Adding Secondary Bevel: A Key Step to Enhance Laser Cutting Efficiency and Quality

Introduction

In the field of laser cutting, the pursuit of higher efficiency, better quality, and lower cost never stops. In the past, we focused on increasing laser power and cutting speed. However, many companies find that even with the fastest cutting machines, they are still plagued by stubborn pain points: difficulty in utilizing remnant materials, loss of control during the cutting process, and the need for extensive manual grinding before welding.

These problems cannot be solved by a single piece of equipment; they require a systematic solution covering the entire process from "pre-positioning - mid-process monitoring - post-finishing". Today, we will delve into how the intelligent closed-loop system, composed of the secondary bevel device, BOCHU's "Sky Eye" system, and the BCW400F-E contour scanner, initiates an efficiency revolution in laser cutting.

Limitations of Traditional Secondary Bevel Solutions

Before the advent of laser secondary bevel solutions, the industry primarily relied on the following methods:

1. Semi-Automatic Flame Beveling (Commonly known as "Little Turtle")

Advantages: Simple structure, low cost, easy to use.

Disadvantages: Relies on manual marking for positioning, poor accuracy, slow speed, unstable cutting quality for arcs and corners, completely dependent on operator experience.

2. Robotic Workstation

Advantages: Possesses a certain degree of automation and flexible processing capability.

Disadvantages: Limited processing area (approx. 1.5m×1.5m) due to robot arm span; based on flame or plasma, cutting accuracy is poor (>2mm) and speed is slow; path planning for complex graphics has a high threshold, and operating costs are high with strong material dependency.

The core issue is: Traditional solutions lack effective positioning and deformation compensation mechanisms. When deviation occurs, manual intervention is necessary, making it difficult to guarantee processing consistency and efficiency.

The Precise Empowerment in the Early Stage by Scanner and Sky Eye

Before the secondary bevel can play its role, preparatory work is crucial. This relies on two "vanguards".

1. BCW400F-E Contour Scanner: From "Blind Cutting" to "Visible", Maximizing Material Value

Core Function: It is a vision sensor based on line laser technology, specifically designed for cutting systems. Its core mission is to replace the human eye and calipers, performing non-contact high-speed scanning of plates (especially irregular remnants) to obtain high-precision data on contour, hole positions, marks, etc., with accuracy up to 0.005mm.

Application Value:

1. Remnant Rebirth: Faced with irregular remnants, traditional programming is helpless. The scanner can quickly obtain their digital contour, and the software performs intelligent nesting to fit new parts within it. Subsequently, the secondary bevel function can precisely follow the path generated by the scan to perform high-quality processing on these reused parts, maximizing their value and saving material to the extreme.
2. Precise Alignment: For workpieces requiring secondary finishing (like beveling) based on existing holes or marks, the scanner can automatically identify datum features and calibrate the cutting path, ensuring the coaxiality and smooth transition of the bevel with the original structure, with errors controllable within 0.02mm.

2. Sky Eye System (Intelligent Remnant Kit): The "First Safety Net" of the Process

Core Function: Sky Eye is a high-end vision solution integrating industrial cameras, optical lenses, and intelligent algorithms. It performs rapid scanning and rough positioning of parts formed by straight cutting before secondary processing.

Application Value: Before secondary beveling starts, it confirms whether the part's position matches the theoretical programming. This avoids serious waste such as beveling the wrong edge or opening the bevel in the wrong position due to plate movement or deviations from the previous process, providing crucial initial accuracy assurance for the high-value finishing process.

The Art of Precision Machining with Secondary Bevel

1. The Essence of Secondary Bevel

Secondary bevel is not simply repetitive cutting, but an independent finishing process. It performs three-dimensional fine machining on the edge after the first cut by precisely controlling the cutting head's angle, power, speed, and gas pressure.

2. Three Core Values

Value One: Defect Correction, Achieving Perfect Edges

Technical Details: The first cut on thick plates easily produces dross, burrs, and perpendicularity deviation (taper). Secondary bevel employs a strategy of low power, high speed, and multi-pass scanning to "micro-carve" the edge, effectively reducing edge roughness (Ra value) from >12.5μm to 1.6-3.2μm, while correcting the taper to obtain a uniformly vertical cut surface.

Application Scenario: Directly meets the stringent requirements for edge quality in precision mechanical parts, hydraulic valve blocks, high-end instruments, etc., eliminating subsequent processes like milling and grinding.

Value Two: The Ultimate Solution for Welding Pretreatment

Technical Details: Can program and machine V-grooves, U-grooves, double J-grooves, etc., at any angle according to welding process requirements, with angle error controllable within ±0.5°, and root face height controllable. This provides an extremely consistent interface for welding.

Application Scenario: Applicable to all fields requiring high-quality welding, such as construction machinery, pressure vessels, and rail transit. Neat bevels can reduce weld gaps, improve penetration consistency, fundamentally eliminate hidden dangers like lack of fusion and incomplete penetration, and significantly enhance structural strength and safety performance.

Value Three: Overcoming the "Final Challenge" of Thick Plate Cutting

Technical Details: Addressing the issue where the first cut on plates over 20mm might fail to cut through completely at the bottom ("incomplete cut"), the secondary bevel can perform back gouging cuts, using specialized parameters to precisely remove the bottom connection points, ensuring complete separation and avoiding plate thermal deformation caused by excessive energy input in a single step.

Real-time Monitoring and Closed-Loop Error Correction by the Sky Eye System

Uncertainty during processing is another major enemy of quality. The Sky Eye system plays the role of "guardian" in the mid-process stage.

Real-time Quality Monitoring: During the secondary beveling process, the Sky Eye system continuously monitors the cutting area. It can intelligently identify abnormal situations such as "beam break", "nozzle clogging", and "focus lens contamination", immediately stopping the machine and issuing an alarm to prevent batch scrap and protect the expensive bevel cutting head.

Dynamic Error Compensation: Plates can shift during processing due to "fixture loosening" or "thermal deformation", causing deviation between the actual path and the theoretical path. The Sky Eye system can compare the two in real-time, automatically calculate the deviation value (X/Y/Z axes), feed it back to the control system to dynamically adjust the cutting head position, achieving real-time closed-loop compensation and ensuring the final workpiece's dimensional tolerance remains stable within ±0.03mm. This is crucial for processing large workpieces several meters long.

Data Storage and Traceability: The system can automatically store cutting images, parameters (power, speed), and deviation data for each batch of workpieces, forming a "processing record". If defects are found later, data can be reviewed to locate the problem (e.g., a batch deviation originated from plate thermal deformation), facilitating process optimization and meeting the "full-process traceability" requirements of industries such as aerospace and medical devices.

The Intelligent Production Closed-Loop: 1+1+1 > 3

The combination of the three does not merely stack functions but constitutes a highly intelligent production closed-loop:

• Early Stage (Scanner): "Scanning & Positioning" – Solves the problem of "Where is the material?", providing a precise machining datum for secondary beveling and maximizing material utilization.
• Mid-Stage (Sky Eye): "Monitoring & Correction" – Solves the problem of "Is the process stable?", ensuring the reliability of the secondary beveling process and consistent quality.
• Late Stage (Secondary Bevel): "Precision Machining" – Solves the problem of "Is the edge acceptable?", ultimately outputting high-value, ready-to-use perfect workpieces.

Final Benefit: This system can significantly reduce the scrap rate from 5% to below 1%, increase single-batch production capacity by 20%-30%, and completely eliminate the grinding process before welding, achieving true "unmanned" finishing.

Video and sample display：

The Added Advantages of BOCHU's Secondary Bevel Solution

BOCHU's secondary bevel solution is not a simple replacement for traditional processes but a comprehensive upgrade in material utilization, process adjustment, processing capability, speed & precision, cost, and flexibility.

1. More Material Saving

Disadvantage of Single-Step Beveling: When beveling directly on a full plate, space must be reserved between parts for the bevel cut path, resulting in significant plate waste.

Improvement with Secondary Bevel: First, perform a straight-cut initial blanking, allowing parts to be maximally common-edge cut. Then, perform the bevel finishing.

Image description: One-time cutting and common edge

Actual Effect: Compared to single-step beveling, secondary beveling can significantly reduce the waste area, increasing material utilization by 5%–10%, which is particularly significant for large-format thick plate production.

2. Easier Process Adjustment

Take processing a K-type bevel on 30mm carbon steel plate as an example (both upper and lower bevel angles are 45°, heights are 10mm, root face 10mm):

Single-Step Beveling: The actual bevel cutting thickness reaches 42.4mm, requiring high cutting energy; dross is hard slag, difficult to clean.

Secondary Beveling: Only needs to cut a thickness of 14.1mm, cutting energy requirement is reduced by two-thirds; dross is soft slag, easier to handle.

Effect Difference: Secondary beveling has faster cutting speed, smaller heat-affected zone, significantly improved cut surface quality, and better subsequent welding consistency.

3. Stronger Processing Capability

The processing capability of traditional single-step beveling is limited by laser power, while secondary beveling breaks through this bottleneck by optimizing process decomposition: