ODrive Motors

Below is general characteristics and performance numbers of the motors sold on the ODrive shop. Note that all performance figures are approximate, and real-world performance will depend on your particular application and cooling solution.

Motor Characteristics

M8325s 100KV

Specification	Value	Unit	Notes
Speed Constant	100	RPM/V [1]
Torque Constant	0.083	Nm/A [2]
Speed / Torque Gradient	43.53	RPM/Nm
Pole Pairs	20
Phase Resistance	24	mΩ	Phase-neutral
Phase Inductance	9.9	uH	Phase-neutral
Continuous Current	40 60	A A	Free Air Forced Air
Peak Current	80	A	3-second
Thermistor	NTC 10k 3435

D6374 150KV

Specification	Value	Unit	Notes
Speed Constant	150	RPM/V [1]
Torque Constant	0.055	Nm/A [2]
Speed / Torque Gradient	159.54	RPM/Nm
Pole Pairs	7
Phase Resistance	39	mΩ	Phase-neutral
Phase Inductance	24	uH	Phase-neutral
Continuous Current	50 70	A A	Free Air Forced Air
Peak Current	90	A	3-second
Thermistor	NTC 10k 3435

D5065 270KV

Specification	Value	Unit	Notes
Speed Constant	270	RPM/V [1]
Torque Constant	0.031	Nm/A [2]
Speed / Torque Gradient	515.67	RPM/Nm
Pole Pairs	7
Phase Resistance	39	mΩ	Phase-neutral
Phase Inductance	16	uH	Phase-neutral
Continuous Current	45 65	A A	Free Air Forced Air
Peak Current	85	A	3-second
Thermistor	NTC 10k 3435

D5312s 330KV

Specification	Value	Unit	Notes
Speed Constant	330	RPM/V [1]
Torque Constant	0.025	Nm/A [2]
Speed / Torque Gradient	730.83	RPM/Nm
Pole Pairs	7
Phase Resistance	37	mΩ	Phase-neutral
Phase Inductance	23	uH	Phase-neutral
Continuous Current	30 50	A A	Free Air Forced Air
Peak Current	60	A	3-second
Thermistor	NTC 10k 3435

NEMA 34 Servomotor w/ 16384 CPR Absolute Encoder

Specification	Value	Unit	Notes
Speed Constant	87	RPM/V [1]
Torque Constant	0.095	Nm/A [2]
Speed / Torque Gradient	81.00	RPM/Nm
Pole Pairs	4
Phase Resistance	59	mΩ	Phase-neutral
Phase Inductance	140	uH	Phase-neutral
Continuous Current	20	A	Free Air
Peak Current	40	A	3-second
Thermistor	NTC 10k 3950
Integrated Encoder	AMT212B-V-OD

• [1] All voltage units are line-line amplitude

• [2] All current units are phase amplitude

Torque-Speed Curves

Because brushless motors are current-limited devices, the torque-speed curve looks quite different than what many people are used to when dealing with brushed motors.

Specifically, the motor is able to operate at a constant torque for the vast majority of its speed range, with the specific torque determined by the motor’s torque constant and current rating. However, after a certain speed (“base speed”), the achievable torque linearly falls to zero as the motor reaches its no-load speed (“free speed”). An example of such a graph is below, however the exact response will differ based on the motor parameters.

Approximate torque-speed curves for various motors can be created with this calculator. The x-axis is the motor’s speed (in RPM), and the y-axis is the motor’s torque (in Nm). The green dotted line is the motor’s peak torque output, and the red solid line is the motor’s continuous torque output. Note this is only a rough model of motor behavior, intended as a guide for motor and ODrive selection — your real-world results may vary!

The default values in the calculator are for the ODrive D6374 150KV with an ODrive S1. To configure the plot for a different motor or ODrive:

• Set \(K_{v}\) to the motor’s speed constant, in RPM/V.

• Set \(R_{phase}\) to the motor’s phase-neutral resistance, in ohms (e.g. 24 mΩ = 0.024 Ω).

• Set \(V_{bus}\) to your DC bus voltage, in volts.

• Set \(M_{max}\) to your ODrive’s maximum modulation depth. * This is typically 0.78 for ODrive S1 and ODrive Micro, and 0.99 for ODrive Pro.

• Set \(I_{peak}\) and \(I_{cont}\) to your motor’s peak and continuous current, in amps.

For instance, the below graph simulates an ODrive S1 + D6374 150KV with a 48V bus voltage.

We can see that the motor can output a continuous torque of about 2.756 Nm from zero speed to about 5,177 RPM (the “base speed”). From there, the achievable torque falls linearly approaching a free speed of 5,616 RPM. At its peak output (during short periods of time and intermittent operation), the motor can output about 4.96 Nm from zero speed to about 4,826 RPM, after which the achievable torque also falls linearly to the free speed of 5,616 RPM.