Home / CNC Technology (page 4)

CNC Technology

SURFACE GRINDING BASICS

Horizontal spindle surface grinding is becoming ever more important as equipment and machined parts are miniaturized and dimensional tolerances shrink. A few years ago, ;.0001 in. was considered a close tolerance. Now, half that amount (.000050 in.) is seen more frequently on drawings, especially in the advanced technology areas. These pressures for increasingly closer work are …

Read More »

GRINDER CHUCKING SETUPS

Odd-Shaped Workpieces A magnetic or vacuum chuck will exert the most reliable holding power on an odd-shaped workpiece, if the area of contact with the chuck is large enough. Whenever possible, place the workpiece so that the largest surface area possible is on the chuck. Sometimes it is necessary to block a small or thin …

Read More »

CARE OF GRINDER CHUCKS

Like much of the equipment found in the machine shop, grinder chucks are precision tools and deserve the same care and handling you would give your precision measuring instruments. With reasonable care they will maintain their accuracy over many years. Observe the following precautions when using grinder chucks. Step 1 Carefully clean the chucking surface before …

Read More »

TYPES OF GRINDER CHUCKS

Magnetic Chucks The most common work-holding device for the surface grinder is the magnetic chuck. The three types are the permanent-magnet (Figure L-79), the electromagnet (Figure L-80), and the electro-permanent-magnet chuck.Permanent-magnet chucks, which are the most widely used chucks in the job shop setting, are composed of a series of alternating plates consisting of powerful …

Read More »

ACCESSORIES

The versatility of the horizontal surface grinder can be extended by the use of accessory equipment. Several of these pertain to work holding and will be discussed in the next unit. Accessories that increase the grinding capability of the machine include the following. Centerless grinding can be accomplished using the centerless attachment (Figure L-77). Parts …

Read More »

IDENTIFYING MACHINE PARTS AND THEIR FUNCTIONS

The horizontal spindle reciprocating table surface grinder (Figure L-74), often simply called a surface grinder, presents the periphery of the grinding wheel to the workpiece. The workpiece is mounted on a table that moves back and forth under the wheel. Major parts of this grinding machine include the following. Wheelhead The wheelhead contains the spindle, bearings, …

Read More »

CLEANING THE GRINDING FLUID

However, many grinding machines have self-contained grinding fluid systems. Several methods are used for grinding fluid cleaning. Cleaning of the fluid should be carefully done and monitored. A fundamental technique is settling. Grinding fluid is pumped to the settling tank, where swarf settles out by gravity. Settling tanks should have a series of baffles and enough …

Read More »

METHODS OF APPLICATION

Most grinding fluids are applied in high-volume, lowvelocity flood streams (Figure L-66) by the machine coolant pump. The grinding fluid is constantly recirculated and cleaned of swarf (Figure L-67). The supply must be replenished from time to time with makeup mixture and additives. It is important to apply grinding fluid at the right place (Figure L-68). This is usually at the …

Read More »

TYPES OF GRINDING FLUIDS

Water-Soluble Chemical Types Water-soluble chemical types of fluids, called synthetic fluids, are typically mineral-oil free. They are usually transparent, which helps with visibility. Some are compounded to provide good rust control; others are chemically active, to promote cutting, and can damage machines that are not carefully maintained. They are not prone to bacterial growth. They provide …

Read More »

BALANCING

Balancing is usually required on large wheels (over 14-in. diameter) but may not be required for smaller wheels. An out-of-balance wheel can cause chatter marks in the workpiece finish. Wheels are balanced on an overlapping disk balancing tool (Figure L-63) or parallel ways (Figure L-64). The parallel ways balancing tool must be set to a …

Read More »