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التفريز المبرمج باستخدام ملفات STL == Cnc Milling Using Stl Files
Author name:
نادية سامي حسن
Supervisor name:
ليث عبد الله محمد
General topic:
Production engineering metallurgy and materials
Specific topic:
Production Engineering
Degree:
Master
University:
University of Technology
Language:
English
University location:
Baghdad
First pages:
50T175 - p.pdf
Abstract:
تعد ملفات (STL) من الملفات المهمة في برامج الرسم والتصميم المعان بالحاسوب (CAD) والشائعة الاستخدام حاليا في النمذجة السريعة وانظمة التصنيع المعان بالحاسوب (CAM). يتناول هذا البحث اقتراح وتطوير خوارزميات لقراءة ملفات (STL) واستخلاص السمات الهندسية اللازم | Stereolithography (STL) files are considered very important files in both computer aided drawing and design (CAD) programs and are commonly used now days in both rapid prototyping and computer aided manufacturing (CAM) systems.This thesis proposes and develops algorithms to read (STL) files and extract engineering entities required in CNC milling processes. The proposed algorithms are dependent on some mathematical modeling and manipulations of the engineering model by slicing an (STL) file to many slices and then building the required algorithms to adopt these slices to generate CNC machining paths as G - Code.The proposed system in this work is divided to three parts, in the first part of this thesis an algorithm is proposed to extract engineering object entities to some proposed models based on their (STL) files using Matlab program. The proposed models include cube, cylinder, dome, cone and cavity models. In the second part of this thesis, a slicing algorithm is proposed to enable the slices along the proposed models z - axis to find and navigate the required manufacturing data. UGS CAM program was used also to generate the tool paths and to simulate the machining process and then generate NC part program of the proposed objects (G - Code). The machining process was achieved using 3 - axis CNC milling machine, at spindle speed of (700 rpm) and feed rate (60 mm/min).Finally, the third part of this thesis includes comparing results produced based on both (STL) and (UGS), to achieve the required aim by experimentally comparing both objects surface roughness and evaluate their geometrical variations.According to the experimental results, the objects produced using STL models are clearly have rough surfaces compared with the surfaces produced by UGS with average percentage of 13µm, and according to the geometrical variations experiments, CAD readings are in good agreement with experimental results and confirm the validity of the proposed approach with 4.5mm of shape error.
