Betaflight Anti-Gravity and I-Term Relax: Tuning for Smooth Freestyle Control

Q: Should I use I-Term Relax on a racing quad?

Yes — but use the Setpoint type instead of Gyro. Setpoint detection cuts I-term based on your stick input rate rather than gyro rate, which feels more direct for racing. Racers also typically run a higher cutoff (18-25 Hz) for less intervention.

# Betaflight Anti-Gravity and I-Term Relax: Tuning for Smooth Freestyle Control

Anti-Gravity and I-Term Relax are two of the most misunderstood features in Betaflight — yet they are also two of the most powerful. Together, they eliminate the bobbing, bouncing, and washout that plague aggressive freestyle flying without touching your main PID gains.

This guide explains exactly how these features work, when to use them, and how to dial them in for buttery-smooth freestyle control.

## What Is I-Term and Why Does It Need Help?

The I-term (Integral) in a PID controller accumulates error over time. Its job is to correct steady-state offsets — like the quad drifting in a hover or sagging during a sustained turn. The problem: I-term can accumulate too much error during rapid throttle changes, causing the quad to lurch or bounce when you punch out or chop throttle.

This is where Anti-Gravity and I-Term Relax come in.

## Anti-Gravity: I-Term Boost on Fast Throttle Moves

Anti-Gravity temporarily boosts the I-term gain whenever it detects rapid throttle movement. The faster you punch the throttle, the stronger the boost — up to the configured gain multiplier.

**What it fixes**:
– Quad bobbing/dipping on rapid punch-outs
– Pitch-back on full-throttle climbs
– Nose-dropping when chopping throttle to zero

### Anti-Gravity Settings

| Parameter | Default | Range | Effect |
|———–|———|——-|——–|
| Anti-Gravity Gain | 3.5 (BF 4.3+) | 1.0 – 20.0 | Higher = stronger I-term boost on throttle change |
| Anti-Gravity Activation Threshold | 1350 | 1200 – 1800 | Throttle change rate that triggers boost |

**How to tune Anti-Gravity Gain**:

1. Start at default (3.5 for Betaflight 4.3+)
2. Perform aggressive punch-outs and throttle chops
3. Increase by 0.5 if you see bobbing or dip
4. Decrease by 0.5 if the quad feels “stiff” or oscillates during throttle changes
5. Most 5-inch freestyle builds land between 3.5 and 6.0

**Warning**: Too much Anti-Gravity gain causes I-term oscillation when rapidly cycling throttle. If your motors sound “angry” during throttle pumps, back it down.

## I-Term Relax: Cutting I-Term at Low Authority

I-Term Relax reduces (relaxes) the I-term when it would be least effective — specifically at low throttle where the motors have minimal authority. Without I-Term Relax, the I-term continues accumulating error even when the quad can’t physically correct it, causing bounce-backs and landing instability.

**What it fixes**:
– Bounce-back after rolls and flips (the quad overshoots then snaps back)
– Jerky landings and ground-effect wobbles
– I-term windup during zero-throttle maneuvers (inverted hang time)

### I-Term Relax Settings

**I-Term Relax Types**:

**How to tune I-Term Relax**:

1. Leave Type on “Gyro” for freestyle
2. Start at default Cutoff (15 Hz)
3. If you experience bounce-backs after flips, lower cutoff to 10-12 Hz for more aggressive I-term cutting
4. If the quad feels “loose” at the end of maneuvers, raise cutoff to 18-20 Hz

## Anti-Gravity + I-Term Relax: The Perfect Pair

These two features work together beautifully. Anti-Gravity handles the I-term response DURING rapid throttle changes, while I-Term Relax handles the I-term recovery AFTER moves. Together, they eliminate the two most common I-term artifacts.

### Tuning Workflow

## Common Problems and Fixes

## Advanced: Anti-Gravity Per Profile

If you fly both freestyle and racing on the same quad, set up different Rate Profiles with different Anti-Gravity values:

## Product Recommendation

A responsive flight controller with low-noise gyro makes Anti-Gravity and I-Term Relax work even better. Check out the **[F7 flight controllers at uavmodel.com](https://uavmodel.com)** — their fast processors and ICM-42688-P gyros provide the clean gyro data these features need to work flawlessly.

## Anti-Gravity and I-Term Relax Explained

## Frequently Asked Questions

### What is the difference between Anti-Gravity and throttle-based I-term scaling?
Anti-Gravity dynamically boosts I-term based on the RATE of throttle change, while traditional throttle-based I-term scaling applies a multiplier at a fixed throttle position. Anti-Gravity is more responsive because it reacts to how fast you move the stick, not just where it is.

### Should I use I-Term Relax on a racing quad?
Yes — but use the “Setpoint” type instead of “Gyro.” Setpoint detection cuts I-term based on your stick input rate rather than gyro rate, which feels more direct for racing. Racers also typically run a higher cutoff (18-25 Hz) for less intervention.

### Does Anti-Gravity work with throttle limit / throttle cut?
Anti-Gravity detects the throttle signal as sent to the motors, not your stick position. If you have a throttle limit set (e.g., 80%), Anti-Gravity still responds to the rate of change within that limited range — it will just be proportionally weaker.

### Can I use Anti-Gravity and I-Term Relax on Betaflight 3.5?
Anti-Gravity was introduced in Betaflight 3.4 and is available in 3.5+. I-Term Relax was introduced in Betaflight 4.1. Upgrade to at least Betaflight 4.3 for the most refined implementations of both features.

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