AMF

Back and forth below 2 µm exactly

A technical university produces the smallest plastic parts - prototypes of the future. During production of the moulds and tools, AMF ensures maximum flexibility with minimum tolerances. The change between two milling centres is achieved with incredible accuracy. Behind this lies a secret.

Interchangeable plate with AMF zero-point clamping systems

This creates future

The TH produces products for the medical technology sector, for dentistry and biotechnology as well as for other sectors. Thermoplastic prototypes and mini series for the smallest plastic parts are produced on three injection moulding machines before going into series production. There is a milling machine with glass scales and a high-speed spindle for producing the tools and moulds. Furthermore, there is a high-precision micromachining centre. AMF zero-point clamping systems that can be used interchangeably on both machines have optimised the set-up procedures.

Ideas become prototypes and finally series products

In order to clamp the moulds for the micromachining without long set-up times after the roughing, there were rigorous requirements for the zero-point clamping system:

  • Lowest possible installation height,
  • A base plate with 140 x 140 mm and sufficient space for larger tools,
  • An easy-to-handle system,
  • Easy changeover between both machines,
  • Repetition accuracy under 3 µm.

After preparing a comprehensive specifications sheet, AMF zero-point clamping technology is in use. A standard base plate with four AMF zero-point clamping modules K 10.2 for the milling machine. With a diameter of 112 millimetres, the module K 10.2 has a large contact surface and is resistant to lateral forces or tensile forces that are generated during machining. It has a clamping force of 25 kN and can withstand high tilting moments during the machining. This ensures high precision and dimensional accuracy even during high machining forces. Ideal for roughing.

Flat modules - yet high clamping forces

With an installation depth of just 22 millimetres the clamping module is extremely flat. This means that the base plate can also be kept very thin. The assembly on the machine table provides ample upward clearance. The modules provide a secure, vibration inhibiting fit for workpieces or interchangeable pallets that are clamped by means of (no suggestions). The reference point always remains in the centre. Temperature fluctuations as well as material expansions are compensated for by an intelligent system. The underlying technology is an AMF secret.

Seated on the base plate is an extremely flat special plate with four AMF zero-point clamping modules K 5 that has an installation height of just 23 mm. A small, powerful yet low-profile vice is screwed onto it. This is possible because the clamping modules K 5 are built very low. Nevertheless, with a clamping force of 13 kN they are very strong. And all that with a small screw-in diameter of just M45 mm. Thus, in a group of four they clamp workpieces with 52 kN. The special plate with a vice can be changed back and forth between both milling machines. An incredibly low repetition accuracy of 1.3 µm was measured with the installed Renishaw system.

Incredibly low repetition accuracy

When processes or part tolerances are even more demanding and the small milling machine with a diameter of just 40 µm is used, dimensional accuracies of 1 µm are even possible. The results of the machining are measured with a Keyence microscope, or if it has to be even more accurate, it is measured with a scanning electron microscope. This is available at the technical university.

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