CNC MACHINES AND SAFETY
CNC machines are very safe to use as they are designed to be as safe as possible. One of the main advantages of CNC machines is that they are much safer than manually operated machines. The animation below shows a Boxford A3 HSRi² CNC Router with many of its safety features labelled.
1. Most modern CNC machines are designed so that the cutting tool will not start unless the guard is in position. Also, the best CNC machines automatically lock the guard in position whilst the cutter is shaping material. The guard can only be opened if the cutter has stopped.
2. It is essential that pupils / students / machine operators receive ‘quality’ instruction before attempting to use any CNC equipment.
3. CNC routers, used for shaping materials such as woods and plastics, have built in extraction. Dust can be very dangerous if inhaled and can also cause eye irritation. The CNC Router shown above has an outlet for an extraction unit. As the router is fully enclosed, dust cannot escape into the atmosphere. If an extraction unit is attached the dust is removed automatically. Most manually operated machine routers have very limited extraction systems which leave some dust in the air.
4. The CNC router above has a single phase electrical supply. Most older machines such as manually operated milling machines and centre lathes have three phase supplies. A single phase electrical supply can be ‘plugged’ into any available socket. The electrical supply for the machine comes through a residual circuit breaker (RCB). If an electrical fault develops the RCB will cut off electrical power immediately.
5. Single phase CNC machines can be moved more easily because they are simply unplugged and relocated. Three phase machines are specially wired by an electrician into the electrical supply and cannot be unplugged.
6. Most CNC machines work behind a guard or even a closed, transparent safety door. This means that the operated cannot be hurt by ‘flying’ pieces of sharp/hot material.
7. Commonsense applies to the use of all machines including CNC machines. Basic safety training regarding working in a workshop and with other machines applies to CNC machines as well.