How to Use a Tool and Cutter Grinder

A tool and cutter grinder is used to sharpen the edges of tools that have gone dull. The tool and cutter grinder is not a toy and takes special care and training in order to operate correctly. The tool and cutter grinder is also a rather large machine found in machine shops. It is recommended to take your tools to a professional to grind and sharpen them. The following article will explain how a professional operates a tool and cutter grinder machine.

Step 1 - Prime the Machine

It is always a good idea to turn the tool and cutter grinder on to warm it up. A cold grinder will create rough cuts while a warm or hot grinder disc will produce the best result. Allow the tool and cutter grinder to run for several minutes before taking tool to the grinding disc.

Step 2 - Safety Precautions

Just looking at the tool and cutter grinder suggests a medieval torture device. There are a lot of moving parts, guides and rails to worry about as well as the grinding disc itself. Always wear heavy work gloves when using the machine. You also need to wear safety goggles. The grinding disc is typically abrasive and made with diamonds. When grinder begins to sharpen the tool it can cause small fragments of the tool, the disc or sparks to fly toward your face. Getting any of these superheated fragments in your eye can be very dangerous.

Step 3 - Examine the Tool

Not all tools are made the same and it is important to examine the tool you are about to use the tool and grinder cutter on. You are looking for the angle of the tool, including which way the blade is curved, how the edges are cut and the contact points. This is incredibly important because to properly use the tool and cutter grinder you need to know what direction the tool needs to go. If you fail to do this, you can severely damage the tool you are trying to bring back to life.

Step 4 - Using the Tool and Cutter Grinder

Double check all of your safety areas and examine your clearance. The kind of tool you are using will determine what the settings need to be. For this information you should always consult the instruction manual that came with the machine you have access to. Not every tool and cutter grinder is the same when it comes to this. Turn the machine on and keep a safe distance from the grinding disc. Remember the curvature of the tool you are sharpening and place it against the grinding disc at the appropriate angle. A knife, for example, would be approximately 45 degrees. Use short movements and firm pressure until you are satisfied it is sharp.

Tool and cutter grinder

A tool and cutter grinder is used to sharpen milling cutters and tool bits along with a host of other cutting tools.
It is an extremely versatile machine used to perform a variety of grinding operations: surface, cylindrical, or complex shapes. The image shows a manually operated setup, however highly automated Computer Numerical Control (CNC) machines are becoming increasingly common due to the complexities involved in the process.
The operation of this machine (in particular, the manually operated variety) requires a high level of skill. The two main skills needed are understanding of the relationship between the grinding wheel and the metal being cut and knowledge of tool geometry. The illustrated set-up is only one of many combinations available. The huge variety in shapes and types of machining cutters requires flexibility in usage. A variety of dedicated fixtures are included that allow cylindrical grinding operations or complex angles to be ground. The vise shown can swivel in three planes.
The table moves longitudinally and laterally, the head can swivel as well as being adjustable in the horizontal plane, as visible in the first image. This flexibility in the head allows the critical clearance angles required by the various cutters to be achieved.

CNC tool and cutter grinder

A modern CNC tool grinder with automatic wheel pack exchanger and tool loading capabilities.

Today's tool and cutter grinder is typically a CNC machine tool, usually 5 axes, which produces endmills, drills, step tools, etc. which are widely used in the metal cutting and woodworking industries.

Modern CNC tool and cutter grinders enhance productivity by typically offering features such as automatic tool loading as well as the ability to support multiple grinding wheels. High levels of automation, as well as automatic in-machine tool measurement and compensation, allow extended periods of unmanned production. With careful process configuration and appropriate tool support, tolerances less than 5 micrometres (0.0002") can be consistently achieved even on the most complex parts.

Apart from manufacturing, in-machine tool measurement using touch-probe or laser technology allows cutting tools to be reconditioned. During normal use, cutting edges either wear and/or chip. The geometric features of cutting tools can be automatically measured within the CNC tool grinder and the tool ground to return cutting surfaces to optimal condition.

Significant software advancements have allowed CNC tool and cutter grinders to be utilized in a wide range of industries. Advanced CNC grinders feature sophisticated software that allows geometrically complex parts to be designed either parametrically or by using third party CAD/CAM software. 3D simulation of the entire grinding process and the finished part is possible as well as detection of any potential mechanical collisions and calculation of production time. Such features allow parts to be designed and verified, as well as the production process optimized, entirely within the software environment.

Tool and cutter grinders can be adapted to manufacturing precision machine components. The machine, when used for these purposes more likely would be called a CNC Grinding System.

CNC Grinding Systems are widely used to produce parts for aerospace, medical, automotive, and other industries. Extremely hard and exotic materials are generally no problem for today's grinding systems and the multi-axis machines are capable of generating quite complex geometries.

Radius grinder

A radius grinder (or radius tool grinder) is a special grinder used for grinding the most complex tool forms, and is the historical predecessor to the CNC tool and cutter grinder. Like the CNC grinder, it may be used for other tasks where grinding spherical surfaces is necessary. The tool itself consists of three parts: The grinder head, work table, and holding fixture. The grinder head has three degrees of freedom. Vertical movement, movement into the workpeice, and tilt. These are generally set statically, and left fixed throughout operations. The work table is a T-slotted X-axis table mounted on top of a radial fixture. Mounting the X axis on top of the radius table, as opposed to the other way around, allows for complex and accurate radius grinds. The holding fixtures can be anything one can mount on a slotted table, but most commonly used is a collet or chuck fixture that indexes and has a separate Y movement to allow accurate depth setting and endmill sharpening. The dressers used on these grinders are usually quite expensive, and can dress the grinding wheel itself with a particular radius.

D-bit grinder

D bit grinder

The D-bit grinder is a tool bit grinder that specializes in the grinding of D-bit cutters for pantograph milling machines. Pantographs are a variety of milling machine used to create cavities for the dies used in the molding process, they are being rapidly replaced by CNC machining centers.