Milling

Since 14 May 2012, we are able to mill workpieces up to 7,000 x 1,200 x 1,300 mm (X Y Z) in our sister company Tosec. This milling machine has 5 axes! Please contact us if you need milled parts with such dimensions! Our extensive machinery at Rime in Riesa also includes a milling machine, with which we can mill metal sheets up to 1,800 x 920 x 720 mm in size.

NEW! In October we will put our new machining centre with 5 axis in operation.

  • extreme large workspace
  • X, Y, Z-travel (4,200/3,630 x 750 x 695/800 mm)
  • circular table with a diameter of 750 mm
  • interference area: 1,100 mm
  • shuttle operation: 2 x 1,800 mm
  • swivel range (± 98°)
  • automatic acess to up to 50 tools
  • high milling performance with high precision
  • processing long and bulky parts

Our machining centre is not so large and has a working range of 1,800 x 920 x 750 mm. It was purchased in January 2010, and has 3 axes and is set up to mill complete assemblies. The workpiece is designed in our CAD department using 3D software; it is then written in a CNC program and transferred to the computerised control of the milling machine. This control ensures the greatest possible accuracy during milling. Sheet metal parts can be milled in all three workspace coordinates, depending on the requirements. This means that all axes, depending on the requirements, can be controlled individually or simultaneously with feeds. This enables fast machining without having to realign the workpiece.

Production of chamfers, cutouts/openings and threads

Milling metal sheets

Various tools are available for milling in a changer magazine, which can be exchanged automatically if necessary. This enables speedy machining without lengthy retooling times. With these tools we can make bearing seats, chamfers, fits, cutouts and openings and high-precision threads. The milling is carried out by tools that are fitted with indexable inserts. These inserts are made of extremely resistant steels, which have far higher hardnesses than the workpieces to be machined. The indexable inserts remove material from the surface of the sheet metal part by fast rotation. The required shaped element is therefore produced chip for chip. For this reason, this process is also called chip removal.

Milling tools

description milling toolFor each application there are special milling tools which can be used as and when needed. The tooling design is very similar. The heart of each milling tool is the indexable inserts (1) made of extremely resistant steel.

These inserts have a different angle on each side and can be adjusted to the required angle by simply turning them. The indexable inserts are mounted directly on the milling head (2), which in turn is connected to the milling machines by means of the tool holder (3). The tool shown in the photo is suitable for deburring sharp-edged sheet metal parts and for milling chamfers with different angles.

Milling holes

Holes are often made by us by Laser cutting. However, there is a rule of thumb that states that the diameter must be at least equal to the material thickness. In exceptional cases and very good material quality, the actual radius can be slightly smaller than this radius. The large amount of heat produced by the laser beam causes scaling on the underside of the metal sheet if the radii are too small. Time-consuming rework is then necessary to remove the scale. The material driven out to make the hole can also deposit on the edge of the hole.

If the material is highly reflective, the laser cannot cut through the material and is reflected back instead. In this case holes have to be drilled. This can be done up to a diameter of 32 mm. Larger holes are then made by milling.

Magnetic bed

magnetic bedOur milling machine is equipped with a modern magnetic bed. This means that workpieces do not have to be fixed with holding fixtures or vices. The metal part is solely fixed by the magnetic bed. This magnetic bed is equipped with numerous electromagnets, which are energised on startup and therefore generate a strong magnetic field.

Use of this magnetic bed makes milling easier in many ways. On the one hand, time-consuming alignment and fixing is no longer necessary. The machining centre has several sensors, with which the milling machine can determine the precise position of the workpiece.

It is then fixed solely by the magnetic field, whereby all sides of the part are freely accessible and that facilitates milling. A disadvantage of the magnetic bed is the height of the bed. As electromagnets use up a certain height, the maximum machining height for milling is reduced by 70 mm.

Apart from this small disadvantage, we benefit from an extremely short setup time. The workpiece is placed on the magnetic bed. Sensors register its precise position and the machining centre can cut or mill out the programmed elements. Machining metal sheets couldn’t be faster!

CAM system

We use a CAM system to program the products to be produced. CAM means Computer Aided Manufacturing and enables three-dimensional development of workpieces at the computer. With this system we can produce quickly and cost-effectively. Thanks to the computer controls, very high accuracies are achieved by milling. Our customers benefit from short setup times and fast production.

Just in time

Once a workpiece has been programmed by our CNC department, it can be called up again within seconds and passed on for milling. In case of regular requirements or wearing parts, a simple purchase order is sufficient and the parts can be made immediately and delivered as required.

Just in time has many and large advantages. It removes the need for organisational and financial expenditure on keeping stocks. Only the stock needed for smooth operations is kept. That saves space and creates order. Another advantage lies in the lower acquisition costs, as it is not necessary to set up a large stock. This means that no money is tied up in unnecessary stocks.

How does chamfer milling work?

One method of making Chamfers is milling. Virtually any chamfer angle can be made by rotating the milling head without causing knurling to occur at the workpiece edges. This is especially interesting for workpieces that are not welded.

With our machining centre we can mill chamfers with all angles. We have suitable tools for several standard angles, which reduces the machining time considerably. Other chamfers are also no problem. They are milled gradually.

In the case of stepped chamfers, choosing the correct milling head is decisive for quality. It is necessary to consider for what the chamfer is needed and what degree of position is required. If it is only the angle that is important and the surface is secondary, the steps can be made somewhat wider.

This saves machining time. In the case of chamfers that need both a precise angle and an absolutely smooth surface, the stepping can be made so fine that no machining pattern remains.

How does deburring by milling chamfers work?

milling chamfersWorkpieces can have untidy and sharp edges after machining. Such burrs are a safety risk and also hinder use or further processing. To remove this defect, we mill a sloped or chamfered surface at the material edges.

Chamfers can have different angle inclinations. We mill standard chamfers with 30°, 45° or 60°. This improves the visual appearance of the workpiece and removes the risk of injuries. Chamfers are helpful when jointing several components, as they help to join the sheet metal parts at the correct angle.

How are fits (clearances) milled?

Fits can be made using different production methods, depending on their requirements. When choosing the production method the tolerable clearance between the hole and shaft is decisive. If fits are required in the agricultural sector, a larger clearance or allowance is possible as for fits in vehicle and engine construction. Very precise fits can be made by drilling, which have a roughness depth (peak to valley height) of 16 to 250 micrometres.

Milling is a far more precise production process and can achieve roughness depths of up to 1.6 micrometres. With our milling we can make very high-quality fits, which satisfy the highest standards.

Can welds be prepared by milling?

chamfersIn classic weld preparation we mill a chamfer at the material edges. The milling produces very clean surfaces, which can then be welded together extremely well.
The chamfered angle helps the welder to join the assemblies. Variable chamfer angles and surface sizes can be produced depending on the customer’s wishes.
Milling chamfers is a relatively expensive method of weld preparation. In order to keep the unit price low, we use a preparation machine especially purchased for this task.

How are threads milled?

With our machining centre we can make high-precision Threads in components. One advantage is that different size threads can be made with the same tool. As the milling takes place with little pressure, threads can also be made in thinner workpieces.

We can basically mill threads of all sizes. Our technicians will be pleased to advise you on which maximum thread sizes are possible in relation to the workpiece size and still have a high mechanical load capacity.