Safety Related to CNC Work

On the walls of many machine shops may hang a safety poster with a simple, yet very powerful message:

The first rule of safety is to follow all safety rules

Safety is Something Related to Machining?

The heading of this article does not indicate whether safety is oriented at the programming or the machining level. There is no reason for it – safety is totally independent. It stands on its own and it governs behavior and activities of everybody in machine shop and outside of it. At first sight, it may appear that safety is something related to machining and machine operations, perhaps to the machine setup as well. That is definitely true but hardly presents a complete picture.
Safety is the most important element in programming, setup, machining, tooling, fixturing, inspection, shipping, and you-name-it operation within a typical machine shop daily work. Safety should never be compromised and cannot be overemphasized. Companies talk about safety, conduct safety meetings, display posters, make speeches, call experts. This mass of information and instructions is presented to all of us for some very good reasons.Quite a few are based on past tragic occurrences -many laws, rules and regulations have been written as a result of inquests and inquiries into serious accidents.

Automation is really help to Safety?

At first sight, it may seem that in CNC work, safety is a secondary issue, not as important as in manual machining. There is a lot of automation in CNC, a part program that is used over and over again, tooling that has been used in the past, a simple setup, etc. All this can lead to complacency and false assumption that safety is taken care of. This is a wrong view that can have serious consequences.
Safety is quite a large subject but a few points that relate to CNC environment are very important. Every machinist should know the hazards of mechanical and electrical devices. The first step towards a safe work place is with a clean work area, where no chips, oil spills and other debris are allowed to accumulate on the floor. Taking care of personal safety is equally important. Loose clothing, jewelry, ties, scarfs, unprotected long hair, improper use of gloves and similar infractions, is dangerous in any machining environment. Protection of one’s eyes, ears, hands and feet is strongly recommended.

Devices at around

While a machine is operating, protective devices should be in place and no moving parts should be exposed. Special care should be taken around rotating spindles and automatic tool changers. Other devices that could pose a hazard are pallet changers, chip conveyors, high voltage areas, hoists, etc. Disconnecting any interlocks or other safety features is dangerous – and also illegal, without appropriate skills and authorization.

More axes, more attention!

Modern technology has brought machines that may have nine or more axes, tight work areas, special tool indexing, part transfers, etc. While these features dramatically increase company productivity, they also require additional safety training – and practicing all safety rules.
In CNC programming (manual or computer based), observation of safety rules is equally important. A tool motion can be programmed in many ways. Speeds and feeds have to be realistic, not just mathematically ‘correct’. Depth of cut, width of cut, various tool characteristics, they all have a profound effect on overall safety in the shop.
All these ideas are just a very short summary and a reminder that safety should be taken seriously at all times.