As manufacturers struggle to overcome an apparent skills shortage, material removal is rapidly growing application area of robotics. Once constrained to a few specialist tasks due to limitations in force sensing and machine vision, today’s manufacturing environment sees a broad range of applications, from trimming flashing from plastic and aluminum moldings, removing moulding flash and edging material from carbon fiber products, polishing molds and dies and deburring edges following machining.

While previously these applications relied solely on compliant tools, more recent developments such as force sensing control and vision have created the ability to handle variability in the position and size of the material that has to be removed. Force sensing provides greater control over cutting loads and the direction of the applied force, leading to more consistent and cleaner edges. In more recent times, the robot is used to articulate the part itself over the tool, versus the traditional method of a robot mounted tool. Whichever approach is used, the accuracy and path repeatability of the robot provides less variability across the substrate, irrespective of the die or machine they were manufactured in, overcoming one of the major hurdles for manufacturers – rejected parts due to inaccuracy and a lack of consistency. By applying the appropriate amount of pressure between the part and the material removal equipment, precise results can be achieved in every cycle.

This robot is fitted with a force torque sensor. It is mounted between the frame of the end of arm tooling and the spindle so that the robot can “feel” the loads during trimming and deburring. The spindle has a tool change function which allows it to change between a range of tools using BT30 tool changers.

Benefits

The most obvious advantage of robotic material removal solutions is the superior repeatability when compared to traditional means, however there are several other key advantages and flow on effects that need to be considered when evaluating the benefits of a system:

Accuracy and Consistency

Accuracy and consistency in an automated material removal system results in a significant reduction in reject parts. The flow on effect is a reduction in quality related concerns, such as rework, scrap, or warranty concerns.

Typically, when a customer finds a part that doesn’t meet the tolerance, they will return the entire batch, so it is critical that these are reduced or eliminated at the point source of origin.

The adoption of robotic vision provides real time error proofing to ensure proper process and product quality.

Improvements in throughput, or speed

A correctly programmed vision and force sensing material removal system can reduce the production time significantly. A recent case study by ASA found that throughput was able to be increased by 50% over traditional manual operation.

Tool wear

The expense related with tooling consumables means that the tools wear at a much lower and more predicable rate, so the preventative maintenance costs associated in maintaining these items is further reduced.

Exposure to hazardous environments

Removing people from the process facilitates a reduction in exposure to harmful fumes, dust, and repetitive tasks that can often lead to repetitive strain injuries such as carpal tunnel syndrome and vibrating white finger. At the same time, reducing human exposure also reduces the annual expense of Personal Protective Equipment (PPE) in the form of protective eyewear and earmuffs.

Labour costs

A further flow on effect of the higher consistency part-to-part is a reduced requirement for manual inspection labor.

The recent technological advancements in robotics have created a much more diverse application range for material removal.

While the applications for automated material removal have grown, the benefits of implementing a system are sound and proven. Precise results resulting in less scrap and a reduction of waste at the point source of origin, improved throughput, a reduction in consumables, reduced exposure for personnel to potentially hazardous working environments, and a reduction in the labor requirements for manual inspection.

These considerations need to be carefully balanced against a business case for automating your material removal process to determine the total annualized rate of return on the equipment. Given economies of scale, the question must be asked – will you innovate, or evaporate?