manufacturing and desighn of cnc milling machine

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MGMs COLLEGE OF ENGINEERING AND TECHNOLOGY,KAMOTHE

A Seminar On

DESIGN & FABRICATION OF CNC MILLING MACHINE

Group members :

Mr. Dinesh V. Awari Mr. Manoj S. Bhamare Mr. Akshay S.GhanwatMr. Ketan M. Jadhav

Guided By:- Prof. Jagdish M. Chahande

CNC MILLING MACHINE

IntroductionOur CNC Machine is a personal version of a CNC machine. It is controlled by your computer and is designed for the hobbyist to create objects within a relatively compact space and at modest expense. With the help of CNC technology, machine tools today are not limited to human capabilities and are able to make ultra-precision products down to nano scales in a much faster manner. The traditional design philosophy of machine tools is multifunctionality and highest precision possible.

Literature ReviewSr. No.Name Of Research PaperAuthorYearThesis1. Semiautomatic Drilling Machine ControllerProf. R. N. Panchal, Prof. J.R. Panchal2016Trying to propose low cost design usingwhich similar functionality as that of CNC can be achieved.

2.Design of low Cost CNC Drilling MachineGautam Jodh , Piyush Sirsat.2014Machine isdesigned with a view to keep the cost of the machine at minimum.

3.Development of a Prototype CNC Machine Vatsal Suthar, Dhaval Patel2015Brings CNC technology to a size and price that will fit in our home or office 4.Prototype CNC Machine DesignRogrio D. S. Souza2012Development of a machine which allows futureresearches on the process performance, on educational purposes, the demonstration of the parts involved on the CNC machine.

5.Effect Of Machining Parameters On Surface Quality After Face Milling Of MDF Abdullah Stc 2011Focused on machining parameters which are related the surface roughness of the pocket milled MDF routed by a CNC machine 6.Design And Implementation Of 3-axis Linear InterpolationController In FPGA For Cnc Machines And RoboticsDr. Usha S. Mehta2014The simulation results of the linear motion in 3D spaceverify the effectiveness of the implemented algorithm.

7.An Investigation Effect of Machining Parameters on CNC Mr.Dhruv H. Patel, Prof. V. N. Patni 2014Study on CNC, influence of various machining parameters like, tool speed (rpm ), tool feed (mm/min), and depth of cut (mm) 8.Construction And Evaluation Of Low-cost Table CNCMilling MachineIvo Pahole, Luka Rataj, Mirko Fick2013In the continuation the tests and checking of static rigidity,positioning accuracy and repeatability are discussed

Problem DefinitionYet most mills are costly and difficult to use, keeping them out of reach for individuals and small businesses. High initial cost and requirement of skilled labour for operating the CNC machine not suitable for use in small or medium scale industries. In many Indian engineering educational institutions the CAD/CAM and Manufacturing Technology Laboratories are equipped mainly with large commercial CNC machines which are prohibitively expensive and moreover are overdesigned considering the pedagogical needs of undergraduate students. They come with costly annual maintenance contracts and are time-consuming and expensive to repair in the case of breakdowns.

ObjectiveTo full fill the demand of CNC machine from small scale to large scale industries with optimized low cost.Using Arduino-based control system is a major new development in computer technology is the availability of low-cost open source hardware. Clear, easy to follow design Comprehensive construction and operation manual .For the development of low-cost educational models of CNC machines, such tools may be quite adequate from the viewpoint of machine control.

Methodology

Basic CNC Equipments

Main SystemsThis system can be divided in to three modules :-Mechanical systemElectrical systemSoftware system

Working

PC RUNNING MACH 3

Parallel port or USB

Breakout bordPower supply Stepper driveStepper driveStepper driveM1M2M3

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Components

MECHANICAL COMPONENT :BALL/ LEAD SCREWS BALL BEARINGS LINEAR RODS LINEAR BALL BEARINGS SHAFT END SUPPORTSELECTRICAL COMPONENT :MICROCONTROLLER BOARD STEPPER MOTOR STEPPER MOTOR DRIVER BOARDLIMIT SWITCHES Computer software

Ball / Lead Screws A ball screw is a mechanical linear actuator that translates rotational motion to linear motion with little friction. A threaded shaft provides a helical raceway for ball bearings which act as a precision screw. As well as being able to apply or withstand high thrust loads, they can do so with minimum internal friction.

Ball Bearings

A ball bearing is a type of rolling-element bearing that uses balls to maintain the separation between the bearing races.The purpose of a ball bearing is to reduce rotational friction and support radial and axial loads.

Linear RodsLinear rods are rigid strong Mild Steel shafts which are used to carry the load with out affecting the motion and supports linear movement.Linear rods with linear bearing assembly are used to carry the loads and supports the structures in linear motions the total load of the structure is taken away by the linear rod bearing assembly and therefore the load on ball screw is reduced and causes precise smooth linear motion.

Linear Bearings A linear bearing is to provide free motion in linear direction. The load is carried away by the linear bearing and reduces friction slides over linear rods. A linear-motion bearing or linear slide is a bearing designed to provide free motion in one direction. It features smooth motion, low friction, high rigidity and long life. They are economical, and easy to maintain and replace.

Shaft End Support Shaft supports are used to support linear rods /shafts rigidly without slip.Shaft support blocks are used for end or intermittent support where loads are light and slight shaft deflection is not a concern.

Stepper Motor A stepper motor is a brushless, synchronous electric motor that converts digital pulses into mechanical shaft rotation in a number of equal steps.The motor's position can then be commanded to move and hold at one of these steps without any feedback sensor (an open-loop controller).A NEMA 23 stepper motor is a stepper motor with a 2.3 x 2.3 inch size is chosen to drive the motion of the axes.NEMA 23 stepper motors are high torque about 19KG-Cm holding torque .NEMA 23 stepper motors have 1.8 degree step angle with 2.5A rated current.

Stepper Motor Driver Board Driving a stepper motor is a bit more complicated than driving a regular brushed DC motor. Stepper motors require a stepper controller to energize the phases in a timely sequence to make the motor turn.RMCS-1102 is micro-stepping drive designed for smooth and quiet operation is chosen to drive the NEMA 23 stepper motorRMCS-1102 achieves micro-stepping using a synchronous PWM output drive. Mismatched motors and drivers can result in disappointing performance. Or worse: damage to the motor and/or controller.

Microcontroller Board Atmega 328 p Arduino Development board is used as the motion control board. Atmega 328 p is a 16 bit 24 pin ARM Architecture microcontroller. The microcontroller is flashed with the GCODE interpreter firmware written in optimized C language .Motion control is carried away through output pins connected to the stepper motor drives according to the firmware code in microcontroller. Inputs like RESET, FEED HOLD, CYCLE START/RESUME and axis Limits are given to the Inputs of microcontroller

Limit Switches A Limit Switch is the simplest type of end stop a simple mechanical switch positioned to trigger when a axis reaches the end of its motion.Limit switches are used to protect the stepper motor and circuit by shutting the motors by triggering the switch when the axis reaches its end . The signal pin from limit switches are connected to the microcontroller board to sense the axes ends.

Design This CNC machine creates objects from wood. CNC stands for computer numerical control. The CNC works on the Cartesian coordinate system (X, Y, Z) for 3D motion control. Parts of a project can be designed in the computer with a CAD/CAM program, and then cut automatically using cutters to produce a finished part. This CNC machine is ideal for hobbies, engineering prototyping, product development, art, and production work.

Rough Sketches

Z axis assembly and stepper motor connection

Auto Cad Design

Isometric view

Auto Cad Design

Isometric View

Top ViewFront ViewRHS View

DiamensionsBase = 3 x 2.5Column=1-8 x 1-5Workpice table=1-3 x 3 Z-axis assembly=1-1 x 9

Mach 3 SoftwareMach3 turns a typical computer into a CNC machine controller. It is very rich in features, works on most Windows PC's, and is customizable for many applications. Mach3 is the most intuitive CNC control software available.Main features include: Allows direct import of DXF, BMP, JPG, and HPGL files through Lazy-CamVisual G-code displayGenerates G-code via Lazy-Cam or WizardsFully customizable interfaceCustomizable M-Codes

Mach 3 Software

Application This CNC machine can be used in the production of many different items, such as door carvings, interior and exterior decorations, wood panels, sign boards, wooden frames,moldings , musical instruments, furniture, and so on.It is perfect way to create prototypes using aluminum, foam, wood and plastics. Using the right software and efficiently create prototypes and reproduction parts.There are one of the most versatile tools for any woodworking operation. Cut to size, rout, chamfer, rabbet, v-groove, dado, pocket, carve and more.With the development of powerful, easy-to-use software and a CNC machine, just about anyone can carve beautiful parts, even if he is not a world-class hand carver

Market Survey of some partsPartsPriceMicrocontroller (UNO)500-1000/-Stepper Motor1000-2000/-Drive Board(ULN 2003 Board)400-500/-Flexible connector300-500/-

Future WorkIt is planned to scale up the CNC machine in terms of size, use more powerful motors, strengthen the frame and worktable with materials like aluminum or cast iron, and augment the CNC control software with software for simulation ahead of actual runTime requirementFabrication of parts AssemblyPerformance testing

ConclusionWith the increasing demand for small scale high precision parts in various industries, the market for small scale machine tools has grown substantially. Using small machine tools to fabricate small scale parts can provide both flexibility and efficiency in manufacturing approaches and reduce capital cost, which is beneficial for small business owners. In this thesis, a small scale three axis CNC milling machine is designed and analyzed under very limited budget.

Reference www.nplindia.orgwww.wikipedia.org Yung C. Shin, Henry Chin, Michael J. Brink, Characterization of CNC machining centers, Journal ofManufacturing Systems,1991 Heisel, M Gringel, Machine Tool Design Requirements for High Speed Machining,1999 M Kumar, V Puttige, low cost automation for CNC machining center, IJMET, Vol. 3. I. Pahole, L. Rataj, M. Ficko, S. Klancnik, S.Brezovnik, M. Brezocnik, and J. Balic,"Construction and evaluation of low-cost tableCNC milling machine",2009 V.K. Pabolu and K.N.H. Srinivas, "Design and implementation of a three dimensional CNC machine",2010. T. Andrei and I. Nae, "Practical applications performed by a stepper motor CNC router",2010 P.A. Sherring da Rocha Jr., R.D.S. Souza, and M.Emilia de Lima Tostes, "Prototype CNC machinedesign",2012 Xu, Y. Li, J. Sun, and S. Wang, "Research and development of open CNC system based on PC and motion controller",2012. www.fortune.orgwww.headland.comwww.machinetoolhelp.comwww.cncezpro.com