A brushless direct current electric motor assembly, comprising: a housing having a first end and a second end, a stator disposed in the housing; a rotor subassembly disposed in the stator, the rotor subassembly comprising a shaft having a first end proximate the first end of the housing and a second end proximate the second end of the housing; a first cap disposed on the first end of the housing; a second cap disposed on the second end of the housing, the housing enclosed by the first cap and the second cap; wherein the housing comprises a plurality of air inlet openings proximate to the first end and a plurality of air outlet openings proximate to the second end, wherein the housing is substantially tubular between the first end and the second end, and wherein an inner diameter of the housing is between 30 mm and 70 mm; a controller is disposed in the housing between the second cap and the stator and directly mechanically coupled to the stator, the controller configured to control rotation of the shaft, wherein an outer diameter of the controller is less than the inner diameter of the housing, the controller comprising: a printed circuit board assembly (PCBA) having a first side and an opposing second side facing toward the second cap, the PCBA comprising a plurality of electrical components, the plurality of electrical components comprising a microcontroller unit, a plurality of Hall effect sensors, and at least six MOSFETs, wherein at least one of the Hall effect sensors is disposed on the first side and at least one of the MOSFETs is disposed on the second side, the PCBA configured to communicate with and control at least one of a DC battery, a speed control, or a switch; a fan rotationally fixed relative to the shaft, the fan disposed between the first cap and the stator and proximate to the air inlet openings, the fan configured to draw air into an interior portion of the housing through the air inlet openings and toward the air outlet openings for cooling the electrical components during operation; and a conductive ring disposed between the controller and the second cap, the conductive ring configured to transfer heat from the controller to the second cap and to electrically insulate the controller from the second cap, the conductive ring formed from a high voltage and high temperature resistive material; wherein the second cap is configured to operate as a heat sink to draw heat from the MOSFETs; wherein the controller defines a controller bore configured to receive the shaft therethrough; and wherein the first end of the shaft is configured to provide a rotational output. a housing having a first end and a second end, a stator disposed in the housing; a rotor subassembly disposed in the stator, the rotor subassembly comprising a shaft having a first end proximate the first end of the housing and a second end proximate the second end of the housing; a first cap disposed on the first end of the housing; a second cap disposed on the second end of the housing, the housing enclosed by the first cap and the second cap; wherein the housing comprises a plurality of air inlet openings proximate to the first end and a plurality of air outlet openings proximate to the second end, wherein the housing is substantially tubular between the first end and the second end, and wherein an inner diameter of the housing is between 30 mm and 70 mm; a controller is disposed in the housing between the second cap and the stator and directly mechanically coupled to the stator, the controller configured to control rotation of the shaft, wherein an outer diameter of the controller is less than the inner diameter of the housing, the controller comprising: a printed circuit board assembly (PCBA) having a first side and an opposing second side facing toward the second cap, the PCBA comprising a plurality of electrical components, the plurality of electrical components comprising a microcontroller unit, a plurality of Hall effect sensors, and at least six MOSFETs, wherein at least one of the Hall effect sensors is disposed on the first side and at least one of the MOSFETs is disposed on the second side, the PCBA configured to communicate with and control at least one of a DC battery, a speed control, or a switch; a fan rotationally fixed relative to the shaft, the fan disposed between the first cap and the stator and proximate to the air inlet openings, the fan configured to draw air into an interior portion of the housing through the air inlet openings and toward the air outlet openings for cooling the electrical components during operation; and a conductive ring disposed between the controller and the second cap, the conductive ring configured to transfer heat from the controller to the second cap and to electrically insulate the controller from the second cap, the conductive ring formed from a high voltage and high temperature resistive material; wherein the second cap is configured to operate as a heat sink to draw heat from the MOSFETs; wherein the controller defines a controller bore configured to receive the shaft therethrough; and wherein the first end of the shaft is configured to provide a rotational output.