Installing Speed Controllers

This page covers the physical installation of your ESC (Electronic Speed Controller). For how ESCs work and what specs mean, see ESCs.

4-in-1 ESC Installation

Stack Mounting

The 4-in-1 ESC typically goes at the bottom of the stack, directly above the frame’s bottom plate:

1. Place rubber grommets on the standoff screws (optional for ESC, but helps with noise)
2. Set the ESC on the standoffs — align the mounting holes (30.5mm or 20mm pattern)
3. Secure with standoffs or nuts — finger-tight, then gently snug with a nut driver
4. Connect the stack header to the FC if using a plug connector

Motor Wire Soldering

The 4-in-1 ESC has pads labeled for each motor (M1, M2, M3, M4). Each motor has 3 wires.

1. Identify which motor goes to which pad — check Betaflight’s motor diagram and match motor positions to ESC pad labels
2. Trim motor wires to appropriate length — route along the arm and leave enough for a clean path to the ESC pad
3. Tin wires and pads
4. Solder each set of 3 wires to the corresponding motor pads
5. Wire order doesn’t matter (direction can be reversed in BLHeli software)

Battery Lead

Solder the battery pigtail (XT60) to the main power pads (labeled BAT+ and BAT-, or B+ and B-).

→ See Power Distribution for details.

Individual ESC Installation

If using separate ESCs (one per arm):

1. Mount each ESC on its arm — double-sided tape, zip ties, or heat shrink over the arm
2. Solder motor wires directly to each ESC’s motor pads (3 wires per motor)
3. Route power wires from each ESC to a central PDB or directly to the battery lead (parallel connection)
4. Route signal wires from each ESC to the FC’s motor signal pads
5. Protect with heat shrink over exposed boards and connections

Configuration

BLHeli Configurator

After physical installation, configure the ESCs via BLHeli Configurator:

1. Connect the FC via USB
2. Open Betaflight Configurator
3. Open BLHeli Configurator (it connects via passthrough through the FC)
4. The configurator should detect all 4 ESCs

Key Settings

• Motor Direction: Set each motor to the correct direction (Normal or Reversed)
• Motor Timing: Auto (default) works for most builds
• Demag Compensation: High (prevents motor desync during aggressive flying)
• Startup Power: Default unless motors fail to start reliably
• PWM Frequency: 24kHz (default) or 48kHz for smoother response
• Bidirectional DShot: Enable for RPM filtering (if supported by your ESC firmware)

Firmware

• BLHeli_32: Update to the latest version for best performance
• Bluejay: If using BLHeli_S ESCs, flash Bluejay firmware for bidirectional DShot support
• AM32: Open-source alternative for 32-bit ESCs

Testing

After installation, before installing props:

1. Verify in Betaflight Motors tab — each motor should spin when its slider is raised
2. Check direction — compare to Betaflight’s motor diagram
3. Check for vibration — motors should spin smoothly with no grinding or wobble
4. Feel for heat — run motors at 50% for 10 seconds, then check ESC temperature. Should be barely warm.
5. Listen for desyncs — a motor that stutters or stops and restarts has a desync issue (adjust demag, timing, or startup power)