Cutting tool materials mainly include high-speed steel, cemented carbide, cubic boron nitride, artificial diamond, etc. Vapor deposition technology is currently widely used to improve cutting performance and tool durability. Modern CNC lathes have widely used machined carbide turning tools, and gradually began to use carbide coated turning tools.
CNC lathe operators must have a deep understanding of the selection of lathe cutting amount:
The programming of CNC lathe manufacturers is to reflect the programmer’s process intention through the program. How to correctly select the turning amount plays a key role in the processing economy of parts and the formation of the final accuracy of parts. For rough machining, the turning amount should be selected according to the processing economy of parts. For rough machining, the turning amount should be selected according to the processing accuracy of parts, especially the surface roughness.
The cutting amount used in turning includes: reverse feed amount ap, spindle speed S or cutting speed VC (for constant linear speed cutting), feed speed VF or feed amount f. These parameters should be selected within the allowable range given by the machine.
- Determine the back cutting amount ap (i.e. cutting depth): When the rigidity of the machining system and the power of the lathe allow, a large amount of back cutting can be selected on the ruler to reduce the number of feeds and improve production efficiency. At the same time, it can reduce the machine tool stall (mainly the backlash of the screw). The impact on machining accuracy. Economic CNC machine tools using stepper drive feed servo systems must avoid excessive stepping and step loss.
- Determine the spindle speed: The spindle speed when rotating on a smooth surface The spindle speed should be selected according to the selected reaction force, feed amount and tool durability. Generally, CNC lathe manufacturers claim that it can be calculated according to empirical formulas. According to production practice experience, you can refer to the relevant manual to understand the cutting amount within the cutting speed range allowed by the machine manual. It should be noted that the low-speed output torque of the CNC machine tool using AC variable frequency speed regulation is very small, so the cutting speed cannot be too low.
In actual programming, after determining the cutting speed VC, the spindle speed n can be calculated according to the formula n = 1000vc / eD. In CNC systems with different spindle speeds when turning threads, different spindle speeds should use different spindle speed ranges. The most economical CNC lathe recommends a rolling mode spindle speed of n “1200-k type p-initial thread pitch, mm; k-insurance factor, usually 80.
- The feed speed directly affects the roughing value and turning efficiency of the workbench. Therefore, under the premise of ensuring the quality of the workbench, a higher feed speed should be selected. According to the surface roughness of the part, the material of the tool and the workpiece, etc., please refer to the cutting amount for manual selection.
