Motors

✓ CAN Bus✓ Dual Encoder✓ Integrated Driver✓ Planetary Reduction

I2RT's GF series are all-in-one joint modules — planetary gearbox, brushless DC motor, and driver integrated into a single compact housing. Gears are vacuum-nitrided for high strength and service life. The concentrated-winding motor design delivers high power density with optimized pole-arc ratio for low cogging torque and smooth motion.

Model Comparison

Model	Reduction Ratio	Rated Torque	Peak Torque	Rated Speed	Weight	Size (⌀ × L)
GF43X40-16	40	14 N·m	23.5 N·m	44 RPM	464.5 g	57 × 62.5 mm
GF43X40-10	40	8.9 N·m	28 N·m	43 RPM	362 g	57 × 56.5 mm
GF43X10-10	10	2.2 N·m	7 N·m	172 RPM	300 g	57 × 45.9 mm

All models share the same 24 V supply and CAN bus interface.

Key Features

Dual encoder — single-turn absolute output-shaft position; survives power-off without losing zero reference
Integrated driver — compact single-unit assembly with no external controller required
CAN bus feedback — real-time speed, position, torque, and motor temperature
Dual temperature protection — hardware and software over-temperature shutdown
Trapezoidal motion profile — configurable acceleration/deceleration in position mode
Visual debugging — host-PC GUI for tuning and firmware upgrade

Communication

All GF series motors communicate over CAN bus (1 Mbit/s), the same bus used by YAM arm actuators. Multiple motors can share a single CAN channel using standard node addressing.

Naming Convention

GF  43  X  40  -  16
│   │      │      └─ Motor variant (current/winding spec)
│   │      └─────── Reduction ratio
│   └────────────── Outer diameter class (43 mm motor stator)
└────────────────── GF joint module series

Hardware Setup

Using a motor standalone for development or testing.

Prerequisite

Finish SW Setup first.

1. Inventory

[ ] Motor
[ ] Motor cable (CAN + power)
[ ] CANable USB-CAN adapter
[ ] 24 V or 48 V power supply (check motor label)

2. Wire it up

[ ] Connect the motor's CAN cable to your CANable adapter
[ ] Connect the motor's power input to the supply
[ ] Plug the CANable into the host PC's USB

3. Bring up CAN

bash

sudo ip link set can0 up type can bitrate 1000000
ls -l /sys/class/net/can*

4. (If needed) Set the motor ID

Each motor needs a unique ID on the bus (1–6 for YAM, custom for standalone).

bash

python i2rt/motor_config_tool/set_id.py --channel can0 --old-id 1 --new-id 2

5. (If needed) Zero the motor offset

bash

python i2rt/motor_config_tool/set_zero.py --channel can0 --motor_id 1

Quick Start Demo

Read motor state

python

from i2rt.motor_drivers.dm_driver import DMChainCanInterface, MotorType

motor_chain = DMChainCanInterface(
    motor_list=[(1, MotorType.DM4310)],
    motor_offsets=[0.0],
    motor_directions=[1],
    channel="can0",
)

state = motor_chain.read_states()
print(state)
# JointState(pos=..., vel=..., eff=..., temp_mos=..., temp_rotor=...)

MIT-mode position command

python

import numpy as np

# Command motor 1 to position 0 rad with PD gains
motor_chain.set_commands(
    kp=np.array([5.0]),
    kd=np.array([0.5]),
    pos=np.array([0.0]),
    vel=np.array([0.0]),
    torque=np.array([0.0]),
)

Safety timeout

By default each motor has a 400 ms safety timeout. If no command arrives for 400 ms, the motor switches to damping mode automatically. Disable only when you have a reliable PD loop running — see the Set safety timeout section below.

For a full interactive PD-control teleop example (arrow-key control, live state display), see the Single Motor PD Control section below.

Single Motor PD Control

Location: examples/single_motor_position_pd_control/

The simplest possible example — command a single DM-series motor to a target position with a PD controller. Useful for testing new hardware, debugging CAN connectivity, or learning the motor driver API.

Running

bash

python examples/single_motor_position_pd_control/single_motor_position_pd_control.py \
  --channel can0 --motor_id 1 --motor_type DM4340 --kd 3

Argument	Default	Description
`--channel`	`can0`	CAN interface name
`--motor_id`	`1`	Motor ID on the bus (1–7 typical)
`--motor_type`	`DM4340`	Motor model: `DM4310`, `DM4340`, `DM6248`, `DM3507`
`--kp`	`80.0`	Proportional gain
`--kd`	`3.0`	Derivative gain
`--rate_hz`	`200.0`	Control loop rate
`--step`	`0.01`	Step size per arrow key press (rad)

The interactive panel shows live motor state:

Arrow-key PD teleop (q to quit)
Current pos : -1.64359 rad
Target  pos : -1.49720 rad
Velocity    : -0.00244 rad/s
Torque      : +11.65812 Nm
Temp rotor  : 45.0 °C   Temp MOS: 35.0 °C

Step size   : 0.01000 rad   (↑ bigger / ↓ smaller)
KP=80.00  KD=3.00

Controls: ←/→ move • r reset-to-current • SPACE hold • q quit

Keyboard Controls

Key	Action
`←` / `→` (or `h` / `l`)	Decrease / increase target position
`↑` / `↓` (or `k` / `j`)	Increase / decrease step size
`r`	Reset target to current position
`Space`	Hold current position
`q` / `ESC`	Quit

Example Code

The example wraps a single motor in a DMChainCanInterface and runs a PD position loop:

python

from i2rt.motor_drivers.dm_driver import DMChainCanInterface

motor_list = [[1, "DM4340"]]            # [(motor_id, motor_type), ...]
motor_directions = [1]
chain = DMChainCanInterface(
    motor_list, [0], motor_directions, channel="can0", receive_mode="p16"
)

states = chain.read_states()             # current pos / vel / torque
chain.set_commands([{"pos": 0.0, "kp": 80.0, "kd": 3.0}])

chain.close()

Motor Configuration Tools

One-time motor configuration utilities live in i2rt/motor_config_tool/. When --motor_id is omitted, all three commands operate on motors 1–7 on the bus by default — pass an explicit --motor_id N to target a single motor.

Ping motors

bash

# Ping every motor on can0 (IDs 1–7)
python i2rt/motor_config_tool/ping_motors.py --channel can0

# Ping motor 3 only
python i2rt/motor_config_tool/ping_motors.py --channel can0 --motor_id 3

Zero motor offset

bash

# Zero every motor on can0 (run with the arm in its mechanical zero pose)
python i2rt/motor_config_tool/set_zero.py --channel can0

# Zero motor 1 only
python i2rt/motor_config_tool/set_zero.py --channel can0 --motor_id 1

Set safety timeout

bash

# Disable the 400 ms motor safety timeout (default)
python i2rt/motor_config_tool/set_timeout.py --channel can0

# Re-enable the safety timeout
python i2rt/motor_config_tool/set_timeout.py --channel can0 --timeout

Power cycle required

After running set_zero.py or set_timeout.py, power-cycle the motor for the new configuration to take effect.

YAM Arm Series

Motors

Model Comparison

Key Features

Communication

Naming Convention

Hardware Setup

1. Inventory

2. Wire it up

3. Bring up CAN

4. (If needed) Set the motor ID

5. (If needed) Zero the motor offset

Quick Start Demo

Read motor state

MIT-mode position command

Single Motor PD Control

Running

Keyboard Controls

Example Code

Motor Configuration Tools

Ping motors

Zero motor offset

Set safety timeout

See Also

Motors ​

Model Comparison ​

Key Features ​

Communication ​

Naming Convention ​

Hardware Setup ​

1. Inventory ​

2. Wire it up ​

3. Bring up CAN ​

4. (If needed) Set the motor ID ​

5. (If needed) Zero the motor offset ​

Quick Start Demo ​

Read motor state ​

MIT-mode position command ​

Single Motor PD Control ​

Running ​

Keyboard Controls ​

Example Code ​

Motor Configuration Tools ​

Ping motors ​

Zero motor offset ​

Set safety timeout ​

See Also ​

Motors

Model Comparison

Key Features

Communication

Naming Convention

Hardware Setup

1. Inventory

2. Wire it up

3. Bring up CAN

4. (If needed) Set the motor ID

5. (If needed) Zero the motor offset

Quick Start Demo

Read motor state

MIT-mode position command

Single Motor PD Control

Running

Keyboard Controls

Example Code

Motor Configuration Tools

Ping motors

Zero motor offset

Set safety timeout

See Also