acroFPV

Advanced tuning

Flight feel slider reference.

The Feel panel turns stick input into target rotation, controller response, motor lag, craft motion, and FPV camera perception. This reference explains what each slider changes and what to adjust when the sim feels too sharp, too heavy, too floaty, or too slow.

Signal path

1. Stick input

Controller calibration maps your radio or gamepad channels into throttle, roll, pitch, and yaw values from -1 to 1.

2. ACTUAL rates

Roll, pitch, and yaw stick positions become requested angular rates in deg/s using center sensitivity, expo, and max rate.

3. Rate controller

P gain, damping, feed forward, and motor response decide how quickly the simulated craft chases the requested rate.

4. Physics and camera

Mass, thrust, inertia, drag, gravity, wind, ground effect, camera tilt, and FOV determine how the motion feels through the FPV view.

Default reference tune

The current acroFPV default tune matches the 5 inch GoPro Freestyle preset: 840 g, 6.7x thrust-to-weight, 35 deg camera angle, 80 deg FOV, and ACTUAL rates of 70 center / 670 max deg/s with 20% expo on roll, pitch, and yaw.

Use the ranges below as simulator tuning ranges. They are not a promise that every extreme value will feel realistic; the edges are there so pilots can explore.

Betaflight ACTUAL rates

These sliders shape the requested rotation before the simulated controller responds. The roll, pitch, and yaw versions behave the same; they are separated so you can make yaw slower, pitch softer, or roll faster without changing the other axes.

expo = expoPercent / 100
expoCurve = abs(stick) * (stick^5 * expo + stick * (1 - expo))
rateDps = stick * centerDps + (maxDps - centerDps) * expoCurve
targetRate = clamp(rateDps, -1998, 1998) deg/s
Slider Default Range Raise it Lower it
Roll center, pitch center, yaw center 70 deg/s 10-2000 deg/s More response near center stick. The quad starts rotating with smaller stick movement. Softer center control. Better for slow cruising, tight proximity, and beginners.
Roll expo, pitch expo, yaw expo 20% 0-100% More center softness while keeping high-stick authority. Useful when full-stick flips feel good but small corrections are twitchy. A more linear stick. Useful when the center feels numb or disconnected.
Roll max, pitch max, yaw max 670 deg/s 10-2000 deg/s Faster full-stick rolls, flips, and yaw spins. Good for snappy freestyle once center control is clean. Slower maximum rotation. Good for learning, cinematic lines, and preventing over-rotation.

Controller feel

Controller Feel is the layer between requested rotation and motor output. It is inspired by rate-controller concepts, but these are acroFPV simulator parameters rather than real Betaflight PID numbers.

Slider Default Range What it changes Tuning notes
Rate P gain 1.05 0-2 How hard the craft pushes angular velocity toward the requested roll, pitch, or yaw rate. Higher feels locked-in and urgent. Too high can feel nervous. Lower feels loose, lazy, or late.
Rate damping 0.22 0-1.5 How strongly existing rotation is resisted to reduce bounce, carry-through, and overshoot. Higher makes stops cleaner and more braked. Too high can feel heavy. Lower lets rotations coast more.
Feed forward 0.95 0-2 Immediate acceleration from fast stick movement before normal rate error builds. Higher gives snap at stick changes. Too high can feel jerky. Lower makes the quad wait for error before reacting.
Motor response 18 ms 5-250 ms How quickly simulated motor outputs move toward their target mix. Lower is sharper and more connected. Higher creates prop/motor lag and a heavier delayed feel.

Craft physics

These sliders describe the rigid-body side of the sim. Presets combine them into recognizable classes such as whoops, toothpicks, 3.5 inch freestyle quads, and heavier 5 inch freestyle quads.

Slider Default Range What it changes Tuning notes
Craft weight 840 g 20-1200 g All-up weight used by the thrust model and shown in the active preset summary. Pair it with inertia, thrust-to-weight, and drag. Weight by itself is less important than the whole preset balance.
Thrust-to-weight 6.7x 1.2-12x Maximum thrust relative to hover weight. Approximate hover throttle is 100 divided by this value. Higher gives more punch and recovery authority. Lower makes the quad work harder to climb or save dives.
Rotational inertia 0.10 0.05-3 Resistance to angular acceleration from the controller. Higher resists flips and direction changes. Lower makes the craft rotate and correct aggressively.
Angular drag 0.065 0-2 Airframe resistance against spinning. Higher bleeds off rotation faster. Lower lets rotations carry and can feel more slippery.
Linear drag 0.035 0-3 Baseline resistance against movement through air, based on relative air velocity. Higher slows coasting and makes speed wash away. Lower preserves momentum through dives and exits.
High-speed drag 0.014 0-2 Extra drag that grows with speed. Higher caps fast dives and long runs. Lower keeps high-speed lines faster and more ballistic.

World and FPV camera

These settings change the environment and what your eyes see. Camera angle and FOV can make the same physics feel slow, fast, precise, or sketchy.

Slider Default Range What it changes Tuning notes
Gravity 18 m/s^2 0-20 m/s^2 Downward acceleration. The thrust model scales hover thrust with gravity, so hover throttle mainly stays tied to thrust-to-weight. Higher makes dives and recovery timing more intense. Lower feels floatier and gives more time between corrections.
Wind speed 0 m/s 0-25 m/s Steady environmental wind used to calculate relative air velocity and drag. Raise it when you want drift, correction practice, and less perfectly still lines.
Wind gust 0.15 0-1 Variation added around the wind vector. Higher makes wind less predictable. With wind speed at zero, the effect stays subtle.
Ground effect 0.06 0-1 Extra lift below roughly 2 m above the ground, fading out with height. Higher makes low skims feel cushioned. Lower makes low throttle timing more direct.
Camera angle 35 deg 0-60 deg FPV camera up-tilt on the frame. Higher favors faster forward flight. Lower favors slower proximity, cruising, and indoor-style control.
Camera FOV 80 deg 60-130 deg Perspective field of view. Wider FOV increases speed and proximity perception but adds distortion. Narrower FOV feels calmer and more zoomed-in.

Common tuning moves

Problem Try first Then try
Too twitchy around center stick Lower center sensitivity or raise expo. Lower feed forward slightly, then lower P gain if it still feels nervous.
Stops bounce or carry too far Raise rate damping. Raise angular drag or lower rotational inertia only after rates feel right.
Quad feels delayed Lower motor response time. Raise feed forward or P gain in small steps.
Lines feel too floaty Raise gravity or widen camera FOV. Reduce thrust-to-weight if climbs are too easy, or raise drag if exits carry too far.
Dives are too hard to save Raise thrust-to-weight. Lower gravity or lower high-speed drag if the dive feels abruptly braked.
Speed perception feels wrong Adjust camera angle and FOV before changing physics. Then tune drag and thrust-to-weight while flying the same line.

FAQ

Are these Betaflight PID values?

No. The ACTUAL rate sliders use familiar Betaflight-style terms, but the controller feel and physics sliders are acroFPV simulator parameters. Treat them as a feel model, not a real quad tune export.

Can I copy my real rates?

If your real quad uses ACTUAL rates, center sensitivity, expo, and max rate are reasonable starting points. After that, tune camera angle, FOV, and physics by feel.

Should beginners use this page?

Yes, but lightly. Beginners should start with a preset, learn acro mode, and practice drills. Come back here when a specific feel problem shows up repeatedly.

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