When you stop to think about it, your cutting tools are getting absolutely put through the ringer. They are subjected to:

• High localised stress at the edge of the tool
• High temperatures along the rake face
• Sliding chips along the rake face
• Sliding of the tool along the newly machined workpiece

All of this without coolants and sometimes continuously for hours on end. All of this heat causes the immediate edge of the cutter to reach 550-750 degrees Celsius! Not to mention the sheer amount of force placed on the cutter by the spindle and chip flow.

All of this heat is essentially melting away the cobalt (and titanium) light alloys which bond the wolfram particles of the carbide together within the rod. This begins to occur at temperatures as low as 300C.
In other words: the glue holding the rod together is being slowly melted

Now don’t get me wrong, the titanium carbide (Ti-C) that we use in our rods can withstand a bucketload of heat. But, just like a bloke in the shed over summer in QLD, if you let them cook for long enough they will start to get a bit rough around the edges.

Here is where coatings come in. Coatings have the following benefits:

• Lower friction
• Higher resistance to heat
• Higher resistance to impact
• Diffusion barrier between the tool and the chip

The DLC (Diamond-like Carbon) coating used on our aluminium cutters can

withstand 350-450C and the nano-tech coating used in our Xtreme Blue cutters can withstand up to 1200C. Just picture the bloke in the hot shed getting an aircon, fans, a cold wet towel and an ice-cold beer. This is what a coating is to your cutter.

However, this is only the heat resistant side of things. Coatings also increase the hardness of the cutter substantially (up to 4200HV), absorb and disperse impact and reduce cutting friction.

By this point I bet you are thinking: “Coatings sound awesome, but if they are so great, why doesn’t everyone use coatings?”

Coatings are great, but they increase the thickness and radius of the cutting edge on your tools. Just as on a worn cutter, the once sharp edge will be rounded and dull. Putting a thick coating on a new sharp cutter essentially dulls the edge. This will result in a worse finish and more stress on the cutter, which defeats the purpose entirely.

This is the exciting part of nano-tech coating, innovative coating application technology allows the special titanium coating to be applied at a thickness of 0.0008-0.001mm. This is less than half the thickness of more common coatings, such as DLC (>0.002mm).

Therefore, cutting tools with nano-tech coatings have all the longevity benefits of coating, with no reduction in the machined finish or increased stress on the cutter. In summary nano-coated cutters have:

• Increased resistance to heat and impact
• Increased hardness
• Same sharp edge as uncoated bits

This is what allows Xtreme Blue cutters to cut two times as many boards as regular uncoated cutters.

For the people working with CNC machines day-to-day; life B.C. (before CNC) seems like a distant memory. You never forget your first, nor, the process of choosing and installing it. It’s an exercise in patience, fast-paced learning and sometimes saying to yourself, “I wish I knew this 6 months ago..”

Don’t be too hard on yourself, “Those who never made a mistake never tried anything new.” Nonetheless, a question I always like to ask the manufacturers I visit is, “What are the most important things you wish you knew before purchasing your first CNC?”

Here are the top 5 responses:

1. Get the right software for you! Software can be more important than the machine!

The software is the brains of the machine. Sometime referred to as “digital tooling” the software creates a link between the hardware you are using and what you are trying to produce. Software includes CAD and CAM programs, code editors, part optimising programs, and feed speed, chatter and spindle load calculators. Without trying to set off the stomach of a nauseous technophobe, all of this “digital tooling” should be given as much thought and consideration as the physical hardware of the machine.

2. Don’t buy too much machine!

You don’t want your machine overloaded and working all the time, but an idle machine is still costing you money. Consider the bottlenecks within your operation before and after the machine is installed. E.g. The biggest and fastest CNC won’t speed up your output if you have the smallest and slowest edge bander. Always consider the bigger picture and what other investments are required to realise the potential of this one!

3. Think about what you currently produce, but more importantly what you would like to produce if you had the equipment.

CNC machines are some of the most versatile machines on the planet. They can machine many different materials and create complex parts. What will you use yours for? Often the solution can come from a tooling integration. Many operators would be surprised to find out the true capability of their machine with a few different tools. Consider what is done in-house, outsourced and if there any special processes required.

4. Plan how you will service and maintain the machine!

Aim to keep your machine clean and well-greased and understand the limits of the motors and bearings. Ask the machine supplier what needs to be done to minimise the risk of breakdown.

5. Get advice on the initial tooling you need and get them to explain the best machining processes and parameters for the tools.

Relating to point 1 and 3, the tooling selection will affect what you produce and how you produce it on your CNC machine. Tooling is material and application-specific. Similarly, to point 2, don’t buy too much tooling. Standardise and consolidate where possible to minimise operational cost and machine time. Tooling is an ongoing investment in the quality of the products you manufacture!