# Betaflight Throttle Limit and Motor Output Limit: Setup for Beginners and Racing
Throttle limit and motor output limit are Betaflight features that cap your drone’s maximum power. Whether you want to tame a 6S beast for a smaller flying spot, protect your ESCs from overcurrent, or comply with race class regulations, this guide covers every configuration option.
## Throttle Limit vs Motor Output Limit: The Difference
These two features sound similar but work very differently:
| Feature | What It Does | CLI Command |
|———|————-|————-|
| Throttle Limit | Scales the RC throttle channel before it enters the PID loop | `throttle_limit_type` + `throttle_limit_percent` |
| Motor Output Limit | Scales the final motor output after the PID loop | `motor_output_limit` |
| Scenario | Use |
|———-|—–|
| Beginner learning on 6S | Throttle Limit (linear scaling) |
| Race class compliance (250mW VTX + motor cap) | Motor Output Limit |
| Protecting ESCs from overcurrent | Motor Output Limit |
| Flying a 5-inch in a tight bando | Throttle Limit |
| Reducing top speed without affecting PID | Motor Output Limit |
## Throttle Limit Configuration
Throttle Limit scales the incoming RC throttle command. A 75% throttle limit means full stick deflection produces 75% of max throttle. Simple and predictable.
### CLI Setup
“`
set throttle_limit_type = SCALE
set throttle_limit_percent = 75
“`
| throttle_limit_percent | Effect | Best For |
|————————|——–|———-|
| 90% | Subtle cap, still fast | Experienced pilots in tight spots |
| 80% | Noticeably tamer | Intermediate training |
| 70% | Significantly reduced top speed | Beginners on 6S |
| 60% | Very limited power | First flights, indoor testing |
| 50% | Half power | Bench testing, absolute beginners |
### Scale vs Clip
“`
set throttle_limit_type = SCALE # Proportionally scales the entire throttle range
set throttle_limit_type = CLIP # Caps throttle at limit, full range below
“`
**SCALE** (recommended): The entire stick range is compressed. 50% stick = 37.5% throttle. Smooth and natural feel.
**CLIP**: Throttle behaves normally below the limit, then flatlines. Less natural but keeps low-end resolution intact.
## Motor Output Limit Configuration
Motor Output Limit applies after the PID loop and mixer. It caps motor signals regardless of what the PID loop commands, ensuring hardware protection.
“`
set motor_output_limit = 80
“`
| motor_output_limit | Effect |
|——————-|——–|
| 100 | No limit (default) |
| 90 | 10% headroom for PID corrections |
| 80 | Significant cap, protects borderline ESCs |
| 70 | Aggressive limit, race class compliance |
### Race Class Compliance Example
Many spec racing classes require a motor output limit:
“`
# Example: Spec Class 5-inch Racing
set motor_output_limit = 75
“`
This ensures all racers share a similar top speed, making the race about pilot skill rather than motor and ESC selection.
### ESC Protection
If you are running a setup where motors can pull more amps than your ESCs are rated for:
| Motor Max Draw | ESC Rating | Recommended motor_output_limit |
|—————-|———–|——————————-|
| 45A | 40A | 90 |
| 55A | 45A | 82 |
| 65A | 50A | 78 |
| 40A | 35A | 88 |
The formula: `motor_output_limit = (ESC_rating / motor_max_draw) × 100`
**Critical**: Motor Output Limit does not replace proper ESC selection. It is a safety net. If you consistently need >15% limiting, upgrade your ESCs.
## Throttle Mid and Expo
Combine Throttle Limit with Throttle Mid and Expo for fine control:
“`
set throttle_limit_percent = 75
set thr_mid = 50
set thr_expo = 25
“`
| Parameter | Function | Beginner | Intermediate | Expert |
|———–|———-|———-|————-|——–|
| thr_mid | Stick position for 50% throttle | 50 | 40 | 35 |
| thr_expo | Curve shape around thr_mid | 30 | 20 | 10 |
Higher `thr_mid` and `thr_expo` give more resolution around hover, making altitude control easier for beginners.
## Using Both Together
For maximum control (beginner on 6S in a tight park):
“`
set throttle_limit_type = SCALE
set throttle_limit_percent = 70
set motor_output_limit = 85
set thr_mid = 50
set thr_expo = 30
“`
This provides:
– 70% max throttle via stick scaling (predictable feel)
– 85% motor cap as a hard ceiling (ESC safety)
– Smooth mid-throttle curve with extra resolution around hover
## Adjustment Modes
For more flexibility, assign Throttle Limit to a switch using Adjustment Ranges:
1. Go to the **Adjustments** tab in Betaflight Configurator
2. Add a range: **RC Rate Profile Selection** on a 3-position switch
3. Or use the CLI for a dedicated slider:
“`
set throttle_limit_type = SCALE
set throttle_limit_percent = 100
“`
4. In Adjustments tab, configure “Throttle Limit Percent” on a dial or slider (AUX channel)
This lets you change power limits in flight — perfect for transitioning from open field to tight proximity.
## Hardware for Accurate Limiting
Motor output limiting relies on accurate ESC telemetry. The **UAVModel F7 Ultimate Stack** with **Bluejay 48kHz ESCs** provides real-time RPM and current data, allowing you to verify your motor output limit is working correctly through the OSD. The 65A rated ESCs also mean you rarely need to limit for protection — but the feature is there when you want to tame the beast. Check it out at [uavmodel.com](https://uavmodel.com).