The basic conditions required for the operation of lathe cutting are spindle speed S, feed amount F, and feed depth. Only by meeting these three conditions can the normal operation of the CNC lathe cutting system be guaranteed. Below, our CNC lathe manufacturer will introduce the three basic elements of lathe cutting operation in detail.

1、 Cutting speed (linear speed, circumferential speed) V (meters/minute)

To choose the spindle speed per minute, it is necessary to first know how much the cutting line speed V should be taken. The selection of V depends on the tool material, workpiece material, processing conditions, etc.

(1) Tool material:

Hard alloy: V can achieve a higher value, usually above 100 meters per minute. Generally, when purchasing blades, technical parameters are provided - how much linear speed can be selected when processing what materials.

High speed steel: V can only achieve a lower value, generally not exceeding 70 meters per minute, and in most cases, it is taken as below 20-30 meters per minute.

(2) Workpiece material: high hardness, low V value; Cast iron, with a lower value of V, can be used for cutting tools made of hard alloy, with a value of 70-80 meters per minute; Low carbon steel, V can be taken as above 100 meters per minute, while for non-ferrous metals, V can be taken as higher (100-200 meters per minute). For quenched steel and stainless steel, V should be taken as lower.

(3) Processing conditions:

Rough machining, take a lower value for V; Precision machining, take a higher value for V;

The rigidity system of machine tools, workpieces, and cutting tools is poor, and V is taken as low.

If the numerical control program uses S as the spindle speed per minute, then S should be calculated based on the workpiece diameter and cutting line speed V:

S (spindle revolutions per minute)=V (cutting line speed) * 1000/(3.1416 * workpiece diameter)

If the CNC program uses a constant line speed, then S can directly use the cutting line speed V (meters/minute)

2、 Feed rate (feed rate) F

It mainly depends on the surface roughness requirements of the workpiece processing. When precision machining, the surface requirements are high, and the cutting amount is taken as small: 0.06-0.12mm/spindle per revolution.

When rough machining, it is advisable to use a larger size. It mainly depends on the strength of the cutting tool, generally taking 0.3 or above. When the main back angle of the cutting tool is large, the tool strength is poor, and the feed amount cannot be too large. In addition, the power of the machine tool and the rigidity of the workpiece and tool should also be considered.

The CNC program uses two units of feed: mm/minute and mm/spindle per revolution. The units used above are mm/spindle per revolution. If mm/minute is used, the formula can be used to convert it: feed per minute=feed per revolution * spindle per minute

3、 Cutting depth

When precision machining on CNC lathes, the cutting depth is generally taken as less than 0.5 (radius value).

During rough machining, it is determined based on the condition of the workpiece, cutting tool, and machine tool. Generally, small lathes (with a maximum machining diameter of less than 400mm) turn 45 # steel in the normalized state, and the cutting depth in the radial direction generally does not exceed 5mm.

The above are the three basic elements of lathe cutting operation, hoping to be helpful for everyone in using lathe cutting systems in the future.