AM32 Power — Forward, Reverse, Full Control The FingerTech BL40A AM32 reversing ESC is a 40A brushless speed controller built for beetleweight combat robots that need full bidirectional control. Running FingerTech’s own customized AM32 firmware, it delivers faster response, better low-end torque, and more efficient power delivery than BLHeli equivalents. Whether you’re driving brushless drive motors or running a reversible weapon, this ESC handles it cleanly. 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 response and low-end torque for the demands of drive 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 motors. Drive Motor Use The reversing ESC is the right choice for brushless drive systems. Pair it with FingerTech‘s Mega Spark Brushless Gearmotors — available in 750KV, 1500KV, and 2300KV variants — or with other manufacturers’ brushless drive motors. You’ll need two reversing ESCs for a standard two-motor drive system. Reversible Weapon Use Need the option to reverse your weapon direction? The reversing ESC works with the F4006 740KV Brushless Outrunner and S2838 2970KV Brushless Inrunner, as well as other manufacturers’ brushless weapon motors. For standard single-direction weapon use, the FingerTech BL40A AM32 ESC is the more common choice — see the FAQ tab for more on why. Wiring Notes The BL40A reversing ESC 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 in the wrong direction, swap any two wires. The NightWing kit uses this ESC for drive motors, paired with the NightWing Electronics Kit — all wiring is documented in the NightWing build instructions. Standard vs Reversing Not sure which version you need? The standard FingerTech BL40A AM32 ESC is single-direction — ideal for weapon motors that only spin one way. This reversing version is programmed for both forward and reverse, making it the right choice for drive motors or any application where bidirectional control matters. The hardware and specs are otherwise identical.
