CNC tutorial | Lesson 1: Introduction & CNC Process Overview

1.1  Course Description

The goal of this course is to teach persons with a technical background how to program and operate Computer Numerical Control (CNC) mills and lathes.

This course bridges the gap between what persons with a technical education know and what they must learn to begin using CNC machine tools. The types of parts, materials and machining operations that engineers, innovators, and niche manufacturers often use are featured. Work holding techniques well suited to prototype and short−run production are detailed and used as examples.

Prerequisites

The learner is expected to have the following:

• Engineering or other technical degree or equivalent
• Knowledge of the proper use of basic hand tools and precision measuring instruments, including calipers and
• Some manual machining experience is helpful but not
• Knowledge of Solidworks is a pre−requisite or co−requisite for this course.

Audience

This course is designed for the following audiences:

• Working engineers and designer.
• Engineering undergraduates or graduate students.
• Manufacturing and design students.
• Scientists.
• Innovators.
• Niche Manufacturers.

Course Design

CNC Machining is a very broad subject and there are many ways to do most things. Covering all options would fill volumes and is beyond the scope of any one book or course. The goal of this course is not to turn and engineer into a journeyman machinist. Rather, it is to show how to use CNC to make common types of parts, teach DFM principles, and help engineers become better designers and managers.

This curriculum was created using an Instruction Design process. Engineering educators and students from leading Universities, as well as practicing engineers in a variety of industries, were surveyed. This process determined the types of parts and materials covered in this course. Parts that are easier made using Additive Rapid Prototyping (RP) technologies were excluded.

جهت خرید قطعات سی ان سی و اطلاع از قیمت های لوازم cnc اینجا کلیک کنید.

By leveraging what anyone with a technical education knows, by focusing on the most common types of parts and materials, and by presenting best practices for prototype machining, learning objectives are narrowed considerably. Thus a remarkable amount can be achieved in a short time. For example, working engineers using this course have been taught to set up, program, and operate a CNC mill in less than 24 hours of combined classroomƒlab time; including instruction in HSMWorks.

This economy of instruction makes CNC accessible to almost anyone: from working engineers to students involved in designƒbuild competitions, to undergraduate engineering students as part of a Design for Manufacturing (DFM) course or hand−on lab.

SRP vs. RP

This course emphasizes an approach to CNC machining referred to as Subtractive Rapid Prototyping (SRP). SRP deals with small quantities of functional prototypes. Functional prototypes are made from materials like aluminum, steel and polycarbonate that cannot be produced with widely available additive Rapid Prototyping (RP) processes such as SLA (Stereolithography) or FDM (Fused Deposition Modeling).

SPR is not as simple to learn and use as RP. It takes more skill and often more time to apply. The main advantage of SRP is in materials. Almost anything can be machined. SRP parts are not just visual aids, they are structural components that can be tested and assembled as part of working machines.

Another advantage of SRP is that it teaches real manufacturing constraints typical of the aerospace, biomedical, consumer goods, and electronics industries −all which use CNC for mass production, molds and other tooling. RP does not reflect these constraints. A part that is easy to rapid prototype may be extremely difficult, expensive, or even impossible to manufacture. SPR provides the designer with feedback about the manufacturability of design that can save considerable time and money as a part moves from concept to product.

Prototype vs. Production Machining

One of the biggest differences between making a few or many parts is in the design of work−holding fixtures. Prototype machining emphasizes quick, simple and cheap work holding solutions such as vises, clamps, screws or even glue or double−sided tape. High production parts allow the cost of fixtures to be amortized over larger quantities to justify the cost of more elaborate and efficient fixtures. This course emphasized prototype fixturing.

1.2 Required Tools and Equipment

CNC Machine

To maximize learning, this course focuses on CNC machines made by Haas Automation, Inc. of Oxnard, CA. Chapters 5 (CNC Programming Language) and 6 (CNC Operation) are written specifically for the Haas control. Haas machines are highlighted for the following reasons:

• Haas Automation is the largest machine tool builder in the western
• Haas has donated or endowed many machines to colleges, universities, and technical schools, so they are likely to be found in educational
• All Haas machines use the same control, work similarly, and use industry standard What is learned is easily transferred to other make or model machines.
• Haas makes several small footprint CNC machines designed specifically for engineering, prototyping, medical, jewelry, and niche manufacturing

SolidWorks + HSMWorks

This    course    uses    SolidWorks®    CAD    software    and    SolidWorks−Integrated    CAM    (Computer−Aided Manufacturing) software by Autodesk, Inc. for CNC programming. SolidWorks is widely used by both industry and education for mechanical design. HSMWorks is completely and seamlessly integrated into SolidWorks, is very easy to learn and use and is particularly well−suited to persons who know SolidWorks and

are new to CNC programming. HSMWorks also stores all data in the SolidWorks Part or Assembly file which makes file management simpler. If the learner already knows how to use SolidWorks they already know most of what they need to use HSMWorks.

جهت خرید قطعات سی ان سی و اطلاع از قیمت های لوازم cnc اینجا کلیک کنید.

All of these attributes are essential for a streamlined course in CNC machining possible. They save the substantial time takes to learn the completely separate interface and way of working required to use older technology “stand−alone” CADƒCAM software.  Our experience has shown the distraction and time needed to learn stand−alone CAM is a major obstacle to learning CNC and adds no value to the learning experience. In short, stand−alone CAM in this setting is all pain and no gain.

HSMWorks cuts CAM learning time easily by 75% or more. This frees class time, reduces learner frustration and focuses attention where it belongs: on how to set up, program and run CNC machine tools −rather than how to learn a completely separate (and often quirky) stand−alone CADƒCAM software application.

1.3 Lessons & Appendices

Lessons

• Overview/Resources
• Shop Safety
• Coordinate Systems
• CNC Programming Language
• CNC Tools
• CNC Operation
• 2D Milling Toolpaths
• CNC Turning

Appendices

• CNC Milling Work−Holding Examples
• Alternate Tool Setting Methods
• CNC Process Planning Forms
• G/M Code Reference
• Glossary
• Drill Chart

1.4 Instructional Resources

Instructor Resources

• PowerPoint presentations for each lesson.
• Lesson guides.
• Exercises: SolidWorks files with HSMWorks toolpaths completed.
• Videos with step−by−step instructions how to complete each exercise.
• Assessment with solution for each lesson.

Student Resources

• Reading assignments for each lesson.
• Videos (SWF) for each lecture (PowerPoint).
• Videos with step−by−step instructions how to complete each exercise.
• Exercises: SolidWorks files.

1.5 Recommended Use

To get the most from this course, proceed as follows:

• Read the Reading Assignment for each lesson (PDF).
• Watch the video of each lecture, or attend a live lecture conducted by the instructor.
• Watch the video for the practical assignment.
• Complete the assignment using Work through the assignment more than once if possible. Make sure you understand each step and why you are doing what the assignment requires.
• Make the project parts on the CNC machine.
• Take the assessment for the lesson.

1.6 Overview of CAD/CAM Process

The general workflow to go from CAD model to machined CNC part is:

1. Begin with CAD model.
2. Establish Job parameters including CNC coordinate system and stock shape/size.
3. Select CNC process.
4. Select cutting tool and machining parameters.
5. Select driving CAD
6. Verify toolpath.
7. Post Process.
8. Transfer G−code program to CNC machine.
9. Set up and operate CNC machine to make part.