How to Select a Heavy-Duty Manipulator for Foundry Handling

Material handling in a foundry is very different from conventional factory handling. Castings and workpieces may be heavy, hot, irregularly shaped and difficult to grip, while the handling operation may require lifting, rotating, tilting and accurate positioning.

For these applications, selecting a heavy-duty foundry manipulator is not simply a matter of matching workpiece weight to machine payload.

A reliable selection should consider the complete handling condition:

Load → Center of Gravity → Working Envelope → Required Motion → Gripper → Duty Cycle → Working Environment

This guide explains the main factors that should be evaluated when selecting a heavy-duty manipulator for foundry handling.

1. Start with the Workpiece

The first step is to define the workpiece to be handled.

Important information includes:

• Maximum and minimum weight

• Overall dimensions

• Workpiece geometry

• Material

• Gripping position

• Center of gravity

• Workpiece temperature

A drawing or 3D model is particularly useful for irregular castings.

The workpiece should always be evaluated together with the proposed gripping method. A compact 800 kg casting and a long, eccentric 800 kg casting can impose very different loads on the manipulator.

2. Payload Capacity Is Only the Starting Point

The RS Series includes three nominal payload classes:

However, machine selection should not be based on workpiece weight alone.

The complete load condition may include:

Workpiece + Gripper/Tooling + Load Position + Dynamic Effects

The position of the combined center of gravity is particularly important. As the load moves farther from the gripping or supporting point, the resulting moment on the manipulator changes.

Therefore, simply selecting the next payload class above the workpiece weight is not a complete engineering method.

The actual load case should be evaluated before the final model is confirmed.

3. Define the Required Working Envelope

The manipulator must be able to reach every required operating position.

For the RS Series:

Selection should be based on the actual movement path:

Pickup Position → Process Position → Discharge Position

A larger working radius is not automatically better.

The installation position should allow the manipulator to complete the required movement while avoiding unnecessary reach and interference with surrounding equipment.

For this reason, a basic plant layout showing the manipulator, workpiece positions and nearby equipment is highly useful during technical evaluation.

4. Define the Required Workpiece Motion

The next question is not simply how many axes the machine has, but:

What movements must the workpiece actually perform?

The RS Series uses a six-degree-of-freedom configuration. Depending on the application, the handling sequence may require the workpiece to be:

• Lifted and lowered

• Moved horizontally

• Rotated

• Tilted

• Reoriented

• Presented to another machine or workstation

This is particularly important for operations such as grinding, gate and riser removal, coating or other processes where the workpiece must be continuously repositioned.

The complete motion sequence should therefore be defined before the manipulator configuration is finalized.

5. Gripper Design Is Part of the Handling System

The gripper should not be treated as a secondary accessory.

It is the mechanical interface between the manipulator and the workpiece.

The available RS Series gripper opening ranges are:

However:

Gripper Opening ≠ Gripping Capability

The correct gripper depends on:

• Workpiece geometry

• Gripping location

• Surface condition

• Center of gravity

• Workpiece temperature

• Required rotation and orientation

Round castings, housings and irregular workpieces may require different gripping arrangements even when their dimensions and weights are similar.

For this reason, the workpiece drawing and intended gripping position are essential inputs when engineering the handling solution.

6. Evaluate Temperature and Foundry Environment

Foundry manipulators may operate around hot castings, furnaces, dust, scale and other demanding process conditions.

The customer should therefore provide both:

Workpiece temperature

and

Operating environment

These are not the same.

Handling a hot casting for a short period is different from operating continuously close to a furnace or another strong radiant heat source.

Depending on the application, thermal exposure may affect the gripper, hydraulic components, hoses, seals, electrical components and other machine elements.

Rather than describing an application simply as “high temperature,” the technical evaluation should define:

• Workpiece temperature

• Exposure duration

• Distance from the heat source

• Ambient conditions

This allows appropriate protection measures to be considered during engineering.

7. Consider the Production Cycle

The manipulator must also match the required production rhythm.

Useful information includes:

• Pieces handled per hour

• Handling time per workpiece

• Number of shifts

• Required movement sequence

• Time spent holding or positioning the workpiece

The same payload and working envelope can result in different equipment requirements when the machine operates occasionally versus continuously over multiple shifts.

The handling cycle should therefore be considered together with the mechanical load.

8. Evaluate the Complete Process and Layout

A foundry manipulator normally operates as part of a process rather than as an isolated machine.

Typical applications may include:

• Hot workpiece handling

• Loading and unloading

• Gate and riser removal

• Grinding and finishing

• Coating operations

• Workpiece transfer and positioning

The layout should show where the workpiece starts, where it must go, surrounding equipment and available installation space.

This allows the engineering review to consider:

Reach + Motion Path + Equipment Interference + Operator Access + Maintenance Space

The manipulator can then be positioned according to the actual process rather than simply according to its maximum working radius.

9. Information Required for Manipulator Selection

For an initial technical evaluation, provide:

Photos or videos of the existing operation are also useful, particularly when replacing manual handling or integrating the manipulator into an existing production line.

Selecting the Manipulator as a Complete Handling System

A heavy-duty foundry manipulator should be selected as a complete handling system rather than by payload alone.

A practical selection sequence is:

Workpiece
→ Load & Center of Gravity
→ Working Envelope
→ Required Motion
→ Gripper
→ Production Cycle
→ Temperature & Environment
→ Manipulator Configuration

The objective is not simply to select a machine capable of lifting the workpiece.

The manipulator, gripper and working envelope must work together to safely handle and position the workpiece throughout the required production process.

Need Help Selecting a Foundry Manipulator?

WELTOP NEXA evaluates foundry handling applications according to the actual workpiece and production process.

For an initial evaluation, send us your:

Workpiece Drawing + Weight + Dimensions + Temperature + Required Handling Operation + Basic Workshop Layout

We can then evaluate the appropriate RS model, working envelope and gripper configuration for your application.