The Development of a New Course in Nontraditional Machining Kuen-Ming Shu* and Shan-ying Pan ** *National Formosa University, Huwei, Yunlin, Taiwan, R.O.C ** National Tsing Hua University, Hsinchu, Taiwan, R.O.C

Introduction Nontraditional machining course was initiated in the MMED at NFU in Taiwan in credits with a 2hrs lecture per week. It is developed to offer students with a knowledge-oriented nontraditional machining technology.

To increase the student’s learning experience, it is necessary that learning process should involve more than the usual learning by doing approach. To increase the student’s learning experience, it is necessary that learning process should involve more than the usual learning by doing approach. In order to bridge the gap between theory and practice, we establish this new course called “Nontraditional machining technology and practice”. In order to bridge the gap between theory and practice, we establish this new course called “Nontraditional machining technology and practice”.

Nontraditional machining Nontraditional machining is a group of processes involving mechanical, thermal, electrical or chemical energy (or combinations of these energies). They do not use a sharp cutting tool in the conventional sense.

LECTURE COURSE There are literally dozens of nontraditional machining processes, most of which are unique in their range of applications. There are literally dozens of nontraditional machining processes, most of which are unique in their range of applications. The nontraditional processes are often classified according to principal form of energy used to effect material removal. The nontraditional processes are often classified according to principal form of energy used to effect material removal.

Four types of nontraditional machining Type ProcessSymbol Mechanical Water-jet machining Abrasive-jet machining Ultrasonic machining WJM AJM USM Electrical Electrical chemical machining Electron beam machining ECM EBM Thermal Electrical discharge machining Laser beam machining Plasma arc machining Ion beam machining EDM LBM PAM I BM Chemical Chemical machiningCHM

Problems with traditional instruction Problems with traditional instruction Students didn't learn skills Students didn't learn skills Students are not given the opportunity to pursue new knowledge in the service of achieving intrinsically motivating goals. Students are not given the opportunity to pursue new knowledge in the service of achieving intrinsically motivating goals. The knowledge or skills is divorced from real life The knowledge or skills is divorced from real life

New course description We developed a practice-based course for teaching and learning. It has 1 hr lecture and two hrs of workshop experiments per week for 18 weeks.

The chose practice courses Practice course LBMEDMECMAJMUSMCHM

EDM processes 1. Electrode fabrication 2. Set EDM parameters 3. EDM 4. Surface polishing

Guide rod and Engraving cutting tool grinding

3D engraving

The products of 3D engraving

Electrical discharge machining （ EDM ） Remove metal by a series of discrete electrical discharges (sparks) that cause localized temperatures high enough to melt or vaporize the metal in the immediate vicinity of the discharge.

The products of EDM

Electrochemical machining （ ECM ） Remove or plate metal from an electrically conductive workpiece by anodic dissolution or cathode reduction, in which the shape of the workpiece is obtained. Remove or plate metal from an electrically conductive workpiece by anodic dissolution or cathode reduction, in which the shape of the workpiece is obtained.

The products of ECM

Ultrasonic machining A tool vibrating at low amplitude and high frequency to weld material, or abrasives contained in a slurry are driven by tool at high velocity against the work. A tool vibrating at low amplitude and high frequency to weld material, or abrasives contained in a slurry are driven by tool at high velocity against the work.

The products of USM

Abrasive jet machining A material removal process that results from the action of a high-velocity stream of gas containing small abrasive particles. A material removal process that results from the action of a high-velocity stream of gas containing small abrasive particles.

The products of AJM

Laser beam machining The source of energy is a laser, which focuses optical energy on the surface of the workpiece. The highly focused, high-density energy melts and evaporates portions of the workpiece in a controlled manner. The source of energy is a laser, which focuses optical energy on the surface of the workpiece. The highly focused, high-density energy melts and evaporates portions of the workpiece in a controlled manner.

The products of LBM

Work sheet N0.TermProcesses 1 2D AJM 1.Prepare a plate mirror. 2. Paste a layer of tape as maskant. 3. Engrave a pattern on tape. 4. Tear off the unnecessary tape.AJM the mirror that isn ’ t protected by tape. 2 3D AJM 1. Prepare a glass or ceramic bottle. 2. Paste a layer of tape as maskant. 3. Engrave a pattern on tape. 4. Tear off the unnecessary tape. 5. AJM the mirror that isn ’ t protected by tape. 3 3D pattern 1. Prepare a piece of wood plate or acrylics plate. 2. Get a half pattern with draft. 3. Stick the plate and the pattern. 4 Guide rod grinding 1. Get a Φ6mm high speed steel rod 2. Grind this rod by grinding machine into ball end. 5 Engraving cutting tool grinding 1. Get a Φ6mm high speed steel rod. 2. Grind this rod by grinding machine into cutting edge. 6 3D engraving 1. Get a soap and fix on engraving machining. 2. Set guide rod, engraving cutting tool, and 3D pattern. 3. Engrave a replica on soap.

Worksheet (Cont.) N0.TermProcesses 7 EDM graphite electrode 1. Get a used AAA battery and draw graphite central rod out. 2. Engrave the end of graphite central rod. 8EDM 1. Get a piece of steel plate and fix it on EDM machine. 2. Set the graphite electrode and progress EDM. 9LBM 1. Get a piece of wood or acrylic and fix on laser machine. 2. Use CoreDraw 9 software to create a design on personal computer. 3. Control the laser machine to engrave this design on wood or acrylic surface. 10ECM 1. Prepare a Cu tube as cathode, a steel block as anode, and NaCl solution as electrolyte bath. 2. The electrolyte bath flows rapidly between the two poles to carry off the dissolution material and form a concave hole. 11USM 1. Get two pieces of plastic plate. 2. Set the parameters of USM. 3. Progress ultrasonic welding. 12CHM 1. Get a photo resist coated circuit board. 2. Draw a design on transparency as mask 3. Expose on exposure unit. 4. Develop resist. 5. Etch in etching tank.

Instruction methods For the first week, all the equipments to perform the experiments were introduced. For the first week, all the equipments to perform the experiments were introduced. The following weeks, the students were asked to prepare materials, design projects, implement projects, and evaluate and demonstrate their products in teams. The following weeks, the students were asked to prepare materials, design projects, implement projects, and evaluate and demonstrate their products in teams.

Evaluate and demonstrate products in teams

Evaluation sheet

Evaluate results 84 students (i.e. 70%) were very satisfied after took this course, while 34students (i.e. 28%) were satisfying. Only 1 student choice the “Average” or “unsatisfying” item respectively. It seems that almost all students enjoy this new developed course.

The intention of students to take similar course It is shown that 111 students (i.e. 93%) are very interested in this new developed course and claimed that they would take the similar course if they were provided It is shown that 111 students (i.e. 93%) are very interested in this new developed course and claimed that they would take the similar course if they were provided

Conclusions In order to promote traditional instructing methods, we have developed of a new course on nontraditional machining. Both contents of lecture and practice are demonstrated in this new course. The worksheet for practice experiments and evaluate questionnaire sheet were also developed. The new course was developed successfully.

END Thanks for your attention