You punch the throttle and your quad pitches back 15 degrees. You drop into your own prop wash and the quad oscillates like it’s having a seizure. Neither of these are PID problems — they’re I-term problems. Anti-Gravity and I-Term Relax are the two features Betaflight added specifically to solve these, and most pilots don’t understand how either one actually works.
Step-by-Step: Configure Anti-Gravity and I-Term Relax
1. Understand What I-Term Actually Does
I-term is the “memory” of your PID controller. It accumulates error over time and applies a correction that grows until the error is eliminated. This is what holds your quad’s attitude against wind, off-center CG, and bent props.
The problem: when you punch the throttle, motor RPM spikes instantly. The I-term was accumulated for steady-state hover or cruise — it doesn’t predict the sudden torque change. Result: the quad pitches or rolls in the direction of motor torque, and the I-term takes 100–300ms to “catch up” to the new flight state.
Anti-Gravity temporarily boosts I-term during rapid throttle changes so it corrects the torque-induced attitude shift faster. I-Term Relax does the opposite — it suppresses I-term accumulation during fast stick movements (like flips and rolls) to prevent I-term windup and bounce-back at the end of the maneuver.
2. Tune Anti-Gravity Gain
Default Anti-Gravity gain is 3.5 in Betaflight 4.5. This is conservative. For most 5-inch builds, you can go higher.
- Set Anti-Gravity gain to 3.5 (default)
- Fly a punch-out from hover to full throttle. Watch the quad’s attitude.
- If it pitches back (nose rises) during the punch, increase Anti-Gravity by 0.5
- If it oscillates during the punch, you’ve gone too high — decrease by 0.5
- Repeat until the quad stays locked in attitude through the entire throttle range
Typical values:
– Lightweight 3-inch: 2.5–3.0
– 5-inch freestyle (4S): 3.5–4.5
– 5-inch freestyle (6S, high torque): 4.0–5.5
– 7-inch long range: 3.0–4.0
– Cinewhoop (heavy, low authority): 5.0–7.0
Verification: Record DVR. Frame-by-frame, the horizon should stay level during a full-throttle punch from hover. Any pitch/roll deviation that takes more than 200ms to correct means Anti-Gravity is too low.
3. Set I-Term Relax Cutoff
I-Term Relax has two parameters: cutoff frequency and relax type.
- iterm_relax_cutoff: Default 15Hz. This is the gyro frequency below which I-term relax engages. At 15Hz, it activates for flips/rolls (~2-5Hz) but stays off for prop wash (~50-150Hz). You generally don’t need to change this.
- iterm_relax_type: RP (roll+pitch) or RPY (roll+pitch+yaw). RP is default and correct for 99% of builds. Yaw doesn’t need I-term relax unless you’re doing sustained pirouettes.
Don’t overthink this setting. If you get bounce-back at the end of flips and rolls (a fast wobble as the quad settles), decrease the cutoff to 10Hz (wider relax window). If the quad feels loose during fast flips, increase to 20Hz (narrower window).
Anti-Gravity and I-Term Relax: Parameter Interaction Matrix
| Parameter | Default | What It Does | Too Low | Too High | Best For |
|---|---|---|---|---|---|
| Anti-Gravity Gain | 3.5 | Boosts I-term during rapid throttle change | Pitch-back on punch-outs | High-frequency oscillation on throttle | 5-inch 6S: 4.5. Light builds: 3.0. |
| I-Term Relax Cutoff | 15 Hz | Suppresses I-term below this gyro frequency | Bounce-back after flips | Loose, imprecise stops | Default 15Hz. Adjust ±5Hz max. |
| I-Term Relax Type | RP | Axes to apply relax | Yaw windup during fast yaw spins | Unnecessary if no yaw issues | RP for everyone. RPY for sustained pirouettes. |
| I-Term Windup (limit) | 400 | Hard cap on I-term accumulation | Windup stalls near limit | I-term too aggressive overall | Default 400. Raise to 500 if hitting the cap. |
| Throttle PID Attenuation (TPA) | 0.65/1350 | Reduces P/D at high throttle | Prop wash oscillation above 70% throttle | Mushy top-end response | Start at 0.65/1350. Adjust if prop wash only at high throttle. |
What Most Pilots Get Wrong
Mistake 1: Treating Anti-Gravity as a “stability” setting. Anti-Gravity is specifically for throttle-induced torque compensation. It doesn’t make your quad more stable in wind or prop wash. Cranking it to 10 thinking it’ll fix a bad tune just introduces high-frequency jitter on throttle changes. Fix your PIDs first, then use Anti-Gravity to clean up the remaining pitch-back.
Mistake 2: Disabling I-Term Relax because “I want maximum I-term authority.” Without I-Term Relax, every fast flip or roll accumulates I-term error during the maneuver. When you center the stick, the accumulated I-term slams the quad in the opposite direction — bounce-back. I-Term Relax pauses I-term accumulation during fast rotation so the I-term value is correct for the post-maneuver attitude, not the mid-maneuver error.
Mistake 3: Changing both Anti-Gravity and I-Term Relax at the same time. These are independent mechanisms solving different problems. Anti-Gravity is throttle-driven; I-Term Relax is gyro-rate-driven. If you change both simultaneously and the quad feels different, you won’t know which change caused the effect. Tune one at a time.
Mistake 4: Using Anti-Gravity to mask excessive D-term. If your D-term is too low, the quad will have prop wash oscillations regardless of Anti-Gravity. Anti-Gravity’s I-term boost can partially mask this by stiffening attitude hold, but the root cause (insufficient damping) remains. Raise D-term first, then fine-tune with Anti-Gravity.
Mistake 5: Skipping Anti-Gravity tuning on a 6S build. 6S builds have dramatically higher motor torque than 4S — the torque-induced attitude shift on a throttle punch is proportionally larger. A 6S 5-inch with default Anti-Gravity 3.5 will pitch back noticeably. Bump to 4.5 minimum for 6S builds, and 5.0+ for high-KV 6S setups.
⚠️ Regulatory Notice: The flight tuning recommendations in this article should be followed in accordance with the latest 2026 drone regulations in your country or region. Always verify local laws regarding flight altitude, no-fly zones, remote ID requirements, and registration before flying. Regulations vary significantly between the FAA (US), EASA (EU), CAA (UK), CAAC (China), and other authorities.
Our Betaflight PID Tuning Guide covers the full PID loop — Anti-Gravity and I-Term Relax are the finishing touches after your P, I, and D values are dialed in. And if you’re seeing oscillations at high throttle specifically, our FPV Drone Prop Wash Oscillation Fix covers TPA and dynamic damping.
For 6S freestyle builds that demand aggressive Anti-Gravity tuning without introducing jitter, the uavmodel F722 flight controller runs an F7 processor with enough headroom for 8kHz PID loops plus dynamic filtering — so your I-term calculations are never CPU-starved during rapid throttle transients.