What is the spindle?
The main rotating part of the milling machine that transmits power to the cutting tool is called the milling spindle. Milling is a machining process in which the working piece moves due to the rotating tool with cutting edges to remove the material. When the cutting spindle rotates the cutting tool, the work is fed from different directions to form the desired shape. The end opposite the cutting end is mounted in the spindle of the milling machine to align and support the tool and provide power and rotation. A number of spindle adapters, wheels and other tools for connecting the tool in the milling spindle are available. The vertical machine is mounted parallel to the support column of the mill while shifting, which can move up and down. Many modern vertical mills have heads that can be rotated to place a spindle for cutting on an angle.
milling spindle in horizontalThe machine is usually in a fixed position with an engine located in the mill column. In the horizontal machine, the spindle cannot usually be reorientated as some vertical machines allow. However, the horizontal machine may have a table that can be rotated to change the spindle angle relative to the workshop. On some machines, a vertical spindle connection can be used to convert a horizontal mill for vertical configuration.
Spindle milling speed must be appropriately set for safe operation of the machine and prevent damage to the tool or work. Mill manufacturers can provide recommended values or can be calculated for a specific tool used and processed material. Speed is usually set using a dial or hand crank on the machine. Modern machines can allow continuous adaptation via a range of speeds, while older models may have a limited number of specific settings.
milling machines may under certain conditions suffer from excessive vibrations called chattingand. Chatter can make it difficult or impossible to make machining and damage the tool. The common cause of chatting is when the spindle speed is set too high. When reducing speed, it will not correct the condition, the problem can be caused by an unbalanced tool, free accessories or other problem.
A simple mill can only have one spindle, while more complex machines can include more spindles. More than one spindle allows cutting in two or three dimensions without moving the workpiece. Modern computer numeric controlled (CNC) machines used in comprehensive milling operations often include three or more milling of spindles for faster and increased permeability.