What Is a WAAM Compact System and How Does It Work?

A WAAM Compact System converts a digital component design into a near-net-shape metal part through coordinated robotic deposition.

The production workflow can be divided into several stages.

1. The component is designed digitally

The process begins with a three-dimensional CAD model.

Engineers assess whether the component is technically and commercially suitable for WAAM. Strong candidates often include large metal parts that would otherwise require extensive machining, fabrication, casting tooling, or multi-part assembly.

The design may be modified to account for:

• Deposition direction
• Layer height
• Bead width
• Robot accessibility
• Positioner movement
• Thermal distortion
• Machining allowance
• Support or fixture requirements
• Start and stop locations
• Part orientation

The final CAD geometry is converted into deposition paths using offline programming or additive manufacturing software.

2. The deposition path is programmed

The robot needs more information than the external shape of the part. It requires a controlled path that defines how each layer will be deposited.

The programming stage establishes:

• Robot trajectory
• Torch orientation
• Travel speed
• Layer sequence
• Positioner movement
• Wire feed rate
• Deposition start and stop commands
• Interpass waiting periods
• Process parameter changes

MetalWorm Offline Programme is available in both the Standard and Advanced system configurations.

Offline programming allows engineers to prepare and evaluate robot paths digitally rather than teaching the entire component manually inside the cell. This can reduce programming effort and improve repeatability for complex or multi-axis builds.

3. Metal wire is continuously supplied

Wire Arc Additive Manufacturing uses metallic wire as the feedstock.

During production, the wire is fed continuously toward the deposition zone. Depending on the selected power source and material, the system can work with an appropriate MIG, MAG, TIG, plasma, or laser-based configuration.

Only one power-source type is selected for a particular system configuration.

The material must be compatible with the deposition process and the performance requirements of the finished component. Depending on application development and process qualification, WAAM may be used with weldable materials such as steels, stainless steels, aluminium alloys, titanium alloys, nickel-based alloys, and other engineering metals.

4. The heat source melts the wire

The selected energy source melts the incoming wire and creates a controlled molten pool.

In arc-based configurations, electrical parameters and wire-feed behaviour determine how the material is transferred into the melt pool.

Important process variables include:

• Current
• Voltage
• Wire feed speed
• Robot travel speed
• Gas flow
• Torch angle
• Contact-tip distance
• Layer height
• Interpass temperature

The interaction of these parameters determines bead width, bead height, penetration, deposition stability, thermal input, and surface condition.

5. The robot deposits each layer

The industrial robot moves the deposition torch along the programmed trajectory.

As the wire melts, material is deposited onto a substrate or onto the previously completed layer. The molten bead cools and bonds metallurgically with the material below it.

The sequence is repeated:

1. Wire enters the deposition zone.
2. The energy source melts the wire.
3. The robot follows the programmed path.
4. A metal bead is deposited.
5. The layer solidifies.
6. The robot or positioner changes orientation.
7. The next layer is added.

This controlled repetition creates a three-dimensional near-net-shape component.

6. The positioner controls part orientation

The positioner is a critical part of the Compact System.

A six-axis robot provides substantial movement freedom, but the positioner adds external axes that allow the workpiece to rotate or tilt. This helps keep the deposition torch at a suitable angle and gives the robot access to different surfaces.

Depending on the model, MetalWorm Compact Systems can include:

• A two-axis positioner
• A two-station rotary positioner
• A Double Skyhook positioner
• A THDZ positioner

The combined robot and positioner axes influence the types of geometries that can be produced.

Multi-axis movement can also help engineers avoid limiting every component to simple vertical wall deposition. The workpiece can be repositioned to support more controlled deposition on curved, angled, or otherwise difficult-to-access surfaces.

7. The process is monitored during operation

WAAM involves repeated heating, melting, deposition, and cooling. Process conditions can therefore change as the component grows.

MetalWorm Compact Systems are designed to control and monitor production events during operation. The available level of monitoring depends on whether the Standard or Advanced configuration is selected.

Process monitoring may involve data such as:

• Temperature
• Torch-to-part distance
• Gas flow
• Humidity
• Oxygen level
• Bead or layer appearance
• Welding current and voltage
• Sound signatures
• Thermal behaviour
• Three-dimensional surface condition

This information can help operators detect deviations before they affect a substantial portion of the build.

8. The near-net-shape part is finished

A WAAM Compact System normally creates a near-net-shape component rather than a fully finished precision part.

The deposited geometry may therefore require:

• CNC machining
• Heat treatment
• Stress relief
• Surface finishing
• Dimensional inspection
• Non-destructive testing
• Mechanical testing
• Metallurgical evaluation

Machining allowance should be included during design and toolpath planning. Critical interfaces, holes, sealing faces, bearing surfaces, and tight-tolerance features are commonly completed after deposition.