Selection of milling machine milling amount, first selection of back cutting depth and side cutting depth is bigger, then choose the feed per tooth larger, and finally determine the milling speed.
(1) Cutting depth
The cutting depth is selected according to the machining allowance, the machined surface quality and the milling machine power.
When the power and rigidity of the machine are allowed, it is usually economical to cut all the machining margins with one feed.
For the cylindrical milling cutter, the cutting depth is side cutting depth. For face milling cutter, the cutting depth is back cutting depth.When the processing margin is less than 5~6mm, a knife can be milled all the processing margin; if the processing margin is greater than 5mm, size accuracy requirements are high, can be divided into thick, fine two pass, the second time Knife to take 0.5~1mm.
(2) Feed amount
Feed amount is based on the workpiece surface roughness, processing accuracy and cutting tools, milling machines, fixtures and other factors determined by the stiffness. Usually the following data can be used: high-speed steel cylindrical cutter, processing ordinary steel can take fz= 0.04~0.15mm; processing cast iron desirable fz= 0.06~0.5mm. High-speed steel milling cutter, processing ordinary steel is desirable fz= 0.04~0.3mm; processing cast iron desirable fz= 0.06~0.5mm. Carbide end mills and three blade milling cutter processing steel and cast iron, desirable fz =0.08~ 0.3mm.
After the fz value is determined, the feed rate can be calculated and the approximate value is selected by the value provided by the milling machine.
(3) Cutting speed
The cutting speed is determined by factors such as the material of the workpiece and the tool, the amount of cutting, the geometry of the tool teeth, and the durability of the tool. Usually can be found from the manual, or calculated by the empirical formula.
When milling steel with a carbide cutter, the milling speed is 3~5m/s; Milling speed up to 6~10m/s; milling cast iron, improve the milling speed on the surface quality improvement is not significant, so the milling speed is lower. With high-speed steel cylindrical milling cutter milling, the milling speed is generally 0.3~1m/s.
According to the selected milling speed, converted into the corresponding number of revolutions, and then press the milling machine marked on the speed selected.