Lincoln Electric Classmate Laser

le_classmate_ros

The Lincoln Electric Classmate Laser is a compact, all-in-one laser welding cell designed specifically for educational environments to train students in advanced laser welding technologies. It features integrated laser and robotic technology on a mobile cart, along with an arc welding torch.

The network diagram for the setup at MFI is shown below:

The LE Classmate is capable of producing additively manufactured parts. A video showing the classmate using this ROS package to write out the letter ‘MFI’ is shown below.

Software Architecture

The le_classmate_ros package is an application software to handle peripheral control and process complex inputs. In the standard ROS-I architecture, it will be the top abstracted layer as shown.

le_classmate_ros Package

This package provides a ROS-compatible control layer for a Fanuc-driven Lincoln Electric Classmate welding cell. It enables service-based control of welding operations via comet_rpc, conversion of CAD geometries into robot trajectories, and execution of coordinated laser or arc weld paths.

Features

• ROS service interface for laser and arc welding control

• DXF-based trajectory generation for weld paths

• Integration with comet_rpc for direct I/O-level control of Fanuc systems

• Custom weld macros support via LS files

• Launch file and service definitions for easy orchestration

• Standalone API for non-ROS workflows via the Welder class

ROS Services

Provided by laser_run.py node:

Service Name	Type	Description
/weld_start	Weld.srv	Start arc welding process
/weld_end	Weld.srv	End arc welding process
/laser_arm	LaserArm.srv	Prepare laser for emission
/laser_disarm	LaserArm.srv	Disable laser safely
/laser_emit_start	LaserEmit.srv	Begin laser emission
/laser_emit_stop	LaserEmit.srv	Stop laser emission
/set_override	Trigger.srv	Set override to 100

All services return a bool State field indicating success.

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Welder Class

The welder class has the following methods that can be called using an instance directly, if you prefer to not use ROS Services

Method Name	Purpose	Description
laser_ready_arm	Prepare and arm laser	Sets laser power, performs safety/alarm checks, locks door, enables controls, waits for ready.
laser_start_emit	Start laser emission	Turns on laser emission (laser output).
laser_stop_emit	Stop laser emission	Turns off laser emission, pulses stop controls and resets sync inputs.
laser_disarm	Disarm laser safely	Disables external enable, system on, laser emission, pulses air knife and fume extraction before shutdown.
laser_error	Handle laser error	Prints error message and disarms laser safely (prevents recursive calls).
weld_start	Start arc welding	Checks for gas or wire faults, then starts weld and gas output if all clear.
weld_end	End arc welding	Sends command to end weld process.
gas_start	Start shielding gas flow	Checks for gas faults and enables gas flow output.
gas_end	Stop shielding gas flow	Stops gas flow output after a delay.
set_override	Set override to 100	Sets system variable OVERRIDE to 100 to enable welding and movement

Tutorials

• Tutorial 1 - DXF Trajectory Execution with Laser & Welding Integration
  • 1. Prerequisites
  • 2. Load and Parse the DXF File
  • 3. Center and Scale the Path
  • 4. Monitor Tool Pose and Trigger IO
  • 5. Initialize ROS Node and Services
  • 6. Setup Monitoring, Execute Trajectory
  • 7. Begin Motion Execution
  • Summary
• Tutorial 2 - ROS Welding Routine Explained
  • 1. Imports and Constants
  • 2. Fixed Parameters and Pose Definitions
  • 3. Main Execution Block
  • 4. Service Clients Setup
  • 5. Enabling welding
  • 6. Welding Routine
  • 7. Summary
• Tutorial 3 - Using the Welder Class Without ROS