15 Mar Protecting your Workforce: Safety Considerations for CNC Machinists
CNC machinists are professional, highly qualified personnel who require safe workplaces in which to carry out their duties. Companies have both a legal and moral obligation to provide this. Not only is this a mandatory requirement, but creating the safest working area has a direct impact on productivity.
The following looks at essential safety issues that benefit every aspect of a manufacturing operation.
Robust Safety is the Key to Optimal Productivity
The three golden rules of safety are based around G-code programmes. They must:
- Ensure that all operators are working in a secure environment.
- Ensure that all devices, cutting and machine tools are in optimal condition
- Must be operated within manufacturer parameters
And, naturally, the components produced must be of a good standard with a minimal tolerance for error. This combination will deliver the lowest operational costs while keeping workers safe from injury.
Adhering to these rules can be done by:
- Using bar feeders or bar pullers
- Keeping machining pressures within safe operating limits.
- Using the correct hand of tooling
- Using clamps for powerful machine operations
- Taking control of the rapid approach movement
Using bar feeders or bar pullers
Bar feeders are commonly used to machine multiple workpieces – CNC lathes are a good example. Ensuring that the bar is completely enclosed within the feeder means its length is fully supported throughout the machining process. A failure to do this and allowing even a small part of the bar to protrude from the spindle will mean that, as the turning process accelerates, the risk of the unsupported element shearing away is extremely high. Even if it doesn’t detach completely, it will damage the equipment. A breakaway piece of bar thrown into the factory becomes, quite literally a missile, and can cause severe injury or even death.
When bar feeders are not an option, then a bar puller should be used in its place. This is a tool fitted in the turret that provides constant pressure to pull the bar in the right direction as it feeds into the machine.
Keeping machining pressures within safe operating limits
Aggressive cutting condition without adequate support creates unsafe machine dynamics. It’s essential that the operating limits of the machine and/or workholding device are sufficient to cope with the required programming needs.
Use the correct hand of tooling
For high-energy applications, such as facing, turning and rough boring, you should use the hand of tooling that best absorbs the forces at play. Not doing so will cause play in the way systems, leading to maintenance issues, such as sizing problems and chatter.
Use clamps for powerful machine operations
In a similar vein, clamps should be utilised for powerful operations. Without them (or if they aren’t correctly engaged) the forces will be absorbed by other machine elements, such as the drive motor and gears. This leads to reduced MTBF, increasing both the running costs and the likelihood of producing inaccurate parts.
Take control of the rapid approach movement
The first cut of a new program is always the highest risk. It’s essential that CNC machinists know how to take control of this rapid approach moment. While most programmers use a distance or around 2.5mm, some work to even tighter parameters.
It’s good practice to use consistent setup protocols. This means that both machinists and programmers follow the same blueprint, and everyone is aware of how the machine will approach. Operators and set up personnel should be fully aware of how to make the machine crawl during the first approach to the work surface, be this though a dry run, feed hold, single block or rapid override.
Workplace safety is a dynamic subject. All users should follow strict regulations that include mandatory daily equipment checks and the use of the correct PPE. Regular health and safety assessments should be carried out and, when identified, new procedures should immediately be implemented into everyday practice.
Both employer and employees should work together to ensure a safe workplace and optimal output. This ensures the company remains competitive, viable and provides sustainable employment for its workers for many years to come.