A surface grinder is used extensively in abrasive machines to create a flat, hard finish on many flat surfaces. It’s a widely applied industrial abrasive machining method in which a rotating diamond-crowned wheel containing coarse crystals of carbon is used to cut irregularly shaped pieces of metal or non-metallic material from a workpiece. The abrasive is directed onto the workpiece at high speeds, causing the workpiece to be ground at high temperatures. This is known as abrasive blasting. The work piece is moved around, so that the grinding speed of the diamond wheel can reach the work surface at a specific angle. This results in a perfectly flat and smooth finish.
There are two types of grinding in surface grinder operation – vertical and horizontal. Both use identical methods to grind workpieces but with different means of application. Vertical grinders operate in much the same way as table saws, with the workpiece placed between two vertically mounted rotary vane spindles. The discs rotate in a similar pattern as those of a jigsaw and are held in position by a set of pins. In horizontal grinders, the vane discs are arranged in a vertical plane and the work surface is positioned above the rotary discs. The surface grinder is then moved over the workpiece and the grinding operation starts.
Grinding machines using diamond-crowned wheels of variable speed and diameter are also available and can be used for grinding wide varieties of materials. Some grinders may also incorporate the use of a variable-speed CNC milling machine to accelerate the grinding process, producing faster and more accurate results. The most common types of surface grinders are single-stage units, and there are two general types of CNC grinders: fully automatic (with a trigger) and semi-automatic (with a knob). Fully automatic grinders usually have an in-built programmer that controls the CNC machine’s operation; this enables the operator to specify desired grind speeds and other CNC operation parameters.
A CNC surface grinder may be fixed or mobile, and may have several functions. Fixed grinders are fixed to a particular stand and remain in position during operation. Mobile grinders are able to move about freely, and the angle of movement may be varied according to the operator’s preference. They can even be dismantled completely, allowing you to move to another work surface quickly. The fixed styles are used more often when the surface to be ground is extremely hard or soft. These types of grinders are also typically fitted with diamond-tipped grinders for scoring and polishing hard surfaces.
Some grinders are made in a way that allows for the attachment of accessories. Attachable accessories include diamond-tipped grinders that score surfaces and also the blades of grinders can be detached and attached to handheld tools for scoring and cutting purposes. Other attachments are available for use with electric grinders, including grinders with paper towel hosing attachments that are useful for cleaning up areas not cut into, and grinders with rotary brush capabilities that enable the smoothest finish possible on many surfaces. Automatic and semi-automatic grinders are also available with interchangeable cutting surfaces and grinding wheels.
Another common type of CNC surface grinder is the abrasive wheel. The abrasive wheel uses a continuous belt that is stretched over a bed of stone to grind away at hard materials, such as ceramic tile, granite and marble. This type of grinder produces very little waste and the grinding process can be continuous, which makes it ideal for small projects. Some types of CNC abrasive wheel grinders use an electric motor to provide the grinding action. In some CNC grinding machines, the user controls the amount of grinddust produced. However, most of these units can only grind light materials, such as metal.