The used combination milling machine is a conventional machine tool that is essential for the machining of parts by metal cutting. It is available in different types, suited to different kinds of work, from the simplest to the most complex. Everything depends on the machine tool you choose.
What is a conventional milling machine?
Milling is one of the most common machining operations: it removes chips using a rotating tool fitted with one or more cutting edges, known as a milling cutter. Milling is one of the most widespread and oldest machining processes, but a used combination milling machine does more than mill: it can also perform other operations such as drilling and slotting.
In addition, used combination milling machines can work a wide range of materials. They can machine wood, as well as ferrous and non-ferrous metals: stainless steel, cast iron and so on. They can also machine all kinds of parts, whatever their shape: flat, curved, slotted, toothed and so on.
The milling machine reduces machining times, which speeds up production and also lowers production costs.
What is a milling machine used for?
Besides milling, these machine tools are used to produce slots, moulds, hinges and more. Work machined on them delivers excellent results, as the finishes are smooth and fine, of high quality, thanks to the rotational speed of the cutters. That is why milling machines are often also used as drilling machines to machine holes.
How many types of milling machine are there?
If you are looking for a used combination machine for milling work, the conventional milling machine is the machine tool you need: it is very versatile, easy to use and offers many advantages. However, there are other types of milling machine available today, classified by the position of the tool, as special milling machines, and by the number of axes along which the cutting tool moves.
In the classification by tool position, there are:
- Horizontal milling machines.
- Vertical milling machines.
- Universal milling machines, which combine the horizontal and vertical types.
By number of axes, milling machines can have three, four, five or even six axes. Each additional axis makes the workpiece more accessible to the cutting tool. Thanks to the A and B axes (fourth and fifth axes), the workpiece can be tilted and rotated to different angles, making it easier for the cutter to machine. These are the most advanced milling machines.
Special milling machines include the gantry type, which is very large and is used to machine large parts, generally for the automotive industry. Another type is the computer numerical control (CNC) milling machine, which delivers high precision on the parts being machined.
How to use a used combination machine
The used combination milling machine is very easy to use, although operating it calls for the experience of a skilled turner and miller. First, fit the cutter in the machine head; this can be a milling cutter, but also a drill bit if you want to make slots in the part. To fit the cutting tool, the machine must be unplugged and the spindle locked. Loosening the spindle requires a spanner, which should be supplied with the milling machine. Once the cutter is in place, the spindle can be tightened again.
Before you start milling, it is important to set all the machining parameters. This includes setting the cutting depth and speed. To do so, use the machine's own built-in aids, such as the feed handles that let you adjust the height you want until you reach the machine's stop.
Once the milling machine and the cutter have been set up, it is time to mount the workpiece. The workpiece can be held with any workholding and clamping system, although the milling machine itself already includes a chuck to which the part is secured. The workpiece must be firmly immobilised: remember that the machine runs at high speeds, which generate vibrations in the machine, and the machining results may not be as intended.
All that remains is to start the machine and begin machining. Bear in mind, for example, the cutting direction when using the cutting tool; it should always be opposite to the rotation of the cutter. For higher-precision machining, you can add other elements and accessories such as a rotary table for milling machines; this graduated device lets you drill series of holes at a specific spacing. It makes the work much easier.