wiping out someone's video at the pits.

# SmartAudio 2.1 VTX: channels before bands, then the power table
vtxtable bands 5
vtxtable channels 8
vtxtable band 1 BOSCAM_A A FACTORY 5865 5845 5825 5805 5785 5765 5745 5725
vtxtable band 2 BOSCAM_B B FACTORY 5733 5752 5771 5790 5809 5828 5847 5866
vtxtable band 3 BOSCAM_E E FACTORY 5705 5685 5665 5645 5885 5905 5925 5945
vtxtable band 4 FATSHARK F FACTORY 5740 5760 5780 5800 5820 5840 5860 5880
vtxtable band 5 RACEBAND R FACTORY 5658 5695 5732 5769 5806 5843 5880 5917
vtxtable powerlevels 3
vtxtable powervalues 14 20 26
vtxtable powerlabels 25 100 400
set vtx_band = 5                   # Raceband
set vtx_channel = 4                # R4, 5769 MHz: the channel race control gave you
set vtx_power = 1                  # 25 mW, the event power
set vtx_low_power_disarm = ON      # lowest power until armed
set vtx_pit_mode_freq = 5584       # PIT MODE moves off the race band
save

Race colour LEDs after the build

The layout is one led line per LED: grid position, no directions, function C (solid colour) and colour 6 (GREEN); the Configurator’s LED Strip tab writes the same lines. This lab’s CLI doesn’t take led lines, so they are shown as comments. The two set lines pick the RACE profile, which lights the whole strip in ledstrip_race_color: a colour name, not a number.

# 8 WS2812B LEDs, 4 on each rear arm, all one race colour. The LED Strip tab writes the layout,
# one line per LED: led <n> <x>,<y>:<directions>:<functions>:<colour> (C = solid colour, 6 = GREEN)
#   led 0 0,0::C:6    led 1 1,0::C:6    led 2 2,0::C:6    led 3 3,0::C:6
#   led 4 12,0::C:6   led 5 13,0::C:6   led 6 14,0::C:6   led 7 15,0::C:6
set ledstrip_profile = RACE
set ledstrip_race_color = GREEN    # a name, not a number; BLACK = follow the VTX channel
save

Failsafe: drop after the build

If the radio link is lost for 1.5 s, stop the motors. On a race track inside nets, dropping is safer than any attempt to fly home, and a race quad has no GPS to fly home with.

# Lost link: hold for 1.5 s (stage 1), then stop the motors (stage 2) inside the netted track
set failsafe_delay = 15            # tenths of a second
set failsafe_procedure = DROP
save

Angle mode for learning the track for Angle

Self-levelling with the tilt capped at 45°: let go of the stick and it levels out. Good for learning the gate order; too slow to race, because the cap also limits how hard it can pitch forward.

# Angle mode for learning the track: self-levelling, tilt capped
aux 1 1 1 1300 2100 0 0      # ANGLE on AUX2 mid + high
set angle_limit = 45         # max tilt, degrees (10-80, default 60)
set angle_p_gain = 50        # how hard it levels (0-200, default 50)
save

Race rates for Acro

Acro is what the quad flies with no self-level mode on. With ACTUAL rates the centre is soft (70°/s) for small line corrections and full stick turns at 670°/s for flicks round a gate; yaw tops out at 450°/s.

# Race rates (ACTUAL): soft centre for small corrections, fast at full stick
set rates_type = ACTUAL
set roll_rc_rate = 7         # centre: 70 deg/s per full stick
set roll_srate = 67          # full stick: 670 deg/s
set roll_expo = 40
set pitch_rc_rate = 7
set pitch_srate = 67
set pitch_expo = 40
set yaw_srate = 45           # yaw: 450 deg/s
save

Race timer and launch control for Race (angle)

The OSD timer counts in hundredths from the last arm, so a pilot sees the heat time in the goggles; the lap times themselves come from the race timer listening to each VTX. Launch control holds the quad on the grid until the throttle passes 20 %, for a clean start on the tone.

# Race timer on the OSD: time since the last arm, in hundredths
set osd_tim1 = 18            # source 2 (last armed) + precision 1 (hundredths) << 4
set osd_tim_1_pos = 2103     # 2048 (OSD profile 1) + column 23 + row 1 x 32
# Launch control: sit armed on the grid, nose held, until the throttle passes 20 %
set launch_control_mode = PITCHONLY
set launch_trigger_throttle_percent = 20
set launch_angle_limit = 0   # 0 = no tilt stop (needs the accelerometer)
set launch_control_gain = 40
save

Racing in acro for Race (acro)

Angle off, air mode on so the quad still steers at zero throttle over the top of a dive, launch control for the start and the race timer on the OSD.

# Racing in acro: ANGLE off (AUX2 low), air mode on, launch control on AUX4 for the start
feature AIRMODE              # on by default; keeps full control at zero throttle
aux 3 49 3 1700 2100 0 0     # LAUNCH CONTROL on AUX4 high
set osd_tim1 = 18
set osd_tim_1_pos = 2103
save

Meet the racing quad

A race quad is a 5-inch FPV quad stripped down to do one thing: get round a gate track faster than everyone else in the heat. It weighs about 440 g with a 4S 1300 mAh pack and has a thrust-to-weight ratio near 14:1, so it spends most of a lap pitched hard forward at full throttle. The frame is a stretched X, longer than it is wide, so the rear props bite clean air at speed. The pilot flies in acro from analog goggles, because analog video has the lowest delay and every pilot shares Raceband. The VTX runs at 25 mW on the channel race control hands out, so four to eight quads can fly together. LED strips in the pilot's colour let spotters and timers tell the quads apart. Pick the parts here and watch the numbers, build it, run the safety tests, then race the club track.

Practice task

Learn the club track in race mode (angle) until you clear all six gates cleanly, then switch to acro race and chase three laps in a row under par, the way a MultiGP qualifier counts them. On a real build: put a smoke stopper on the first plug, check motor direction with the props off, test the receiver and the failsafe (props off, radio off: the motors must stop), and set your VTX to your assigned channel at 25 mW before you plug in at the pits. Land at about 3.5 V per cell; a race pack lasts two to three minutes at race pace.

Build a gate racer, set its channel, then race the club track

Category

Parts

Cost

Electrical

$279

Mechanical

$63

Total (approx.)

$342

# Betaflight 2026.6.2 on a 20 x 20 F7 stack: ELRS on UART2, SmartAudio VTX on UART1 mixer QUADX set align_board_yaw = 0 # arrow to the nose; 180 if it points back set motor_pwm_protocol = DSHOT600 set dshot_bidir = ON # rpm telemetry for the RPM filter set motor_poles = 14 # 14 magnets in a 2207 bell set yaw_motors_reversed = OFF # props in (ON = props out) serial UART2 64 115200 57600 0 115200 # 64 = serial RX (ELRS) set serialrx_provider = CRSF serial UART1 2048 115200 57600 0 115200 # 2048 = SmartAudio (VTX) save

# aux <slot> <mode id> <AUX n - 1> <from us> <to us> <logic> <linked> aux 0 0 0 1700 2100 0 0 # ARM on AUX1 high aux 1 1 1 1300 2100 0 0 # ANGLE on AUX2 mid + high (low = acro) aux 2 39 2 1700 2100 0 0 # VTX PIT MODE on AUX3 high aux 3 49 3 1700 2100 0 0 # LAUNCH CONTROL on AUX4 high aux 4 13 3 900 1300 0 0 # BEEPER on AUX4 low: find it after a crash save

# SmartAudio 2.1 VTX: channels before bands, then the power table vtxtable bands 5 vtxtable channels 8 vtxtable band 1 BOSCAM_A A FACTORY 5865 5845 5825 5805 5785 5765 5745 5725 vtxtable band 2 BOSCAM_B B FACTORY 5733 5752 5771 5790 5809 5828 5847 5866 vtxtable band 3 BOSCAM_E E FACTORY 5705 5685 5665 5645 5885 5905 5925 5945 vtxtable band 4 FATSHARK F FACTORY 5740 5760 5780 5800 5820 5840 5860 5880 vtxtable band 5 RACEBAND R FACTORY 5658 5695 5732 5769 5806 5843 5880 5917 vtxtable powerlevels 3 vtxtable powervalues 14 20 26 vtxtable powerlabels 25 100 400 set vtx_band = 5 # Raceband set vtx_channel = 4 # R4, 5769 MHz: the channel race control gave you set vtx_power = 1 # 25 mW, the event power set vtx_low_power_disarm = ON # lowest power until armed set vtx_pit_mode_freq = 5584 # PIT MODE moves off the race band save

# 8 WS2812B LEDs, 4 on each rear arm, all one race colour. The LED Strip tab writes the layout, # one line per LED: led <n> <x>,<y>:<directions>:<functions>:<colour> (C = solid colour, 6 = GREEN) # led 0 0,0::C:6 led 1 1,0::C:6 led 2 2,0::C:6 led 3 3,0::C:6 # led 4 12,0::C:6 led 5 13,0::C:6 led 6 14,0::C:6 led 7 15,0::C:6 set ledstrip_profile = RACE set ledstrip_race_color = GREEN # a name, not a number; BLACK = follow the VTX channel save

# Angle mode for learning the track: self-levelling, tilt capped aux 1 1 1 1300 2100 0 0 # ANGLE on AUX2 mid + high set angle_limit = 45 # max tilt, degrees (10-80, default 60) set angle_p_gain = 50 # how hard it levels (0-200, default 50) save

# Race rates (ACTUAL): soft centre for small corrections, fast at full stick set rates_type = ACTUAL set roll_rc_rate = 7 # centre: 70 deg/s per full stick set roll_srate = 67 # full stick: 670 deg/s set roll_expo = 40 set pitch_rc_rate = 7 set pitch_srate = 67 set pitch_expo = 40 set yaw_srate = 45 # yaw: 450 deg/s save

# Race timer on the OSD: time since the last arm, in hundredths set osd_tim1 = 18 # source 2 (last armed) + precision 1 (hundredths) << 4 set osd_tim_1_pos = 2103 # 2048 (OSD profile 1) + column 23 + row 1 x 32 # Launch control: sit armed on the grid, nose held, until the throttle passes 20 % set launch_control_mode = PITCHONLY set launch_trigger_throttle_percent = 20 set launch_angle_limit = 0 # 0 = no tilt stop (needs the accelerometer) set launch_control_gain = 40 save

# Racing in acro: ANGLE off (AUX2 low), air mode on, launch control on AUX4 for the start feature AIRMODE # on by default; keeps full control at zero throttle aux 3 49 3 1700 2100 0 0 # LAUNCH CONTROL on AUX4 high set osd_tim1 = 18 set osd_tim_1_pos = 2103 save

Meet the racing quad

Practice task

Build a gate racer, set its channel, then race the club track

5-inch racing quad

Design it

Calculated for this build

Checks

Cost

Build it

Try a real mistake

Selected part

Parts in the box

Wiring

Safety tests

Smoke stopper test

Motor direction check (props off)

Accelerometer calibration

Receiver test

Failsafe test (props off, radio off)

Betaflight CLI console

Configuration snippets

First setup after the build

Race switches after the build

Raceband, your channel, 25 mW after the build

Race colour LEDs after the build

Failsafe: drop after the build

Angle mode for learning the track for Angle

Race rates for Acro

Race timer and launch control for Race (angle)

Racing in acro for Race (acro)

Check yourself · Mount the four race motors

Check yourself · Solder the XT60 lead and the capacitor

Check yourself · Fit the race VTX on top of the stack

Check yourself

Meet the racing quad

Practice task

5-inch racing quad

Design it

Calculated for this build

Checks

Cost

Build it

Try a real mistake

Selected part

Parts in the box

Wiring

Safety tests

Smoke stopper test

Motor direction check (props off)

Accelerometer calibration

Receiver test

Failsafe test (props off, radio off)

Betaflight CLI console

Configuration snippets

First setup after the build

Race switches after the build

Raceband, your channel, 25 mW after the build

Race colour LEDs after the build

Failsafe: drop after the build

Angle mode for learning the track for Angle

Race rates for Acro

Race timer and launch control for Race (angle)

Racing in acro for Race (acro)

Check yourself · Mount the four race motors

Check yourself · Solder the XT60 lead and the capacitor

Check yourself · Fit the race VTX on top of the stack

Check yourself

Meet the racing quad

Practice task