What is Flat Bed CNC Lathe and Slant Bed CNC Lathe

Flat bed CNC lathe is mainly used for heavy-duty turning and is widely used for machine complex geometries, short shafts, discs, and other workpieces. In addition, it can machine a variety of internal and external threads in metric or imperial units. When the rotary head is mounted on the flat bed CNC lathe, it can mill or drill the circumference and end face of the workpiece. The flat bed CNC lathe can not only turn the outer circle, slot, and chamfer, but also drill, ream, expand and roll. It has an excellent machining range, stability, and productivity.

Slant bed CNC lathe is usually equipped with a multi-station turret or live tooling, which is an automatic machine tool with increased precision, high speed, and high accuracy. The slant bed lathe is most suitable for manufacturing small and medium-sized parts in prototype or series production, such as aircraft and automobiles, and can also be used for machining linear cylinders, slant cylinders, circular arcs, and various complex parts, such as threads and grooves. One of the well-known advantages is the superior chip removal performance. Chips generated during CNC turning or milling are flushed to the chip bed by gravity and the flow of coolant. Furthermore, this feature also reduces undue wear on the guides and other moving parts, which will extend the life of the machine.

Machine Layout

The two guide rails of flat bed CNC lathe are parallel to the plane of the ground. The plane of the two guide rails of the slant bed CNC lathe intersects with the plane of the ground to form a slanting plane with angles of 30°, 45°, 60° and 75°. From the side of the machine, the flat bed CNC lathe bed is square, and the slant bed CNC lathe bed is a right-angle triangle. Obviously, with the same width of the guide rail, the x-direction travel of a slant bed is longer than that of flat bed. Therefore, the benefit to the slant bed lathe is that more tool alignments can be arranged.

Hard Turning Performance

The cross-sectional area of the slant bed CNC lathe is larger than that of flat bed with the same work envelope, i.e., it has stronger mechanical resistance to bending and torsion. The cutting force is basically the same as the direction of gravity of the workpiece, so the spindle is running more smoothly and it is not easy to cause turning vibration. While turning with flat bed CNC lathe, the cutting force generated by the tool and the workpiece is 90° with the gravity of the workpiece, which is easier to cause vibration.

Machining Accuracy/Repeatability

The linear guideway & high-precision ball screw contributes to the accuracy of the CNC slant bed lathe. although the transmission gap between the screw and the nut is very small, there is a certain clearance. When the screw moves in the reverse direction, it will inevitably produce reverse clearance which impaired the positioning repeatability, thus affecting the machining accuracy. The layout of the slant bed CNC lathe can directly affect the clearance of the X ball screw, and gravity acts directly on the axial direction of the screw so that the reverse clearance of the transmission is almost eliminated. Conversely, the x-directional screw of the flat bed CNC lathe is not affected by the axial gravity, and the clearance cannot be eliminated directly. This is the inherent advantage brought by the design of slant bed CNC lathes.

The Convenience of Chip Removal

The slant bed CNC lathe is benefit from gravity, so it is convenient for the chip removal; at the same time, it comes with a protection cover, which can avoid the accumulation of chips on the screw and guideway. The flat bed structure required extra labor for the chip removal.

Possibility of Automatic Solutions

Thanks to a capacious work envelope, the feature rich slant bed CNC lathe is capable of outfitting the various tool arrangements, like the possibility of side live tooling on the X-axis. Due to the easy chip removal ability, it provides a lot of possibilities for automatic solutions like the bar feeder, gantry loading device, or robotic arms.