CNC Machining - Texas A&M University · The Virtual Training Environment for CNC Machining ......

Flight Simulator TechnologyThe Virtual Training Environment for CNC Machiningcombines powerful “flight-simulator” technology with aflexible Internet-based learning content managementsystem to deliver a truly innovative learning experience.

Major BenefitsCost-effective and safe24/7 access at your convenienceTrack and measure learner progressReduce risk to people and equipmentIncrease control panel training contact-timeLearn with virtual controls and 3D machines

Mimic Reality• Virtual mills and lathes

• Industrial control panels

• Edit, load, run and save NC programs

• Set tool and work offsets

• Touch probes

• Stock material removal

• Canned cycles

• Control alarmsLearning Productivity ToolUnlimited access to train and rehearsein the Virtual Training Environment forCNC machining enables learners todevelop greater confidence andproficiency prior to performing actualprocedures and operating equipment.

Learn at Your Convenience!Learn CNC machine setup and program-ming with popular control panels forHaas Machine Tools.

Real-time material removal

Mill and lathe touch probes

Lathe applicationsPopular control panels

Simulated 3D machine models

Virtual Training Environment

CNC Machining

• Robotic simulation

• Learning content management system

• Online evaluation tools

• Content development

• Onsite training

• CNC programming

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Mill and Lathe CNC online courses provide the learner with comprehensivelearning content, interactive exercises and virtual CNC panels and 3D machines.Depending on the course selected learning modules may include:

Online Learning Courses and Virtual 3D CNC Machine

Color Manuals, Exercises and Projects

Mill CNC Programming and Applied Mathematics Level 2This intermediate to expert level manual provides much moreadvanced application of codes, programming, and use of cannedcycles. The content and sample programs provided cover a broadrange of CNC programming requirements. Advanced mathematicsand formulas including applied shop floor trigonometry andgeometry are used.

An introduction to codes and programming, this manual isdesigned for beginner to intermediate level Lathe CNC operatorsand programmers. The content and sample programs providedcover a broad range of CNC programming requirements. Basicmathematics and formulas are used.

Lathe CNC Programming Level 1

An introduction to codes and programming, this manual isdesigned for beginner to intermediate level Mill CNC operatorsand programmers. The content and sample programs providedcover a broad range of CNC programming requirements. Basicmathematics and formulas are used.

Mill CNC Programming Level 1

SetupMachine Motion DescriptionCNC Panel InterfaceMachine Start-upManual OperationsJob SetupEdit CapabilitiesProgram EntryProgram RunProgrammingCodes and ProgramsProgram StructureCartesian Coordinates SystemCutter CompensationTool Nose Radius CompensationCircular InterpolationHole ManufacturingProgramming Labs

Interactive online courses

Immersive Engineering, Inc. and Powered by Immerse2learn.com are registered trademarks. All product names used herein are for identification purposes onlyand may be trademarks of their respective owners. Immersive Engineering, Inc. disclaims any and all rights in those marks. Copyright Immersive Engineering, Inc.

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Prepare Students for Today’s Shop Environment bySeamlessly Linking CAM Programming to CNC Machining

Lansing Community College

At Michigan’s Lansing Community College(LCC) Mark McComb, CAD/CAM Instructor andJeff Tarr, CNC Machining Instructor teach thetwo ends of the art to part manufacturingprocess. McComb focuses on product designand cutter path creation. Tarr is responsiblefor developing flawless NC programs, ensuringproductive and safe CNC machine operation,and producing high quality parts. The two menuse the Internet-based, Virtual TrainingEnvironment for CNC (VTE-CNC), poweredby Immerse2Learn.com to create acontinuous line of teaching.Increased ProductivityMcComb and Tarr credit the Internet-based Learning System with dramaticallyboosting their productivity. “With VTE-CNC,” says McComb, “I can teach the samematerial in 96 contact hours that oncerequired 288 hours. We’ve consolidatedthree courses into one because we’remore time-efficient.”

Students spend much lesstime waiting to use machines.Students use the machines moreproductively when they’re on them.Tightly link CAD/CAM to CNCmachining instruction, so studentscan transition fast from automated tomanual programming, CNC controlinterface, and general machiningoperations.Learning can be customized tomeet changing industry demand.

“Our student’s basic instinct is to getthrough our program, find a job, and startearning a good quality of life,” McComb states.This won’t be hard, because there are morethan 200 machinist jobs vacant in the five-county area around Lansing, Michigan. Somestudents receive offers prior to graduation.Total Training SolutionVTE-CNC’s complete system consists ofsoftware with tutorials and quizzes and virtualCNC control panel and 3D machining centersthat help teach machine tool operation.Students can access the materials 7/24 on linein school or at home, learn at their own pace,

and back up to review or repeat as much asthey wish.“With VTE-CNC, students come to classenthusiastic and better prepared,” says Tarr,“The virtual training environment is moreinteractive than a textbook. ”Students can readabout the subject, view an operation oninteractive video, play it forwards andbackwards, take it apart, and see how it works.

“Today’s young people are computer oriented,”he continues. “They work comfortably with thefast-paced VTE-CNC materials, which providea tremendous amount of information. I’ve hadinstructors tell me that they taught more inthirty minutes to students prepared with VTE-CNC than they did in three contact hoursbefore using the virtual training environment.”VTE-CNC has tools that allow instructors tocustomize the system to meet a variety oftraining needs. When students required moreinformation about Cartesian Coordinates, the

“With VTE-CNC,

students come to

class enthusiastic

and better prepared.

In the first year, we

realized our return

on investment.”

- Jeff Tarr

Mark McComb, Computer AidedDesign and Manufacturing Instructor

Egg design and machine project: threading process.Simulated with virtual CNC panel and 3D machines in VTE-CNC.

Egg design and machine project: contour roughing and finishing.Simulated with virtual CNC panel and 3D machines in VTE-CNC.

From Art to PartA Continuous Line of Teaching

Prepare Students for Today’s Shop Environment bySeamlessly Linking CAM Programming to CNC Machining

Lansing Community CollegeFrom Art to PartA Continuous Line of Teaching

3D spatial system, McComb inserted a PowerPoint presentation as an additional “learningresource.” VTE-CNC also lets Tarr pick andchoose the learning modules he wants to use.“If I’m teaching lathe,” he states, “I can activatethe appropriate learning modules to deliver acontrolled and focused lathe class.”250% ThroughputIncrease with Virtual TrainingStudents use VTE-CNC to edit the CAD/CAMgenerated or manually written part programs.“If the code they’ve written will crash themachining center, the software tells them,” saysTarr, “and they correct it in a truly virtualenvironment.” Once the program is visualizedin a 3D interactive environment, students moveto a machining center and make parts with it.In the past, students edited programs on amachine tool and sometimes monopolized itfor an entire class period while others had tolearn by observing. “I wasted valuableinstruction time managing student access andanswering the same CNC operation questionsfor each individual,” says Tarr.

LCC has five mills and five lathes in itsadvanced manufacturing program, saysMcComb. “Before we had VTE-CNC, we couldteach ten students at once on those machines,but nowadays our capacity is 25. Based on ourincreased throughput, I guess you’d say thepayback is 2.5 to 1.”Once they have demonstrated that they areready in VTE-CNC, up to ten students can workon the mills and lathes while the others learnwith virtual CNC panels and 3D machines. VTE-CNC reproduces the controls of a Haas CNCmachine and the steps it takes to make a part.Students access it on line, practice machiningin a virtual environment, and even make avirtual part before they work with a realmachine tool. McComb can project any imagefrom VTE-CNC in class, so a roomful ofstudents can observe a virtual machine at workinstead of crowding around a real one. Virtualpreparation means more self-confidentstudents, McComb reports. Machine tools canbe frightening to a beginner, because theywork so fast and make chips and noise.Students who have worked on VTE-CNC virtualcontrol panels and machines know what thecontrols look like and are better prepared foreverything that will happen in the real world.Local manufacturers need advanced CNCtraining for new hires and current employeeswho wish to upgrade their skills, but industrywants to keep its machines—and its people—working. This has created an opportunity forLCC. “We use our online curriculum and VTE-CNC for the first level of training,” saysMcComb, “and can deliver custom instructor-led training.” Once trainees complete theirvirtual preparation, they get hands-onexperience on LCC’s machines—or on the job.“In the first year, we realized our return oninvestment with the VTE-CNC training system.”Says Tarr. “Immerse2Learn.com has alwaysbeen very responsive to our product supportneeds.”

“Based on

the increased

throughput...

our payback

is 2.5 to 1.”

- Mark McComb

After proving their knowledge in VTE-CNC, some of Mark McComb andJeff Tarrs’ students are ready to advance to real CNC panels and machines.


“Students run the

virtual CNC panels

and 3D machines

anytime and

anywhere.”

- Gary Walters

Online Training System Combines Internet withHands-on Instruction to Produce Skilled Machinists

Macomb Community College

Gary Walters, Professor of AdvancedTechnology Applied Processes

In just thirty credit-hours—two per week for15 weeks—Macomb Community College,Warren, Michigan, can teach a completebeginner how to program and operate a CNCmachining center—and much more. Macomb’ssecret is the turnkey Virtual TrainingEnvironment for CNC Machining (VTE-CNC),powered by Immerse2Learn.com. VTE-CNCcombines learning content management;virtual CNC mill and lathe panel and 3D virtualmachines; and interactive graphical learningcontent.“Along the journey to a 62 credit hour AssociateDegree of Applied Science,” says Gary Walters,Professor of Advanced Technology AppliedProcesses at Macomb, “students can earn CNCMachinist and CAM Technologist certificates.They find it’s easier to learn with VTE-CNC—and they keep coming back for more.

Combination Technologies“Along with CAD/CAM and CNC, weteachhow to get the most out of themanufacturing process by utilizingvarying levels of automation, such aslasers and probes to define fixture andtool length offsets, magnetic tables,80,000 RPM spindles, and state of theart cutting tools,” Walters continues. Hewants graduates to feel confident thatthey can perform a variety of functionsfor a Tier 2 or Tier 3 employer. Macomb’sflexible class schedules and onlinecapabilities mean that it can provide ondemand training to small and mediumsized job shops that want to remainglobally competitive. These shops useVTE-CNC to introduce new technology tooperators or upgrade operator skills inCNC, EDM, rapid prototyping, reverseengineering, and laser. VTE-CNC scalableprogram makes this happen fast without a biginvestment.“It’s a combination of technologies that allowus to machine at high speeds and feeds, suchas 300 to 400 IPM for tool steels and 1,000+IPM for softer materials such as aluminum,”Walters explains. “The machine can’t do italone, nor can the program or the cutting tool.”He’s excited to provide this level of technologytraining to beginners and experienced peoplealike.

Macomb’s facility—a Haas Technical EducationCenter—is one of several around the US. HaasAutomation, the world’s largest CNC machinetool builder, partnered with the collegethrough the Haas Technical Education Programand the local Haas factory outlet. A keymember of this winning team isImmerse2Learn.com.

Learn by Doing“The best way to learn CNC machinetechnology is to actually use it!” Says Walters.All registered students get a personal login,which allows them to run the virtual CNCpanels and 3D virtual machines—anytime andanywhere. Working at their own pace andrepeating material as often as needed,students learn basic tool movements andmachine motion; tool response to controllercommands; canned-cycle concepts like peckdrilling, tapping, circular and linear motion;

cutter and tool length compensation; and workoffset procedures complete with probing.Students also learn how to create, run, editand save programs. They can manuallyprogram M&G code, and can load and saveNC programs and offsets. VTE-CNC combinesvirtual, 3D, interactive industrial machines;popular industrial CNC panels; and dynamicCNC mill and lathe curriculum and assessment.“Plotting out coordinates is the tough part ofprogramming and students must learn it first,”Walters explains. “In VTE-CNC, they learn it

Students go from Virtual Machiningto Cutting Metal at Internet Speed

Red electric guitar is the final product from an art-to-part process by reverseengineering, CAD/CAM, and high speed machining on Haas machining centers.

Online Training System Combines Internet withHands-on Instruction to Produce Skilled Machinists

Macomb Community CollegeStudents go from Virtual Machiningto Cutting Metal at Internet Speed

quicker because it’s taught through games.Next, they write code, which is the easy part.”Steady progress keeps them motivated and theyperform better in class.

That’s not all! Students make virtual parts risk-free, then come to class confident and pre-qualified to work on a real machining centerunder supervision of a teacher. Virtualpreparation makes the classroom experienceefficient and safe. In 2.5 years of teaching,Walters has seen just one end mill break.“The virtual training environment isinvaluable!” Walters states. “Quite honestly,we purchased the training system to get moredone in less time.”Now, students are able to train with VTE-CNCanytime and anywhere. Also, during lectures,I can project VTE-CNC onto a large screen, soeveryone clearly sees the control interface and3D machines. This is much better than tryingto gather 20 students around an actual controlpanel.”

The training system has all classroom lecturematerial built in for access anytime. Walterslikes the Learning Content Manager, which heuses to manage his students, set up additionalclasses, create quizzes, and develop newcourses. He recently wrote an EDM course withit and has more in the pipeline. In addition,VTE-CNC provides manuals to accompany theinteractive learning content so students havesomething to hold in their hands.Walters calls VTE-CNC a great marketing andrecruiting tool because it allows him to showoff his program visually. “It’s always been hardto describe CNC to non-manufacturingstudents,” he says, “but now I can clearly showthem CNC technology. I’ve seen it attract manythat never heard of this field. Parents see CNCand it just blows them away.”Walters uses VTE-CNC to link more closely withlocal high schools and vocational centerswhere he’s expanding the advancedmanufacturing program.VTE-CNC is helping to put manufacturing backinto classrooms that have been limited tocomputer-aided-design for years, due to spacerestrictions, liability and a shortage of qualifiedinstructors. It’s a real win-win.Return on Investment... BIG TIME!The Virtual Training Environment for CNC(VTE-CNC) delivers:

Attract and keep more students.Learning is fun, even the tough parts.Students perform better, stay motivated.All learning tools available 7/24.Students work at own paceand come to class better prepared.Students learn machine operation inrisk free virtual environment, pre-qualifybefore using real machine tools undersupervision.Teachers get more done in less time.

“We purchased

the training

system to get

more done in

less time.”

- Gary Walters

Gary Walters and Eric Lewicki, Associate degree student, CNC certificatesgraduate, and MCTEAA- Macomb County outstanding student award recipient.


“There will

probably be a

lot of programs

that benefit

from this

technology.”

-Ray Niergarth

Students Access Virtual Machining CentersOnline 24/7, Before Advancing to the Real Deal!

Northwestern Michigan CollegeTeachers and Students Do More In LessTime with Online Virtual CNC Training

In just over a year, the Virtual TrainingEnvironment for CNC (VTE-CNC), powered byImmerse2Learn.com has made theManufacturing Technology program moreefficient and effective at NorthwesternMichigan College (NMC) in Traverse City. RayNiergarth, Instructor in ManufacturingTechnology, credits VTE-CNC onlineaccessibility and interactive features.Northwestern Michigan College’s (NMC)Manufacturing Technology program comprisesbasic mill and lathe operations (two semesters)and CNC machining and CAM programming(two semesters). Graduates can earn aMachining Certificate or an Associate Degree.Students Work SmarterNMC uses VTE-CNC to teach actual CNCoperations in the virtual world, so that studentswork smarter in the real-world. Niergarth says,“Students develop CNC programming andsetup skills in VTE-CNC, before they are ableto work one-on-one with instructors at actualCNC machines on the shop floor.” Niergarthadds, “This training process helps make thelearning experience more productive.”

When NMC purchased a mill and lathe fromHaas Automation, it licensed VTE-CNC, whichconsists of software with tutorials and quizzes;and the virtual CNC panels and 3D machiningcenters that aide in teaching machine tooloperation. Now, students can access classmaterials 24/7 on line at home or in NMC’scomputer lab. They learn at their own pace—and can back up to repeat material as muchas needed.Teaching software can be a powerful tool whenit’s used to reinforce classroom instruction—and it helps to make everything more efficient.The Virtual Training Environment for CNC (VTE-CNC) has vivid, easily understood graphicaldemonstrations of tool movement. Thesoftware includes self-tests with immediatefeedback that helps students come to classbetter prepared.Niergarth’s classroom presentations reinforcewhat students get from VTE-CNC. “Differentpeople have different ways that they learnbetter,” he states. The combination of VTE-CNCand classroom instruction ensures that thecollege is providing the most comprehensivelearning environment available today.

Students learn how to load, modify and run NC programswith virtual CNC panels and machines, before the real-world.

Instructors and students benefit from online interactive learning content, exercises,assessments and virtual CNC panels and 3D machines that run actual M&G code programs.

With VTE-CNC, the learning material is “alwaysthe same for each class, for each student,” hecontinues. “There’s always a chance thatsomething gets overlooked or presented alittle differently in the classroom. The softwaregives everyone the same information and it’salways easy to find there.”Bottom Line—everyone works smarter.Classroom instruction and software reinforceeach other, so students learn more and learnit quicker. Instructors make better use ofclassroom time and present more material inthe same number of hours.

-Ray Niergarth

“Teaching with

the virtual CNC

panels and 3D

machines sure

beats having

everyone crowd

around one

machine”

“The instructor editing capability is definitelya benefit,” he says. The instructor’s automaticgrade book/student performance trackingfeature speeds and simplifies record keepingfor large classes, freeing Niergarth to teach.

To continually promote NMC’s ManufacturingTechnology program, Niergarth createsawareness among high school counselors withpresentations and tours to manufacturingsites. He tells them that machining haschanged over the past few years withincreasingly sophisticated technology and ahighly trained workforce.NMC shares its machine lab and equipmentwith the high school machine shop program.Younger students learn CNC operation andsetup. CNC Programming starts when theyreach college level. VTE-CNC helps here too.The software is wonderfully flexible, whichallows instructors to make selected portionsavailable to beginning students.Industry calls NMC looking for graduates. AsNiergarth tells it, auto-related manufacturingin Michigan is “slowing down or closing,” butother area manufacturers are “going strong”with products like stainless surgicalinstruments. There are plenty of openings andopportunities for graduates in northwesternMichigan’s growing manufacturing sector.Niergarth sees VTE-CNC as the coming thing.“There will probably be a lot more programsthat benefit from this technology,” he states.It could be used to teach “computer-assisteddrafting, solid modeling, programming logiccontrollers, and many other skilled trades.”

Like the Real ThingNiergarth has one Haas lathe and one Haas millin his classroom, which means that he cansupervise only two students as they workhands-on. While they wait their turn, otherstudents complete assignments with VTE-CNC’svirtual CNC panels and 3D machining centerswith graphic imagery that looks and behaveslike the real thing. Niergarth says that it’simportant to instruct students on the machineone by one to ensure safety and also becausehe can give them tips from his personalexperience. If he wants to demonstrate anoperation to the entire class, he can projectVTE-CNC virtual CNC panels and Machines atthe front of the classroom. Studentsinteractively follow along at their own computerstations. This beats having everyone crowdaround the machine.

Students Access Virtual Machining CentersOnline 24/7, Before Advancing to the Real Deal!

Northwestern Michigan CollegeTeachers and Students Do More In LessTime with Online Virtual CNC Training

Instructor, Ray

Niergarth at the controls.

Students learn CNC programming in VTE-CNC’sInternet-based virtual environment,troubleshooting as they go. The virtual CNCpanel sounds an alarm if they make an errorthat would crash a real machine. This savestime and all but eliminates the risk of costlymachine crashes. “We catch a lot of potentialproblems,” says Niergarth.There are other VTE-CNC features thatNiergarth likes. He can customize or edit testquestions in the material to fit the learning styleof students or his personal preference.

Students zoom-in and rotate around a virtualmill to review programs, before cutting actual parts.


2

HTEC Mich_13jul10.pptx

Gary SanMiguel1, Rufus Lamere2, and Wayne Hung3

1Biomedical Manufacturing Center, Athens, TX2Texas State Technical College, Waco, TX

3Texas A&M University, College Station, TX

Present atTexas HTEC Conference

Waco, TexasOct 29, 2010

Contact: [email protected]

BMC

http://engineering.tamu.edu/

3Source: (Marksberry and Jawahir, 2008)

INTRODUCTION

The cost of cutting fluids is around 17% of the machining costs of automotive components.1.2 million workers are affected by the chronic

effects produced by cutting fluids.OSHA demands tighter control on cutting fluids

(cost, maintenance, disposal, emission standards…)Propose solution: use micromist as minimum

quantity lubrication in machining

4

OBJECTIVES

1) Characterize micromist2) Apply micromist in macro/micro machining3) Identify technical issues4) Study economics of micromist

5

NSF-RET program (summer2010)

6

INVESTIGATION: setup1) Machines: Haas OM2 CNC micromill, VF1 CNC mill, and SL20 CNC lathe.2) Workpieces:

Micromachining: 12 mm (1/2 in) square bars of 316L stainless steel, CP titanium PEEK plastics, H11 tool steel, 1010 steel, 6061-T6 aluminum.Macromachining: 4140 steel bars / plates

3) ToolsMicromill: TiN un/coated WC, Ø100-1016µm (0.004-0.040 in) Microdrill: Uncoated WC Ø50-203µm (0.002-0.008 in) Macromill: TiN un/coated WC Ingersoll APKT102308R-HS insert, Ø15.8 (5/8 in)Marcroface: TiN un/coated WC Hertel TNG431 insert

4) Tool failure criteria: 50 µm (0.002 in) flank wear for microtool, 300 µm (0.012 in) for macrotool.

7

INVESTIGATION: setup5) Machining parameters:

Micromilling: 15-157 m/min (50-520 ft/min),10 µm/tooth (0.0004 in/tooth), 0.35mm (0.014 in) axial depth, 0.56 mm (0.022 in) radial depth, climb (down) side milling.Macromilling: 55-102 m/min (183-343 ft/min), 0.043-0.178 mm/tooth (0.0017-.0070 in/tooth), 1-2 mm (0.04-0.08 in) axial depth, 4.25-8.5 mm (0.017-0.333 in) radial depth, down milling on D2 tool steel.Macrofacing: max 44-80 m/min (147-265 ft/min), 0.5 mm (0.020 in) depth of cut, 0.1-0.3 mm/rev (0.004-0.006 in/rev) feedrate, constant RPM, on 4140 steel.

6) Cutting fluids: DryFlood cooling: synthetic Blasocut 2000 Universal, 5:1 mixture Micromist: UNIST Uni-MAX system, 2210EP oil, 0.022 cc/min.Use with Mistbuster500.

8

INVESTIGATION: setup

7) Measurement:Keyence LK-G82 laser system, 70µm beam, 50 kHz sampling rate, 0.2 µm resolutionOlympus STM6 measurement microscope, 0.1 µm resolutionJEOL JSM 6400 scanning electron microscopeVideo tensiometer FTA 188, 001 mN/m accuracy

8) Computer aided toolsSolidWorks, FeatureCam, and MasterCam softwareCosmos finite element software

Computer Imaging Lab

9

17

INVESTIGATION: machines

Ø3mm (1/8”) plug gage @ 10k rpm

Haas OM2 CNC micromill:5-axis capability50,000 rpm air spindle

1 µm spindle runout3 µm repeatability

Micromist2210EP oil, 0.022 cc/min30 mm @60 from z axis-45 in x-y plane

x

18

INVESTIGATION: machinesHaas VF1 CNC mill:

5-axis capability7,500 rpm spindle

25 µm spindle runout3 µm repeatability

Micromist2210EP oil, 0.022 cc/min25 mm @70 from z axis-120 in x-y plane

x

19

INVESTIGATION: machinesHaas SL20 CNC lathe:

Live tooling capability3,400 rpm spindle

3 µm repeatability

Micromist2210EP oil, 0.022 cc/min6 mm @150 from y axis-60 in x-y plane

zx

20

MICROMACHINING: tool setting

Microtool offset using laser sensor

(b)Set up for tool height z-offset

xzy

(a)Set up for edge detection on x-y plane

xy

z

21


Edge detection for tool offsets in x, y directions.

-3-2-10123

0 5 10 15 20 25Trial Number

Devia

tion

from

Mea

n (μ

m)

Laser on 5/16 inch drill Mechanical edge finder Laser on 1/8 inch plug gage

(mil)

0

-0.1

0.1X, Y settings depend on tool quality

A precision plug gage should be used

22

-15-10-5

0

51015

0 10 20 30Trial Number

Devia

tion

From

Mea

n (μ

m) paper & center drill

paper & 4-insert cutterlaser & drill on membrane


Tool height offset in z direction.

Z offset depends on tool geometry

Expect a larger z offset error than x, y offsets

0.2

0.4

-0.2

-0.4

0

(mil)

23

MACHINING: cutting fluid

1) Penetrate the boundary layer of a rapidly rotating tool,

2) Adhere to a tool surface despite centrifugal force, and

3) Wet the tool/chip interface to provide lubricating/cooling

For effective cooling/lubricating, cutting fluid must:

24

xpn = Vf t + Mα ( V0 cosθ0 - Vf ) [1 - e -(α /M) t ]

ypn = Mα V0 sinθ0 [1 - e -(α /M) t ]

Particle Trajectory

MACHINING: micromist

25

3/13

2/32

3/1]

coscos32

)cos1(.

24[)(

θθθ

πθ

+−−

=K

VP

V: volume of dropletP: diameter of dropletK: 1 for θ<900; 0 for θ>900

θ : contact angle

MACHINING: coolant wetting

26

1

2

Apparatus for Surface tension measurement1. Needle for delivering liquid droplets2. Camera


27

0

10

20

30

40

50

60

70

Water CL 1:30 2210 2210EP 2300 HD 2200

Con

tact

Ang

le (°

)

Coolant

1mm 1mm 1mm 1mm

316L Stainless Steel


29

0

10

20

30

40

50

60

70

Water KM CL2200 CL2210EP CL2300HD CL2210 RL1:15

Cont

act A

ngle

(°)

Pure Titanium


30

0

10

20

30

40

50

60

70

Water KM CL2200 CL2210EP CL2300HD CL2210 RL1:15

Cont

act A

ngle

(°)

Tungsten Carbide


31

22

6 2

h rV hh

π⎡ ⎤

= +⎢ ⎥⎣ ⎦

34

3V Rπ=

V: volume of dropleth: height of dropletR: radius of airborne dropletr: (D1+D2)/4


32

(a) Micro-droplet on a rotating tool; (b) Free body diagram of forces acting on the micro-droplet

a) b)

m: mass of dropletv: surface speed of toolR: radius of toolD: diameter of dropletσ2: surface tension of liquid

2

22 sin DmvR

σ θ σ+ = Δ


33Balance of adhesion and centrifugal force on a 2210EP microdroplet


Setup for validation of tool wetting

34(a)Mist spray setup (b) 3.175 mm 2 flute end-mill

12.7mm 2 flute end-mill (not shown)

APPROACH – OBJECTIVE # 2

RESULT: flow of micromist

Direction of flow@40 m/min

Separation of flow

Dia. 1.016mm cylinder@4000 RPM

RESULT: flow of micromist

37

MICROMACHINING: tool deflection

End deflection=17% tool diameter Bending stress= 50% tool strength

End deflection=34% tool diameter Bending stress= 100% tool strength

Spindle runout, built-up edge, uncontrolled chip, and/or cutting force deflect a microtool cyclically and cause premature tool failure.

Finite element analysis of bending stress on a micromilling tool.

38

MICROMACHINING: limit of parameters

Catastrophic failure threshold of micromilling tools.0.35mm (0.014 in) axial depth, dry , climb (down) side milling of 316L stainless steel.

0

20

40

60

80

100

0 5 10 15 20 25 30

Radia

l dep

th / C

utter

Ф(%

)

Chipload / Cutter Ф (%)

Axial depth of cut (17% cutter dia)Axial depth of cut (34% cutter dia)

Tool fracture

Tool safe

0.00

0.02

0.04

0.06

0.08

0.10

0.12

0 5 10 15 20

#4: dry#12: flood#20: mist

Time (min)

wear

(µm)

0.00

0.02

0.04

0.06

0.08

0.10

0.12

0 5 10 15 20


Time (min)

wear

(µm)

TiN-WC, V3.6m/s, F6.4mm/s, D2mm


0.00

0.02

0.04

0.06

0.08

0.10

0.12

0 5 10 15 20


39

MICROMIST: macromilling

Time (min)

wear

(µm)

0.00

0.02

0.04

0.06

0.08

0.10

0.12

0 5 10 15 20


Time (min)

wear

(µm)



40

MICROMIST: macrofacing

time(min)

0.00

0.04

0.08

0.12

0.16

0.20

0 20 40 60 80


WC on 4140, V0.9m/s max, F0.1mm/rev, D0.5mm

wear

(µm)

# passes

Dry, 75 passes

Flood, 75 passes

Mist, 75 passes

41

1) ConclusionsIn general, the dry machining produced the most flank wear vs. time. Flooding came in second, with misting obtaining the best results for tool flank wear longevity vs. time.

2) From a cost standpoint:Dry machining is the least expensive in our experiment, but of course for long term machining one would have to factor in purchasing the more expensive coated carbide or ceramic inserts, dimensional stability notwithstanding. Flooding is the most expensive, as coolant cost is high, must be checked regularly for contaminants, and must be disposed of according to environmental proceduresMisting, by far is less costly to flooding

MICROMIST: summary

Summary Continued

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3) Misting Fine pointsOil volume of Misting has little effect on the cutting performance once the minimum amount of coolant is established.It is recommended that less oil volume be used to prevent pollution of the environment and to prevent adverse health issues.

4) Submicron mist particlesContaminate other equipment.Pose potential health issues.Should be used with air cleaner unit.

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REFERENCES1) Hung N.P, Kajaria S., Chittipolu S., “Micromachining education and research at Texas A&M

University, AC2009-2503, ASEE proceedings, Texas, Jun 2009.2) Hung N.P., Chittipolu S., Kajaria S. Makarenko M., Bickston L., Williamson D., “Advances in

Micromachining of 316L Stainless Steel, SEM proceedings, Mass, Apr 2008.3) Bifano T.G., DePiero D.K., and Golini D., “Chemomechanical Effects in Ductile-Regime

Machining of Glass,” J. Precision Engineering, 1993, 15(4), 238-247.4) Bissacco G., Hansen H.N., and De Chiffre L., “Micromilling of Hardened Tool Steel for Mould

Making Applications,” Materials Processing Technology, 167: 201-207, 2005. 5) Hung N.P., Loh N.L., and Venkatesh V.C., Machining of Ceramics and Composites, ch. 10,

Marcel Dekker, 1999.6) Lee K. and Dornfelf D.A., “An experimental Study on Burr Formation in Micromilling Aluminum

and Copper,” Trans. NAMRI/SME 30, 2002.7) Sun J., Wong Y.S., Rahman M., Wang Z.G., and Neo K.S., “Effects of Coolant Supply

Methods and Cutting Conditions on Tool Life in End Milling Titanium Alloy,” Machining Science and Technology, 10:355-370, 2006.

8) Rahman M., Kumar A.S., and Salam M.U., “Evaluation of Minimal Quantities of Lubricant in End Milling,” Advanced Manufacturing Technology, 18:235-241, 2001.

9) Taniguchi N., Energy Beam Processing of Materials, Clarendon Press, 1989.

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ACKNOWLEDGEMENT

National Science Foundation (NSF award #0552885).

Mr. Dave Hayes, Haas Automation Inc.

Mr. Joe Kueter, M.A. Ford Inc.

Mr. Wally Boelkins, UNIST Inc.

Mr. Patrick Anderson, PMT Inc.

http://engineering.tamu.edu/

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