Mastering 5-Axis CNC Tool Grinders: A Comprehensive Guide

The Basis

A 5-axis CNC grinding machine is a cutter grinder that is typically used to form and sharpen the milling cutters as well as other sorts of tool bits. Employing a series of grinding tools, 5-axis CNC tool grinders can provide a wide variety of different grinding operations. For example, surface grinding, cylindrical grinding, or complex shape forming. 5-axis CNC grinding machines are becoming increasingly popular due to the high precision and complex operations with the CNC systems they offer. 

The term CNC is the abbreviation for Computer Numerical Control, 5-axis CNC grinding machines rely on computerized controls to manipulate the cutting tools in order to grind the stock materials. In CNC machining, the procedures include designing the model and converting the CAD files to the computer program, then preparing and executing the CNC operations in the CNC grinding machines. To fully manage the skills of controlling and monitoring the CNC grinding process, the operators need to understand the relationship between the workpiece and the grinding wheel as well as the tool geometry of the 5-axis CNC grinding machine. 

As the name implies, the 5-axis tool grinder can provide multiple working axes and planes for a huge variety of complex machining. The table which is utilized in the large 5-axis CNC grinding machine can move longitudinally and laterally, and the machine vise can swivel in multiple planes. In addition, the flexibility in the machining cutters can achieve not only a huge variety of usage but also the critical clearance angles during 5-axis grinding.

The Structure in a 5-axis CNC Tool Grinder

As mentioned, the 5-axis structure can provide ideal productivity, high accuracy as well as unlimited flexibility for the 5-axis CNC grinding machines. To achieve the 5-axis machining, the 5th axis table is an ideal accessory that can be mounted in order to obtain multiple face machining capabilities. 

In original automatic grinding machines, there might be only X-axis, Y-axis, and Z-axis that are the linear operational axes to operate along the same plane. Adding with the 4th and 5th axis, which are actually 180 rotational axes, work around the linear axes can upgrade the grinding machine to manufacture intricate shapes in a short amount of time. Using the indexing table can add two rotational directions to the original three linear cutting directions, and the auxiliary slides can be used for fixturing the metal parts being ground or improving the guidance of grinding wheels across the tooling area. The tool guidance, part support, and tailstock are the common elements that can be accommodated on the auxiliary slide. 

As for the additional axis, the operator can consider mounting collet changer, hydraulic expansion, and multi-range chucks. When it comes to the collet changer which is highly automated, it is preferred to use clamping the workpieces with a variety of diameters with ideal concentricity in loader stations without any help from operators. 

With the advanced clamping technique, the 5-axis CNC grinding machine can consistently process the roughing or finishing operations since the accurate positioning jobs of symmetrical workpieces are pre-set. The CNC grinding machines are commonly utilized to produce components for medical, automotive, aerospace, and other industrial production lines. Thanks to modern grinding technology, significantly hard and exotic materials, as well as complex machining, are no longer problems for the 5-axis grinding machines.

5 Axis Tool Grinder Example

Farman Machinery is a grinding specialist located in Taiwan. They are especially renowned for their grinders specifically design for the manufacture of cutting tools. Today over 800 units of their Hawemat series CNC tool grinding machines are used around the world.

The Hawemat 3000 is a state-of-the-art metal and woodworking tool grinder that is suitable for a wide range of industries including medical and automotive. A direct dirve motor on the B axis and the full mineral compound machine structure make it a unique machine with highest precision and rigidity.

The Hawema kinematics concept is patented and allows for short travel paths, compact design, modular construction, as well as optimal cycle times. These features in combination with the NUMROTOplus controller give you the best 5 axis tool grinding capabilities. Visit the Farman website to learn more!

Cutting Tools Used in a 5-axis CNC Grinding Machine

In a 5-axis CNC grinding machine, there is a large range of tools with complex geometries that can be added to the equipment in order to cut rapidly and precisely, forming unlimited customized profiles. For example, the gun drilling tools, the hob cutters, the typical grinding wheel, and other micro or intricate tools. These cutting tools that can be used for 5-axis machining in a CNC grinding machine can be operated at a high rotational speed, which can be up to 4000 rpm. Following is the introduction of different grinding tools mentioned here.

● Grinding Wheel: 

For starters, a grinding wheel is the typical grinding tool that can provide different sorts of grinding options. The grinding wheel that is driven by power and rotates at the desired speed moves around the metal parts which are generally fixed with clamping units. There are also cases that the grinding head is stationary while the workpieces move on the axes for multi-face machining. 

While using the grinding wheel, the operational rate is not only defined by the operator but the diameters and qualities of the grinding wheels. As a result, to keep the conditions, refreshing the face of the grinding wheel, dressers which can be table-mounted or mounted near the head are popular to be added in the equipment. 

Some common materials which the grinding wheels are made of are silicon carbide, diamond, aluminum oxide, or cubic boron nitride. Among them, since aluminum oxide is more economical, so the material is the most classic and common one in the market. 

● Gun Drilling Tool: 

The tool is a rod that is produced with flutes, having a hole bored down at the center, where the coolant is delivered and pumped out via the hole of the machines. The flute, while cutting, will carry the metal chips with it.

● Hob Cutter: 

Hob cutters are also called hobs, which can cut the workpieces via the helical cutting teeth. The teeth of hob cutters have grooves that run along the hob’s length, assisting in both cutting and chip removal.