A surface grinder is a machine tool that can be used to manufacture various kinds of surfaces and finish them in desired ways. There are many different types of grinders available on the market, but most of them have in common the ability to grind hard or soft materials at high speeds. This enables them to be used in a wide range of manufacturing applications where roughing or polishing a surface is required. Grinding wheels are usually fixed and there are two types – semi-automatic and automatic. The former are used when you need to manually control the speed of the grinding operation and the latter when the work piece has to be completely ground.
In general, the surface grinder consists of two parts. One part is the vertical spindle, which is fitted into a chuck with a grinding wheel positioned above the workpieces. The other part consists of rotating blades which are fixed to the spindle and also to the chuck. The vertical spindle and the blades are often powered by electric motors, while the workpieces may be operated manually.
Vertical grinders: The spindle and the blades of a vertical surface grinder are arranged vertically in such a way that the distance between them is equal to the distance between the centerline of the workpiece and the center of the chuck. This means that the workpiece is moved along a plane parallel to the surface. As the workpiece rotates, the grinder’s teeth pick up bits of unwanted material and deposit them in slots in the workpiece. The size of these slots depends on the size of the workpiece. The most popular vertical grinders are the rotary grinders, which have variable-speed drives and large cutting teeth.
Reciprocating grinders: A reciprocating surface grinder resembles a reciprocating saw, and this is often considered to be a subtype of the vertical grinder. The principle of operation is basically the same. The only difference is that the workholder moves the chuck and the grinding wheels along an inside path between two points. The workholder then exerts pressure on the grinding wheel and directs it over the work area. The result is a rough, level, and machined edge finish.
Magnetic Chuck: A magnetic chuck or stand-up grind (the name comes from the magnetic attachment used in its operation) is similar to a surface grinder but does not rely on any outside energy for its operation. It uses a magnetic chuck that contains a permanent magnet and can be moved around using a magnetic reed. The chuck rotates because of the force of the magnetic force applied to it by the reeds. A stand-up type of magnetic chuck is the only type of chuck found in applications where there is little or no mechanical power, and therefore the magnetic chuck is not suitable for use in mobile services. A stand-up grinding device is not suitable for use with computer-controlled CNC machines since it can become completely nonfunctional.
In order to achieve high-quality results, a good surface grinder should be able to perform both wet and dry grinding. The dry grinding type of grinding is very different from the wet grinding type due to the fact that it usually requires a solvent or water-based solvent to clean the workpiece before it is ground. The advantage of wet grinding is that it generates higher speeds and produces larger beads. The most common material used in wet grinding is abrasive metallic (also known as scouring) steel.