Tiberiu Dobrescu

Mathematical Models on the Closed Circuit Balancing Systems in Machine Tools

In this paper we make a comparison between the most common balancing systems used in heavy duty machine tools and especially in CNC type ones. We introduce the systems with reducing valves, pumps with pressure regulator and the systems with accumulators assembled in closed circuit. For the latter we present calculation models used during operation under adiabatic transformations (operating times of seconds) or under isothermal transformations (operating times of minutes). There are also presented applications of these models for a gantry type milling machine and an AF type machine.

Rotary Tables for Machine Tools

In this paper the authors present some theoretical and experimental research carried out during the manufacture of a rotary table for CNC machine-tools AF type. There are shown the calculation methods in static and dynamic conditions for the indexable rotary tables and also for those that operate as numerically controlled “B” axes. The calculation methods were tested by manufacturing several such tables intended for the machines belonging to AF(P)100-180 range.

Modeling, Texturing and Lighting in CAD Applications

Numerous modeling techniques exist, as well as many modeling formats. Point modeling, edge loop modeling, box modeling and paint modeling are a few of the polygon modeling techniques. Polygon proxy modeling is a variation of subdivision modeling. NURBS surfaces are used extensively in industrial design, manufacturing, and the automotive industry. Texturing and lighting transforms the dull-gray denizens of the modeling world into lifelike objects. Although texturing is nothing without good lighting, good lighting is nothing without good texturing. This article presents the process of modeling, texturing, lighting and rendering a scene in 3D. It also shows how create realistic fur, and implement studio lighting to create nice and soft shadows and highlights.