Archives for July 2017

• For models with dimension of up to 254 x 254 x 305 mm, with 178 μm layer thickness and positioning accuracy of 240 μm.

• 2 heads (building and support material).

• FDM (Fused Deposition Modelling) technology (heating and extrusion of thermoplastics); material: ABSplus (acrylonitrile butadiene styrene).

• Import of STL (Standard Tessellation Language) 3D models from CAD + SW for printing process optimization (including support structure optimization).

• An additional 3D printer (Stratasys Connex 500), capable of using up to 14 different materials with different stiffness properties, available at the Faculty of Civil Engineering on same U. of Rijeka campus → PolyJet technology: similar to desktop inkjet printers, with photo polymer material hardened under UV light; printing resolution down to 16 μm.

FDM process:

• Advantages: laser not needed, fast and secure procedure, lower power consumption, unnecessary cooling and ventilation, simple usage, low investment, low maintenance costs, small size (additional room not needed), warping effect minimised.

• Disadvantages: surface can be rough and models can have a certain porosity, model functionality is limited by the used material, in many cases the support structure has to be used, additional mechanical processing needed, lines between layers can physically be seen, hardness of the product is lower in the direction of the printed layers, oscillations in temperature during the printing process can lead to delamination of the product; upon warming, melting and solidification processes, ABS can shrink up to few %.

Examples of 3D printed structures:

 

Structured Light Technology: The distance and the angle of the camera with respect to the projector are known, i.e. distortion of the reflected light pattern (fringes) depends on object’s geometry. Projector + camera + calibration panels + rotating table.

• 500 mm scanning area,

• resolution/accuracy 1‰ of the object size,

• includes SW environment,

• mobile with tripod,

  enables exporting data to formats compatible with standard CAD SW (e.g. STL).

Examples of measured 3D structures – dental casts:

 

Haas Office series machine tools characterized by small dimensions as well as outstanding performances and exceptional benefits for the end users; include user-friendly interface, HAAS/Fanuc control unit as well as technical support from the Croatian representative company Teximp d.o.o.

Haas Office OM-2A milling machine

• dimensions within an 1.7 x 0.84 x 1.9 m envelope,

• enables a 5-axes machining with up to 20 automatically interchangeable tools,

• machining volume 305 x 254 x 305 mm,

• 1 µm displacement resolution; spindle velocity of up to 30’000 rpm and 3.7 kW power.

 

Haas Office OL-1 lathe

• dimensions within an 1.3 x 0.84 x 1.8 m envelope,

• 4-axes, 12 tools,

• turning diameter of up to 250 mm,

• 1µm displacement resolution,

• spindle velocity of up to 6’000 rpm and power of up to 5.6 kW.

 

 

• Heated (up to 70 °C) prewash with oil separation

• ultrasound (10 PZT inverters, 40 kHz, 500 W continuous and 2 kW peak power) 45 l heated stainless steel bath for cleaning with a “soft” (pH 9.9) detergent and with filtering of media (particles’ separation)

• 2 baths for rinsing in demineralized water with heating (1.2 kW, 30 … 80 °C)

• drying with hot air (up to 300 °C).