Tag Archives: milling advance

Manual Data Input Manual data input, or MDI, as its name implies, is the mode in which program data may initially be entered using the CNC’s keyboard. MDI mode also allows for editing or deletingn existing program data. A complete block or complete program may be entered and run in MDI mode. However, once the data are …

In incremental mode, each programmed motion is independently measured from the previous point (Figure M-35). For example, the drawing shows a four-hole pattern with each feature dimensioned relative to the other features. If the part were to be drilled starting from the setup point indicated, each tool positioning move would be an increment equal to the drawing dimensions. Positioning from the …

The workpiece in on-centers cylindrical grinding is mounted between the head and footstock centers. This effectively provides a single point mounting on each end of the workpiece, permitting maximum accuracy to be achieved in the grinding operation. The angle and finish of center holes in the workpiece is extremely important. The results of a cylindrical grinding job depend on …

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 …

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 …

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 …

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 …

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 …

When a new wheel is installed on the grinder, it must be trued before use. The cutting surface of a new wheel will run out slightly due to the clearance between the wheel bore and machine spindle (Figure L-51). Truing a wheel will bring every point on its cutting surface concentric with the machine spindle. …

Concentration is a term applied to superabrasive grinding wheels that refers to the amount of abrasive contained in a unit volume of usable grinding wheel. A concentration of 100 corresponds to 72 carats in a cubic inch of wheel in the effective superabrasive volume of the grinding wheel. The concentration values are usually between 30 and 175. …