CAD / CAM - Laboratory

CAD/CAM Labor (c) FH Aachen, www.lichtographie.de

The equipment of the CAD/CAM Laboratory of the FH Aachen University of Applied Sciences allows to cover the entire CAx process chain in the production field; from model data acquisition/compilation and rapid prototyping up to the milling of components on modern 5-axis milling machines.

Practical Trainings

The CAD/CAM lab is used for the following practical trainings:

  • Basics of CAD
  • CAD/CAM

The participation in Basics of CAD is compulsory for all students. Here they learn the basic 3D work techniques required for using a CAD system. The training is performed in groups at 18 computers.

The CAD/CAM practical training comprises two parts: In the first part (CAD), the capabilities of modern CAD systems are demonstrated. Using the Inventor CAD system, students are introduced to ways of modeling and assembly modeling and much more.

In the second part of the training (CAM), students deal with the computer-aided generation of milling programs. Using the models created in the first part (CAD), they work on a simple 2D milled part before they proceed with a part of complex 3D geometry. Here they'll learn the 3D strategies required for completion, such as arbitrary stock roughing, profile and Z-level finishing, equidistant finishing, etc.

In addition to the strategies, technological issues will also be discussed, such as selecting clampings and other tools, definition of cutting data and parameters, etc. At the end of the practical training, the milling program (created by students and tested in a simulation) will be installed on the 5-axes Datron M8 milling machine and the workpiece will be produced.

Rapid Prototyping

A 3D HP printer (Design Jet Color 3D) has been part of the lab's equipment since October 2012. Rapid prototyping is an additive manufacturing technology that creates objects of ABS polymers through a sequential layering process. The generated "physical prototypes" are useful to assess the object's geometry and help select the right milling strategy for complex milling operations.

Machine Simulation

The CAD/CAM lab is provided with two 5-axis milling machines, which are used for practical trainings. Digital machine models of both machines are available and used for simulating the entire milling process before it runs on one of the real milling machines. Thus the feasibility, the functional and process reliability of the milling programs can be tested.

The lab is equipped with a virtual machine by DMG, which can be used to simulate the entire milling process running on a MAHO DMU 50eV on a computer, including such secondary processes as machine tending, tool change or clamping and measuring procedures. The real behavior of the machine can be simulated, as the simulation software allows not only to depict the workpiece, but also to control the machine. Even the manual operation and positioning of axes can be simulated via an input panel that is simular to a real machine's control panel.

The virtual machine is used

  • To enhance the process stability of complex milling operations
  • To minimize the setup time on the machine
  • To determine the exact manufacturing time
  • As training tool to familiarize operators with machine control

Manufacturing

The CAD/CAM lab is equipped with a 5-axis Datron milling machine (M8) for high-speed machining (HSM) of aluminium and plastic components which are manufactured in the CAD/CAM practical training. The HSM uses speeds up to 50.000 1/min and movement speeds and feeds up to 20 m/min. A minimum quantity lubrication is applied for the milling of aluminium components.

The DMG machining center (DMG 50 eVo linear) is used for larger components and other materials and supports, for example, 5-axis simultaneous machining. It is located in the workshop building. 

Both machines have postprocessors, which compile the machine-independently programmed travel lenghts from the CAM program into a machine-specific control program.

Data Acquisition / Quality Assurance

Since spring of 2013, the lab will be provided with a 3D printer (Steinbichler).

The 3D printer is able to recognize already existing geometries and (after having processed these data with appropriate software) to generate a digital model out of them. Another postprocessing of the raw data allows to reverse the ruled geometries and freeform surfaces to such a degree that they can be used for parametric postprocessing or modification in the CAD system.

The model size is very variable. After having produced a component, its quality (i.e. dimensional accuracy) can be tested by means of the 3D scanner. The components range from milled parts to rapid prototyping models that might have layer thicknesses within micrometers.

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