Planing(redirected from dental planing)
Also found in: Dictionary, Medical.
the process of machining materials, accompanied by chip removal; it is performed by the relative reciprocal motion of a tool, such as a planing cutter or blade, or of the workpiece. Chip removal usually occurs during the cutting stroke.
In planing metal, the cutting speed is defined as the speed vc (in m/min) of the straight-line motion of the cutter (on shapers, see Figure 1) or of the workpiece (on a standard planer) during the cutting stroke. The feed s (in mm per double stroke) is the lateral movement of the workpiece per double stroke of the cutter (on a shaper) or of the cutter per double stroke of the workpiece (on a standard planer). The depth of cut t (in mm) is the difference between the height of the machined surface and the height of the surface before machining. The production time for planing is defined as
where B is the relative movement (in mm) of the cutter or work-piece in the direction of feed, n is the number of double strokes per minute of the cutter or workpiece, and l is the number of passes of the cutter.
Multitool planing makes better use of a planer’s capacity (Figure 2). High-output finish planing uses wide planing cutters with auxiliary cutting edges set at an angle φ1 = 0c. The cutters have lengths 1.2–1.8 times greater than the length of the feed, and they are equipped with hard-alloy faces. Large feeds—up to 20 mm per double stroke—are used. Efficient cutting conditions for planing are determined by the same procedures used for turning; the proper correction coefficients must be taken into account.
The principal drawbacks of planing are the impact of the cutting tool at the beginning of each stroke and the presence of a return stroke, which decreases the tool life and the productivity of the operation.
In woodworking, planing consists in the removal of material in the form of shavings by means of hand woodworking tools, such as planes, and the working of wood to produce planed, one-ply veneers.
REFERENCESObrabotka metallov rezaniem, 2nd ed. Moscow, 1962.
Rezante konstruktsionnykh materialov, rezhushchie instrumenty i stanki. Edited by P. G. Petrukha. Moscow, 1974.
Arshinov, V. A., and G. A. Alekseev. Rezanie metallov i rezhushchii instrument, 2nd ed. Moscow, 1967.
D. L. IUDIN