FlexRC Ascent 3" HD - Caddx Vista

By wrong17 on Jan 02, 2021

11  324  0

This FlexRC Ascent 3" frame has been through many transformations and this might be the final one. I am not saying this is the best version, but this might be the last time I use this frame before it is retired. This frame is simple and durable, but it is not the prettiest of frames. While building this quad, I think I might understand why the guy sold the electronics to me so cheap. I paid $10 for a full GEPRC Stable Pro F7 Dual 20x20 Stack/Combo (Dual Gyro F7 FC, 35A 32bit 4in1, 500mW VTX), Caddx Tarsier with missing lens, 3 GEPRC 1204 5000kv motors, RXSR, and some frame parts. For that price, I guess I cannot really complain about it when the flight stack has some strange issues. It was like musical UARTs, because I must guess and check to see which one will work. If I knew that the UARTs was being problematic I would have spent the time and figured out the problem. But I kept assuming the next one I picked was working. In the end I had to take apart the quad a few times and re-solder a different UART. I was lucky that this was a F7 board that had many free UARTs to choose from.

Betaflight Setup

Once again I started with some of the simlar setting as I would do with a 5" quad and so far it is working well.

In CLI I enabled the BF 4.2 Preset:

HD (smoothed FF for HD cameras, strong low turn rate smoothness, low iterm relax to minimise bounce back)

set iterm_relax_cutoff = 10
set rc_smoothing_auto_smoothness = 20
set ff_interpolate_sp = AVERAGED_3
set ff_smooth_factor = 40
set ff_spike_limit = 55
set ff_boost = 0
set feedforward_transition = 40
set yaw_lowpass_hz = 70
set throttle_boost = 5
set throttle_boost_cutoff = 10
set dyn_lpf_dterm_curve_expo = 7
set gyro_rpm_notch_q = 800

Vbat Compensation

set vbat_sag_compensation = 100
set vbat_pid_gain = off

I also had to enter some filter settings in Betaflight and update the BLHeli32 ESC to 32.7 so it will support Bidirectional DSHOT @ 48Khz.

Test Flight


Part List


Ascent X 3" HD - FPV Racing Drone Frame (6 builds)

Flight Controller

GEPRC Stable Pro F7 Dual 2-6S 20x20 Stack/Combo (Dual Gyro F7 FC / 32bit 35A 4in1 ESC / 25-500mW VTX) (3 builds)


4 x AirBlade Superman AB 1404 Toothpick 3/4 inch Brushless Motors (58 builds)


HQ Prop 3x3x3 PC Durable Tri-Blade 3" Prop 4 Pack (5mm Shaft) - Choose Your Color (14 builds)

FPV Camera

Caddx Vista Digital HD System for DJI HD FPV (98 builds)


iFlight SIGMA 5.8GHz U.FL Antenna - Choose Your Polarization and Color (17 builds)


Team BlackSheep TBS Crossfire Nano RX - Heli-Nation (1484 builds)


Team BlackSheep TBS TANGO 2 V3 PRO RC RADIO (104 builds)


DJI Goggles 2 (7 builds)

HD Camera

GoPro Bones - HERO10 Black (FPV Lightweight Drone Camera) (3 builds)
See Site

Battery Charger

HOTA F6+ 1000W 60A 1-6S Quad Channel AC/DC Smart Charger - Grey

Battery Charger

HOTA D6 PRO Dual Charger 1-6S AC200W/DC650W 15A w/ Wireless Cellphone Charging - Black (14 builds)

Soldering Iron

TS100 Portable Programmable Smart Soldering Iron (264 builds)


Lowepro QuadGuard BP X3 - Drone Backpack for 4 FPV Quad Racing Drones and 15" Laptop w/Exterior Mounts (Black)


iFlight Crystal HD Patch and Stubby 5.8GHz RP-SMA Antenna Set for DJI - LHCP - Carbon
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