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Machining Processes Laboratory

Introduction
The laboratory for research in metal machining is located in building D2. The lab was donated by ISCAR Ltd. - a world leader in producer of unique and innovative cutting tools for metalworking, including turning, grooving, milling, hole-making, boring and threading tools. It is a multinational company with representation in 50 countries.

The laboratory provides the students the essential hands-on training with modern machines and equipment, complementing their theoretical studies, and serves for research by the academic staff.
Machining is a key technology for industries in aerospace, die and mold, automotive, defense etc.


Iscar Lab Ceremony July 2007


Machining Processes Laboratory

Staff
Dr. Michael regev supervises the lab on behalf of the mechanical engineering department.  Email: michaelr@braude.ac.il
Mr. Hayyim salev is the Operator of conventional Basic machines Laboratory.

Mr. Yitzchak yifrach is head of design and production specialization and instructor of the course: "Machining processes cutting".  Email: Yifrach@braude.ac.il
For more information, please contact Mr. Yitzchak Yifrach.

Objectives

  1. Training engineering students in the progressive machining process
  2. Establishing exclusiveness of the college in the subject of progressive machining process
  3. Fostering relevant research by academic staff
  4. Fostering cooperative students’ projects together with Iscar engineers , toward final projects 
  5. The lab supports teaching and research activities in machine design, machining processes and machine tools and other technical areas.
  6. A receipt of garnets in the academic exploratory part of the laboratory
  7. Providing services( commercial projects) to industries in the region


 
Machining Processes Laboratory

Policies: General, Safety

General
• No food or beverages are allowed in the laboratory area.
• Laboratory hours 8:00am-4:00pm.

Safety
• Most of the equipment in the lab is pre-configured in fixed stations. Under no circumstances you should try to move, troubleshoot, or open any equipment for any reason unless there is strong evidence that lack of your action may cause harm to a person or equipment.
• Eye protection is required for operation of all hand tools and powered, automated equipment, including CNC mills and lathe, and similar operations in the Lab.
• Long hair or loose clothing must be constrained to prevent getting caught in moving equipment.
• Watches, rings and other jewelry should be removed while operating all powered, automated equipment.
 Never attempt to operate any equipment without authorization and proper instruction. If you are uncertain about how a machine operates, ask the lab Coordinator for help.


 
Machining Processes Laboratory
Basic Machining Laboratory


The Basic Machining Laboratory consists of: manual lathe, vertical milling machine, drill press, grinding machine, and various cutting tools.

Mr. Hayyim salev is the Operator of conventional basic machines laboratory.
He manufactures partial machinery for lecturers that deal in research of different subjects in the mechanical engineering department.


Turning machine


Machining Processes Laboratory
Basic Machining Laboratory


Vertical milling machine


Drill press


 
Machining Processes Laboratory
Basic Machining Laboratory


Horizontal spindle surface grinder

 


Machining Processes Laboratory
Computer Numerical Control (CNC) Machining

 

Introduction
CNC Machining, or Computer Numerically Controlled Machining, is a fast, high-tech method of creating complex parts with very low tolerances in a short period of time.

General Information
The Computer Numerical Control, CNC, Machining process produces 3D objects by removing material. Automated milling machines are pre-programmed to cut away material according to a specific path.
Several cuts are usually necessary; first a rough cut using a large-radius bit (no tight inside corners) and then final cuts to exact dimensions. The processes of tool selection and changing, and cooling of the work piece are all automated and handled by the milling machine.
The advantages of using a CNC mill include
• Variety of materials
• Recyclables
• Capacity to produce high-quality metal molds
• Accuracy the CMM (Coordinate Measuring Machine) raises the accuracy of the tool movement (to within ± 0.01mm).

CNC mill uses G and M codes to describe the cutting and spinning motions of the tools as well as their speed.
• G codes specify motions while M codes specify machine commands.
• G code can be written by hand or generated by ProEngineer or Catia.


Machining Processes Laboratory
Computer Numerical Control (CNC) Machining


High precision CNC lathe turning
Takisawa TC-4 CNC 2 Axis Turning Center
 
Hitachi Seiki VA 65 CNC Vertical Machining Center 3 axis


Machining Processes Laboratory
Computer Numerical Control (CNC) Machining


The Computer Aided Design (CAD) covers theoretical and practical concepts including:
• Part modeling
• Assembly modeling
• Simulation model and FEM
To use the CNC Mill, a user must first create a Computer Aided Design (CAD) file using any of several CAD software packages available on campus. These include Catia, SolidWorks, and ProEngineer.

Example: Sketching Exercise
 
The geometric model that get accepted from the sketch with Catia software
 


 
Machining Processes Laboratory
Computer Numerical Control (CNC) Machining


After a model is created, tool selection and pathing must be programmed; the user decides where the cutting tool will go and when, and which tool will be mounted as it does so. This process can be programmed in Catia & ProEngineer here on campus or with other software packages. Having a part CNC milled at the CMU Mechanical Engineering machine shop is considerably simpler.

What materials can be used?
Materials that can be used include all of the following: Aluminum, Carbon Steel, Stainless Steel, Titanium, Magnesium, Brass, Copper, Special Alloys, Plastic, woods.

How much does it cost?
1. Cost depends on material, tolerance, and size.
2. Cost depends on the choice of material because certain stock materials are more expensive than others. Often higher grades of stock take more time to cut and are therefore more expensive. Harder materials cause more wear on the mill.
3. Cost depends on tolerance. Tolerances using a CNC milling machine can be as tight as 1 thousandth of an inch. Production tolerances are sometimes acceptable because human error and machine deviances are inevitable. The tighter the tolerances needed, the higher the cost.
4. Cost depends on size.
4.1.  Larger pieces lead to higher fixed cost (larger machine)
4.2.  Depending on complexity, parts take longer to machine and therefore cost more in terms of variable costs, including labor, excess material, and wear down.

 


Machining Processes Laboratory
Computer Numerical Control (CNC) Machining

 

What are some limitations?
CNC Milling is a very useful procedure. There are, however, a few limitations on what can be produced by the mill, and a few factors which must be considered to make an economical design.
1. The CNC mill uses rotary bits, so when milling inside corners a finite radius is unavoidable. Outside corners can be made quite sharp if necessary, but some inside corners can have as a minimum the radius of the cutting tool.
2. The workpiece must be solidly mounted to the milling table by a bracket piece, bolt holes, or a clamp. This should be taken into consideration when designing a part to be CNC milled. Of course the part can be mounted by a flange which is manually removed after machining.
3. Tool wear
3.1. Tool bits wear down and deteriorate with more use.
3.2.  Especially true if material being cut is as hard as the drill bit used (metal cutting metal)
4.  Machine code
4.1.  Must have NC file in the end to use the CNC milling machine.
4.2.  CAD must be exported to IGS format (ProE) or NC code must be written (can become very tedious) for the process to work.
5.  Size limitation 
5.1. The product being made must “fit” into the CNC machining station.


G and M Codes
G-Code serves for describing the tool path by means of coordinates, while M-codes are used for describing machine commands, such as tool types, speeds and starting the ending the program. Both are necessary to run the program.
 
Machining Processes Laboratory
Computer Numerical Control (CNC) Machining
Short introduction to G codes to know
G00  positioning (rapid traverse) G54  work coordinate system 1 select
G01  linear interpolation (feed)  G55  work coordinate system 2 select
G02  circular interpolation CW  G56  work coordinate system 3 select
G03  circular interpolation CCW G57  work coordinate system 4 select
G04  dwell G58  work coordinate system 5 select
G07   imaginary axis designation G59  work coordinate system 6 select
G09   exact stop check  G60  single direction positioning
G10   offset value setting G61  exact stop check mode
G17   XY plane selection G64  cutting mode
G18   ZX plane selection G65  custom macro simple call
G19  YZ plane selection G66  custom macro modal call
G20  input in inch G67  custom macro modal call cancel
G21  input in mm G68  coordinate system rotation ON
G22  stored stroke limit ON G69  coordinate system rotation OFF
G23  stored stroke limit OFF G73  peck drilling cycle
G27  reference point return check G74  counter tapping cycle
G28  return to reference point G76  fine boring
G29  return from reference point G80  canned cycle cancel
G30  return to 2nd, 3rd & 4th ref. point G81  drilling cycle, spot boring
G31  skip cutting G82  drilling cycle, counter boring
G33  thread cutting G83  peck drilling cycle
G40  cutter compensation cancel G84  tapping cycle
G41  cutter compensation left G85,G86   boring cycle
G42  cutter compensation right G87  back boring cycle
G43  tool length compensation + direction G88,G89  boring cycle
G44  tool length compensation - direction G90  absolute programming
G49  tool length compensation cancel G91  incremental programming
G45  tool offset increase G92  programming of absolute zero point
G46  tool offset decrease G94  per minute feed
G47  tool offset double increase G95  per revolution feed
G48  tool offset double decrease G96  constant surface speed control
G50  scaling OFF G97  constant surface speed control cancel
G51  scaling ON G98  return to initial point in canned cycle
G52  local coordinate system setting G99  return to R point in canned cycle
Machining Processes Laboratory

Computer Numerical Control (CNC) Machining


Short introduction to M codes to know
M00  program stop M21  tool magazine right
M01  optional stop M22  tool magazine left
M02  end of program (no rewind) M23  tool magazine up
M03  spindle CW M24  tool magazine down
M04  spindle CCW M25  tool clamp
M05  spindle stop M26  tool unclamp
M06  tool change M27  clutch neutral ON
M07  mist coolant ON M28  clutch neutral OFF
M08  flood coolant ON M30  end program (rewind stop)
M09  flood coolant OFF  M98  call sub-program
M19  spindle orientation ON M99  end sub-program


Machining Processes Laboratory
Computer Numerical Control (CNC) Machining

 

Example to the process of computerized production with Catia software

Example to part that required to manufacture
 

 

Stage of number 1- Building of suitable raw material to the problem

 

 

Machining Processes Laboratory
Computer Numerical Control (CNC) Machining


Stage of number 2 - Use the NC Catia software (CAM)

 

 

 


Machining Processes Laboratory
Computer Numerical Control (CNC) Machining

 

Stage of number 3 - preliminary definitions like:
1. Type of raw materials
2. System of axes
3. Type of machine & so on

 


Machining Processes Laboratory
Computer Numerical Control (CNC) Machining

 

Stage of number 4- Building the process production

4.1 - We start with choice a function from within menu

Examples of some optional functions

 


Machining Processes Laboratory
Computer Numerical Control (CNC) Machining

 

• After all the relevant definitions for all function, get accepted the full program
• You have to run a simulation to the testing of the results
 

 

The part that get accepted in the end of the simulation
 

 

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