Ramp milling
Ramp milling is an effective way to mill a concave cavity or hole in a solid body. Figure 6-6 is a schematic diagram of ramp milling. Ramp milling is when the cutter moves down along its own axis while the cutter moves in the direction of the vertical cutter axis. The trajectory of the two forms an E angle between the movement trajectory and the conventional milling plane.
The maximum depth of cut for ramp milling of a milling cutter is related to the size of the insert. If the required depth of cut exceeds the value of a, as illustrated, you should first cut to a depth equal to the value of a, with an end mill, and then complete a plane at an angle of a-0°. Once this plane is complete, re-enter the next loop. The E angle of ramping is affected by the rear angle of the cutter. This cutter relief angle is the angle at which the cutter body angle is combined with the cutter insert angle. In general, most of the flat-mounted negative insert milling cutters can not be sloped milling, and most of the recommended for slope milling are inserts with larger relief angles, such as inserts with 15° relief angles and inserts with 20° relief angles, because when using larger inserts, the composite relief angle of the milling cutter will be relatively large. As a rule of thumb, the permissible E-angle of ramp milling should be at least 2° smaller than the cutter relief angle.
