The Development of a New Course The Development of a New Course in Nontraditional Machiningin Nontraditional Machining

Kuen-Ming Shu* and Kuen-Ming Shu* and Shan-ying PanShan-ying Pan****

*National Formosa University, Huwei, Yunlin, Taiwan, R.O.C*National Formosa University, Huwei, Yunlin, Taiwan, R.O.C

**** National Tsing Hua University, Hsinchu, Taiwan, R.O.CNational Tsing Hua University, Hsinchu, Taiwan, R.O.C

IntroductionIntroduction

• Nontraditional machining course was initiated in the MMED at NFU in Taiwan in 1998.

• 2 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 To increase the student’s learning experience, it is necessary that learning experience, it is necessary that learning process should involve more than the process should involve more than the usual learning by doing approach.usual learning by doing approach.

• In order to bridge the gap between In order to bridge the gap between

theory and practice, we establish this theory and practice, we establish this new course called “new course called “Nontraditional Nontraditional machining technology and practicemachining technology and practice””. .

Nontraditional machiningNontraditional 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 COURSELECTURE COURSE

• There are literally dozens of nontraditional There are literally dozens of nontraditional machining processes, most of which are machining processes, most of which are unique in their range of applications. unique in their range of applications.

• The nontraditional processes are often The nontraditional processes are often classified according to principal form of classified according to principal form of energy used to effect material removal.energy used to effect material removal.

Four typesFour types of nontraditional machining of nontraditional machining

Type Process Symbol

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 machining CHM

PProblems with traditional instructionroblems with traditional instruction

• Students didn't learn skillsStudents didn't learn skills

• Students are not given the opportunity to Students are not given the opportunity to pursue new knowledge in the service of pursue new knowledge in the service of achieving intrinsically motivating goals.achieving intrinsically motivating goals.

• The knowledge or skills is divorced from real The knowledge or skills is divorced from real lifelife

New course descriptionNew 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 coursesThe chose practice courses

CHM

USM

AJM

ECM

EDM

LBM

Practice

course

EDM processesEDM processes

1.1. Electrode fabricationElectrode fabrication

2.2. Set EDM parametersSet EDM parameters

3.3. EDMEDM

4.4. Surface polishingSurface polishing

Guide rod and Engraving cutting tool grindingGuide rod and Engraving cutting tool grinding

33D engravingD engraving

The products of 3D engravingThe products of 3D engraving

Electrical discharge machiningElectrical discharge machining（（ EDMEDM ））

• 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 EDMThe products of EDM

Electrochemical machiningElectrochemical machining（（ ECMECM ））

• Remove or plate metal Remove or plate metal from an electrically from an electrically conductive workpiece by conductive workpiece by anodic dissolution or anodic dissolution or cathode reduction, in cathode reduction, in which the shape of the which the shape of the workpiece is obtained.workpiece is obtained.

The products of ECMThe products of ECM

Ultrasonic machiningUltrasonic machining

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

The products of USMThe products of USM

Abrasive jet machiningAbrasive jet machining

• A material removal process A material removal process that results from the action that results from the action of a high-velocity stream of of a high-velocity stream of gas containing small gas containing small

abrasive particles.abrasive particles.

The products of AJMThe products of AJM

Laser beam machiningLaser beam machining

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

The products of LBMThe products of LBM

Work sheetWork sheetN0.N0. TermTerm ProcessesProcesses

11 2D AJM2D AJM

1 .Prepare a plate mirror.1 .Prepare a plate mirror.

2. Paste a layer of tape as maskant.2. Paste a layer of tape as maskant.

3. Engrave a pattern on tape.3. Engrave a pattern on tape.

4. Tear off the unnecessary tape.AJM the mirror that isn’t protected by tape. 4. Tear off the unnecessary tape.AJM the mirror that isn’t protected by tape.

22 3D AJM3D AJM

1. Prepare a glass or ceramic bottle.1. Prepare a glass or ceramic bottle.

2. Paste a layer of tape as maskant.2. Paste a layer of tape as maskant.

3. Engrave a pattern on tape.3. Engrave a pattern on tape.

4. Tear off the unnecessary tape.4. Tear off the unnecessary tape.

5. AJM the mirror that isn’t protected by tape.5. AJM the mirror that isn’t protected by tape.

33 3D pattern3D pattern1. Prepare a piece of wood plate or acrylics plate.1. Prepare a piece of wood plate or acrylics plate.

2. Get a half pattern with draft.2. Get a half pattern with draft.

3. Stick the plate and the pattern.3. Stick the plate and the pattern.

44 Guide rod grindingGuide rod grinding1. Get a Φ6mm high speed steel rod1. Get a Φ6mm high speed steel rod

2. Grind this rod by grinding machine into ball end.2. Grind this rod by grinding machine into ball end.

55 Engraving cutting tool Engraving cutting tool grindinggrinding

1. 1. Get a Φ6mm high speed steel rod.Get a Φ6mm high speed steel rod.

2. Grind this rod by grinding machine into cutting edge.2. Grind this rod by grinding machine into cutting edge.

66 3D engraving3D engraving1. Get a soap and fix on engraving machining.1. Get a soap and fix on engraving machining.

2. Set guide rod, engraving cutting tool, and 3D pattern.2. Set guide rod, engraving cutting tool, and 3D pattern.

3. Engrave a replica on soap.3. Engrave a replica on soap.

Worksheet Worksheet (Cont.)(Cont.)

N0.N0. TermTerm ProcessesProcesses

77 EDM graphite electrodeEDM graphite electrode1. Get a used AAA battery and draw graphite central rod out.1. Get a used AAA battery and draw graphite central rod out.

2. Engrave the end of graphite central rod.2. Engrave the end of graphite central rod.

88 EDMEDM1. Get a piece of steel plate and fix it on EDM machine.1. Get a piece of steel plate and fix it on EDM machine.

2. Set the graphite electrode and progress EDM. 2. Set the graphite electrode and progress EDM.

99 LBMLBM1. Get a piece of wood or acrylic and fix on laser machine.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.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. 3. Control the laser machine to engrave this design on wood or acrylic surface.

1010 ECMECM1. Prepare a Cu tube as cathode, a steel block as anode, and NaCl solution as electrolyte bath.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 2. The electrolyte bath flows rapidly between the two poles to carry off the dissolution material and form a concave hole.a concave hole.

1111 USMUSM1. Get two pieces of plastic plate.1. Get two pieces of plastic plate.

2. Set the parameters of USM.2. Set the parameters of USM.

3. Progress ultrasonic welding.3. Progress ultrasonic welding.

1212 CHMCHM

1. Get a photo resist coated circuit board.1. Get a photo resist coated circuit board.

2. Draw a design on transparency as mask2. Draw a design on transparency as mask

3. Expose on exposure unit.3. Expose on exposure unit.

4. Develop resist.4. Develop resist.

5. Etch in etching tank.5. Etch in etching tank.

Instruction methodsInstruction methods

• For the first week, all the equipments to For the first week, all the equipments to perform the experiments were introduced.perform the experiments were introduced.

• The following weeks, the students were The following weeks, the students were

asked to prepare materials, design projects, asked to prepare materials, design projects, implement projects, and evaluate and implement projects, and evaluate and demonstrate their products in teams. demonstrate their products in teams.

Evaluate and demonstrate products Evaluate and demonstrate products in teamsin teams

Evaluation sheetEvaluation sheet

Evaluate resultsEvaluate 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.

84

34

1 1 00

10

20

30

40

50

60

70

80

90

Persons

Very

satisfying

Satisfying Average Unsatisfying Very

unsatisfying

The intention of students to take similar courseThe intention of students to take similar course

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

111

6 30

20

40

60

80

100

120

Persons

Take It depends No more take

ConclusionsConclusions

• 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.

ENDEND

Thanks for your attentionThanks for your attention