Log Grapple Guide: From Basics to Selection & Installation
1. What is a Log Grapple? How does it work?
A log grapple is a special attachment installed on construction machinery such as excavators and cranes to grab and carry round materials such as logs.
A typical log grapple consists of an inner grab arm, an outer grab arm, a bracket, a synchronous connecting rod, a hydraulic cylinder, and a rotating body. The inner and outer grab arms are connected to the bracket’s hinge axis. The synchronous connecting rod is connected to the inner grab arm’s hinge axis at one end and to the outer grab arm’s hinge axis at the other. The hydraulic cylinder drives the grab arm’s opening and closing, and the rotating body enables 360-degree rotation of the grab.
Working Principle: The hydraulic system provides power for the log grapple. One hydraulic oil line controls the cycloid motor in the rotating body, achieving the directional rotation of the grab. Another hydraulic oil line controls the extension and retraction of the hydraulic cylinder, which in turn drives the closing and opening of the inner and outer grab arms. The synchronous connecting rod ensures that the inner and outer grab arms work synchronously, thus realizing the grabbing and unloading of logs.
2. What are the advantages of a Log Grapple?
High Safety: Some log grabs are equipped with a hydraulic cylinder safety check valve. Even if the hydraulic system fails or suddenly stops, it automatically locks the gripped material to prevent it from falling, reducing safety risks.
Durability: The main structure is mostly made of high-strength, wear-resistant steel, such as NM400 steel. Key stress points undergo a gradient hardening treatment for excellent wear resistance and long-term use in harsh environments.
Flexible Operation: The log grapple features a rotation function, allowing the operator to control the rotation speed and achieve 360-degree clockwise or counterclockwise rotation.
Wide Compatibility: A variety of models are available to match excavators of different tonnages, from small 1-3 ton excavators to large 17-24 ton excavators.
3. What are the application areas of a Log Grapple?
Forestry: Used for loading, unloading, stacking, and transporting logs at forestry farms, lumber processing plants, and other locations. It can also be used to clear branches and stumps after felling.
Construction and Demolition: Used to clear trees, shrubs, and roots at construction sites to prepare the site, and to grab and move waste wood during demolition operations.
Landscaping: Used for moving and planting large trees and landscaping rocks, as well as clearing dead branches and leaves in gardens.
Agriculture: Used for moving lumber, installing fence posts, and handling wood chips and shavings for biomass energy production.
4. How to select a Log Grapple?
Excavator Compatibility: Select the appropriate log grapple based on the excavator’s tonnage and hydraulic system specifications to ensure proper installation and operation.
Grasping Capacity: Consider the log grapple maximum gripping weight and the gripper’s opening and closing dimensions to meet the demands of handling logs of varying diameters and weights.
Material and Quality: Choose a log grapple made of high-strength, wear-resistant materials, featuring a sturdy structure and high-quality welding to ensure durability and reliability.
| Model | Unit | RLG1000 | RLG1200 | RLG1400 | RLG1700 | RLG2000 |
|---|---|---|---|---|---|---|
| Excavator weight | Ton | 1-3 | 1-5 | 5-7 | 12-16 | 17-24 |
| Lbs/Pounds | 2000 – 6000 | 2000 – 10000 | 10000 – 14000 | 24000 – 32000 | 34000 – 48000 | |
| Weight (Without motor) | Kg | 69 | 82 | 139 | 260 | 365 |
| Lbs/Pounds | 152 | 181 | 306 | 573 | 805 | |
| Weight (With motor) | Kg | 89 | 107 | 169 | 312 | 435 |
| Lbs/Pounds | 196 | 236 | 373 | 688 | 959 | |
| Working pressure | Bar | 210 | 210 | 210 | 210 | 210 |
| Max load | Kg | 1500 | 2000 | 2000 | 3000 | 5000 |
| Lbs/Pounds | 3307 | 4409 | 4409 | 6614 | 11023 | |
| Max clamp power | KN | 9.5 | 12 | 14 | 17 | 21 |
| Materia | Material | NM400 | NM400 | NM400 | NM400 | NM400 |
| Rotation motor | Model | 30F | 40F | 50F | 60F | 100F |
| Oil hose | inch | 3/8 | 3/8 | 3/8 | 1/2 | 1/2 |
