Agriculture

Designing Bale Grab Attachment for Skid Steers

The client is one of Australia’s leading manufacturers of agricultural and earthmoving attachments. Their product lineup is built to unleash the full capabilities of Skid Steers, Tractor Loaders, Telehandlers, and Wheel Loaders. They also offer select products for Excavators and Mini Loaders.

Scope

The project involved the complete mechanical design of a custom bale grab attachment built to handle 1800mm diameter round bales. To ensure perfect compatibility, we also modified the skid steer loader interface to work seamlessly with the new attachment.

Our scope included:

Detailed mechanical design of the bale grab attachment and its integration with the skid steer.
3D CAD modeling of all parts and assemblies, covering both the attachment and interface areas.
Creation of clear 2D manufacturing drawings with tolerances, weld symbols, and GD&T where needed.
Bill of Materials (BOM) preparation and part number standardization to support smooth production and inventory management.
Hydraulic system integration, including cylinders, hoses, valves, and fittings — all laid out for compactness and ease of maintenance.

Challenge

Designing skid steer attachments involved several practical challenges that needed to be addressed to ensure reliable performance and easy manufacturing:

Synchronized Arm Motion: Ensuring both grab arms moved simultaneously using a mechanical equalizer to prevent bale slippage.
Compact Hydraulic Integration: Fitting the entire hydraulic system, into the compact space of the skid steer attachment. The 200 mm cylinder stroke length was a key design constraint that had to be factored in to ensure the grab arms moved effectively within this limited range.
Local Sourcing & Standards Compliance: Selecting materials and fasteners that complied with Australian Standards while being readily available in the domestic market.
Skid Steer Interface: Matching the attachment interface precisely with the skid steer mount for smooth operation.
Weight vs. Strength Balance: Balancing strength and weight to ensure the attachment was rugged enough for heavy use without overloading the skid steer or loader.

Solution

We began by understanding how bale grab attachments are used on skid steer loaders and other equipment in the field, especially in tough Australian farming and construction conditions. The client needed an efficient skid steer attachment that would be reliable, easy to service and simple to manufacture.

1. From Concept to Manufacturing-Ready Design

Our team handled the full product design process in-house. We began by reviewing the concept design provided by the client, aligning it with their performance goals and machine compatibility. From there, we moved into detailed design and 3D CAD modeling, making sure every part and assembly fit together smoothly.

We focused on adjusting the skid steer interface to ensure compatibility with the bale grab attachment, making it easy to integrate and handle bales with a 1800mm diameter.

Once the models of skid steer and bale grab attachment were finalized, we created precise 2D drawings with weld symbols, tolerances, and GD&T (as per ASME Y14.5) to ensure proper alignment. These clear drawings were easy for the client's team to follow.

We also provided a complete Bill of Materials (BOM) and standardized part numbers, simplifying procurement, reducing ordering confusion, and streamlining inventory management.

2. Hydraulic System Integration

A key part of the design was integrating the hydraulic system, including hoses, cylinders, valves and fittings, into a compact layout that allowed smooth movement. We followed ISO 18752 guidelines for hose routing and chose components for easy maintenance and durability.

The client required a 200 mm cylinder stroke length to ensure optimal arm movement. We incorporated this into the design while also adding a mechanical equalizer system to keep both grab arms in sync. This prevented bale slippage and provided stable handling, even at high speeds or on uneven terrain.

3. Material Selection and Compliance

We selected strong, locally available materials to keep manufacturing simple and durable:

⁃ Main structure and arms: Grade 250 mild steel ⁃ Hinge pins: AISI 1045 cold drawn steel for high strength ⁃ Fasteners: High-tensile bolts and Nylock nuts, compliant with AS/NZS 1252, AS 1111.1, and AS 1112.1

These choices made sure the attachment would be durable in the field and easy to build and repair with parts readily available in the Australian market.

4. Designed for Easy Fabrication and Assembly

We applied Design for Manufacturability (DFM) principles throughout the design. That meant using standard profiles, reducing weld complexity and making sure all parts could be assembled quickly without special tools. We also optimized the layout for field servicing, with accessible grease points and removable pins.

Bale grab skid steer attachment cad model

Value and Benefits

The skid steer attachment was designed to withstand tough Australian agricultural conditions, ensuring reliability and durability.

Customizing the skid steer design to sync with the bale grab attachment improved overall functionality and ensured seamless integration, resulting in better performance and less downtime in the field

Clear drawings, standardized parts and a simple Bill of Materials made the manufacturing process efficient.

Use of standard materials and components helped keep manufacturing costs low.

Ready-to-manufacture documentation allowed the client to move to fabrication and testing quickly.