One of the most commonly used machines in the manufacturing industry is the milling machine, which has a rotating cutting tool that is used to remove unwanted material from a stationary workpiece. It is used for drilling, grooving, boring, producing slots, and shaping metals and irregular surfaces. The materials that can be used for milling machine are metal, wood, and plastics, depending on the complexity and requirements of the specific design. In the milling process, the material always remains stationary while a rotating cutting tool is pressed against it. Now, the introduction of Computer Numerical Control (CNC) made way for many useful features such as performing lathe machine jobs for plate metal fabrication. There are two different types of milling machine: the vertical and horizontal milling machine.
The vertical milling machine is the most common type of milling machine, which has a vertically oriented spindle that holds, moves up and down, and rotates the cutting tool against a stationary workpiece to remove unwanted material. Its base is made up of cast iron with high compressive strength and attached to it is the screw jack that moves vertically. It has low efficiency and there is still a need for the operator’s attention or manual movement to cut in different directions but it’s a low-maintenance with high functionality machine. A vertical milling machine has two distinct types: the turret milling machine and bed milling machine. A vertical turret milling machine works through a fixed spindle and table that moves perpendicular and parallel to the axis. It is versatile because it can be easily adjusted and maneuvered, making it able to perform a wider range of milling operations than bed milling machines which only moves the table perpendicular to the axis of the spindle. The spindle moves up and down and the bed can only move horizontally but the bed milling machine is better for bigger workpieces.
Although mostly used for metallic workpieces, plastics and other materials can also be machined by a vertical milling machine. It can be operated manually, CNC, or a combination of both. Aside from milling, it can also be used in drilling, boring, plunge cutting, and slotting or keyways.
Another type is the horizontal milling machine. Like a vertical milling machine, it also has a spindle containing a rotating cutting tool that presses against a workpiece to remove unwanted material. However, the most evident difference of the two is their spindle orientation. As the names suggest, the spindle of the horizontal milling machine features a horizontal orientation while the vertical milling machine features a vertical orientation. A horizontal milling machine usually has short and thick cutting tools which are ideal for materials that are heavy and hard to work through, and in making thicker or deeper grooves. Its base is made up of gray cast iron and it has an arbor, which is an extension fitted inside the spindle that transfers the rotational motion of spindle to the cutter. Its finished products have smooth surfaces that require less fabrication, and the cutting chips can be easily removed.
Horizontal milling machines can also be operated manually, CNC, or combination of both. Many horizontal mills have a universal table or a built-in rotary table that allows milling at various angles, so using this machine is similar to using various machine tools at once.
These two machines are good investments for a business but there is a need to analyze both the advantages and disadvantages of the machines. Some of the differences between the two are:
- Vertical and horizontal milling machines have different cutting tools, the former usually have long and thin cutting tools while the latter have shorter and thicker cutting tools. Vertical mills are ideal for milling more detailed parts and cuts that have greater need for accuracy, while horizontal mills are ideal for cutting bigger, heavier, and deeper grooves into the material.
- Horizontal milling machines are faster than vertical milling machines, because horizontal mills have shorter processing time per part and can perform or reach three faces of a part in one cycle.
- When it comes to the cost, horizontal milling machines are more expensive than vertical milling machines. However, it does not need a lot of people to run horizontal mills. On the other hand, vertical milling machines are cheaper, useful for less complex tasks, and can mill at detail so it is good for small businesses.
- Vertical milling machine reduces while horizontal milling machine increases the tool life.
- Vertical milling machine is lighter in weight and suitable for smaller areas while horizontal milling machine is heavier in weight and requires a larger area.
- Chips are not properly removed in a vertical milling machine, while these are easily removed and thrown away from the machine in a horizontal milling machine.
- Vertical milling machines are more common and versatile especially when the machining is to be carried out on a single plane, while horizontal milling machine is suitable for complex projects, high-cheap removal, heavy-duty work, and machining multiple sides at varying angles.
Both machines have their own advantages and disadvantages and although it is important to learn about these, it should not be the only focus of those people who want to purchase these machines. They should also consider the nature of their business – particularly the size of the company and the area where the machines will be placed, the money they are willing to allot for purchase and maintenance, and what type of jobs they require from the milling machine. If you’re interested in purchasing a milling machine, browse our extensive inventory of used vertical milling machines and used horizontal milling machines. Contact us at Tramar Industries and we’ll help you find the right machine for the job.