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