FingerTech BL40A AM32 ESC
FingerTech BL40A AM32 Brushless ESC
The FingerTech BL40A AM32 ESC brings serious brushless power to your beetleweight weapon system — 40A continuous, 3S–6S compatible, and running FingerTech‘s own optimized AM32 firmware for faster spin-ups and better low-end torque than BLHeli. Purpose-built for combat, it’s the ESC that keeps your weapon spinning when it matters most. Pair it with the F4006 or S2838 weapon motor and go!
$35.99
9 in stock (can be backordered)
AM32 Power for Serious Weapon Builds
The FingerTech BL40A AM32 ESC is a 40A brushless speed controller built for beetleweight combat robots. Running FingerTech’s own customized AM32 firmware, it delivers faster spin-ups, better low-end torque, and more efficient power delivery than BLHeli equivalents. If you’re driving a high-demand weapon motor and need an ESC that can keep up, this is it.
Why AM32?
AM32 is a modern open-source firmware platform designed specifically for brushless motor control. FingerTech has taken AM32 and tuned it for combat robotics — optimizing spin-up routines and low-end response for the demands of weapon systems. The result is an ESC that responds faster and more predictably than the BL20A BLHeli ESC it replaces, with twice the current capacity for larger, more demanding weapon motors.
Compatible Motors
The BL40A is the recommended ESC for FingerTech’s primary beetleweight weapon motors. Pair it with the F4006 740KV Brushless Outrunner for the NightWing undercutter weapon system, or drive the S2838 2970KV Brushless Inrunner for beater bar and similar weapon configurations. Both motors demand more current than smaller ESCs can reliably deliver — the BL40A handles them without breaking a sweat.
Drive Motor Use
Need a single-direction drive ESC for a high-power brushless drive system? The BL40A works here too, though most beetleweight drive applications will want the reversing version instead. For reversible weapon direction or brushless drive, see the FingerTech BL40A AM32 Reversing ESC.
Wiring Notes
The BL40A has no onboard BEC — you’ll need a dedicated 5V BEC to power your receiver. Connect the three motor wires in any order; if the motor spins backwards, swap any two wires. The NightWing kit uses this ESC paired with the NightWing Electronics Kit — all wiring is documented in the NightWing build instructions.
Drive with Mega Spark
Running a brushless drive system? The BL40A pairs well with FingerTech‘s Mega Spark Brushless Gearmotors — available in 750KV, 1500KV, and 2300KV variants. For drive applications you’ll want the reversing version of this ESC.
Features
- 40A continuous / 45A burst — handles high-demand beetleweight weapon motors
- FingerTech-optimized AM32 firmware optimized for faster spin-ups than BLHeli
- 3S–6S LiPo compatible — powers the FingerTech BL40A AM32 ESC across a wide voltage range
- Compact and lightweight — 1.46in × 0.49in × 0.26in, 0.43oz (12.1g)
- 3.5mm bullet connectors — direct fit for most brushless combat motor wires
- Single-direction weapon control — use a reversing version for drive or reversible weapons
Specifications
| Specification | Value |
|---|---|
| Length | 1.46in (37.0mm) |
| Width | 0.49in (12.4mm) |
| Height | 0.26in (6.5mm) |
| Weight | 0.43oz (12.1g) |
| Voltage Range | 11.1–22.2V (3S–6S LiPo) |
| Continuous Current | 40A |
| Burst Current | 45A (<10 seconds) |
| Firmware | AM32 (FingerTech optimized) |
| Motor Connector | 3.5mm female bullet connectors |
| Motor Wire Length | 3.15in (8.0cm) |
| BEC | None — external 5V BEC required |
| Direction | Single direction (forward only) |
Frequently Asked Questions
What's the difference between the BL40A and the BL20A?
The BL40A runs AM32 firmware vs the BL20A's BLHeli, and delivers twice the current capacity — 40A continuous vs 20A. AM32 provides faster spin-ups and better low-end torque, making it the right choice for larger weapon motors like the F4006 and S2838 that can exceed the BL20A's current limits during spin-up.
What's the difference between the BL40A and the BL40A Reversing?
The standard BL40A is single-direction — ideal for weapon motors that only need to spin one way. The reversing version is programmed for both forward and reverse, making it the right choice for drive motors or weapon systems where you want the option to reverse direction. The hardware and specs are otherwise identical.
Does the BL40A have a BEC?
No — there is no onboard BEC. You'll need a dedicated 5V BEC to power your receiver. This is common on higher-current ESCs and keeps power clean for noise-sensitive radio equipment.
Which motors is the BL40A recommended for?
The BL40A is the recommended ESC for the F4006 740KV Brushless Outrunner and the S2838 2970KV Brushless Inrunner. Both motors can exceed the current limits of smaller ESCs during weapon spin-up — the BL40A handles them reliably.
Can I reprogram the BL40A?
Yes — the BL40A runs AM32 firmware and can be reprogrammed using a USB AM32 programmer. FingerTech ships it with optimized settings for combat robotics use, so most builders won't need to change anything out of the box. Advanced users can tune parameters like motor KV, timing, and braking to suit their specific setup.
