A hard edged tool made out of diamond or another natural stone that has the ability to grind small holes into concrete or other hard surfaces is called a surface grinder. It is used to create a fine, even finish on hard flat surfaces. It is an extensively used rough abrasive metallurgical procedure where a rotating diamond-tipped wheel containing rough grains or chips is used to cut tiny holes into a workpiece, producing a contoured face of it smooth or flat. The abrasive material used in this process is usually ground at high speeds and under pressure.
Grinding machines use different methods of operation, depending on the material to be printed. Vertical grinders are used for cutting hard surfaces, while horizontal grinders grind smaller particles into fine powder. There are also self-grinding grinders that run without mechanical aid from an electric motor. Conveyor grinders are used in line grinders and in grinders that are operated via a manual crank or by a string trimmer. There are also hand-operated surface grinders in numerous models that use a mechanism to move the grinding tool along the surface, similar to a belt-driven vehicle.
The principle of operation of a surface grinder is similar to that of a milling machine. The hard, flat workpiece is placed inside a rotating drum or shaft at high speeds, producing high pressure inside a sealed chamber. Here, the workpiece is subject to a grinding effect, in which the workpiece is forced into a rough or ‘tumbled’ surface. This causes the workpiece to generate a layer of burr, a fine layer of material, on the flat surface. This layer of burr is the product of the grinding action, which grips the surface tightly, polishing it in its entirety.
This product of grinding wheels has two types, one being a tumbling type and the other being a percussion type. The tumbling type of surface grinder is common in small shops and home workshops. In this type, the tumbling action of the grinding wheel propels a small chuck that rolls along the work piece, imparting wear and tear on the work surface. The work piece can be moved on the ground in order to repair small chips or other defects in the design.
While a tumbling surface grinding machine is convenient for smaller tasks, it can be a problematic option when the workpiece is of a larger size. In order to work with a large sized piece, the drum must be made of solid steel or other durable metal. Large machining centers, however, have the capability of producing large diameter and heavy duty grinders. They have the necessary power and the necessary space to handle the task. In some instances, they may even be able to turn the work into a horizontal operation by using a floating center.
One of the more unique types of surface grinding machines is the one which uses a CNC machine. A CNC (Computer Numerated Control) machine can be programmed to do just about anything. It can cut, drill, move, chisel, polishing and etching. These types of grinders are ideal for use in robotic fabrication where exact measurements and precision are required. There are some drawbacks to using a CNC surface grinder, however, such as the inability to use the same CNC program on different sized workpieces.