SendCutSend Community College is our free, step-by-step video series designed to teach CAD and the fundamentals of designing parts for manufacturing. Whether you’re brand new to CAD or looking to build on your existing skills, the series covers everything from basic design principles to creating real, manufacturable parts.
Semester 1: CAD Fundamentals & Sheet Metal Design covered the essentials of CAD and designing for sheet metal manufacturing. Semester 2 is a free CNC machining course with 15 video lessons covering everything from milling fundamentals to programming and designing parts for production.
You’ll learn how CNC machines work, how parts are programmed and set up for production, and how design decisions affect machining time, cost, and quality. The goal is to help you understand not just how to design a part, but how that part actually gets made.
Below, you’ll find every Semester 2 lesson, along with a description and a link to watch. You can also access the full series for free at sendcutsend.com/education or on YouTube.
Chapter 1: Getting Started with CNC
Chapter One is about building a strong foundation in how CNC machining actually works, not just how to design parts in CAD. It walks you through the core ideas that connect your designs to real machines, from how CNC machines are built and move, to how they cut material and create features. The chapter breaks down the logic behind tooling, cutting behavior, workholding, and programming so you can understand what is physically happening during machining. By the end, you are not just designing parts, you understand how they are made and are prepared to create designs that are efficient, manufacturable, and reliable.
Chapter One Key Takeaways
- CNC machining is based on machine movement, tooling, and cutting logic, not just CAD geometry
- Understanding machine anatomy and axes helps you design parts that are actually reachable
- End mills and cutting tools define what shapes and features are possible
- Feeds, speeds, and cutting parameters directly impact cost, quality, and tool life
- Workholding and fixturing are critical for maintaining accuracy and preventing failure
- Toolpaths and cutting strategies control how material is removed and how parts are finished
- G code and coordinate systems are the language that connects your design to the machine
- Thinking like a machinist leads to better, more efficient, and more manufacturable designs
Lesson 1 Title: What is CNC Milling?
Welcome to Chapter One of CNC SendCutSend Education! In this first lesson, we’re laying the groundwork for CNC machining by getting familiar with the machine itself and the language machinists use every day.
We’ll walk through the anatomy of a CNC machine, breaking down key components like the spindle, collets, end mills, and the auto tool changer, and how they work together to remove material and create parts. From there, we’ll look at how parts are held using a vise and multi axis setups, and how probes help the machine understand tool position and part location in space. We’ll also cover the control panel, operator controls, and essential safety features that keep everything running smoothly.
What you’ll learn in this episode:
- The core components of a CNC machine and what they do
- How tools and material interact to remove material
- How parts are positioned using multi axis setups
- The role of probes in locating tools and parts
- Basic machine controls and key safety features
By the end of this lesson, you’ll have a strong understanding of the machine you’re designing for, setting you up for the next lesson where we explore how machine movement impacts your designs.
Lesson 2: How CNC Machines Cut and Impact Your Designs
In chapter 1 lesson 2, we build on machine anatomy by exploring how CNC machines move in space and how that directly impacts your designs.
We’ll break down the X, Y, and Z axes using the right hand rule, and show how the spindle and table interact to position the tool and material. From there, we’ll introduce three axis, four axis, and five axis machining, and how added rotation increases complexity while reducing setups and improving tolerances. Most importantly, we’ll explain the concept of the machine’s work envelope and why it defines the maximum size and reach of your part.
What you’ll learn in this episode:
- How CNC machines use X, Y, and Z axes to move in space
- The right hand rule and how machines interpret direction
- The difference between three, four, and five axis machining
- What the work envelope is and why it matters for your designs
- How machine limits affect part size and accessibility
By the end of this lesson, you’ll understand how machine movement and reach define what’s possible, helping you design parts that fit within real world manufacturing constraints.
Lesson 3: How to Design with End Mills in Mind
In chapter 1 lesson 3, we take a closer look at the tools doing the actual cutting: end mills, and how they directly influence your designs.
We’ll break down the different types of end mills, including flat, ball, and chamfer, and how their shapes determine the kinds of features you can create. From there, we’ll explore tool anatomy like flutes, cutting edges, and the difference between side cutting and plunging. We’ll also cover common tool materials like carbide and high speed steel, along with coatings that affect performance, heat, and durability.
What you’ll learn in this episode:
- The different types of end mills and what they’re used for
- How tool geometry affects part features and design limits
- The role of flutes, cutting edges, and cutting direction
- Differences between carbide and high speed steel tools
- How coatings impact performance and material compatibility
By the end of this lesson, you’ll understand how end mills shape what’s possible in CNC machining, helping you design parts that align with real cutting tools and processes.
Lesson 4: How to Design Using CNC Feeds and Speeds
In chapter 1 lesson 4, we break down feeds and speeds and how they directly impact both your design and the cost of your parts.
We’ll introduce key concepts like RPM, inches per minute, chip load, and surface feet per minute, and explain how they all work together when an end mill interacts with material. From there, we’ll walk through how to calculate feed rate, what happens when you push things too fast or too slow, and how these decisions affect tool life, surface finish, and machining time.
What you’ll learn in this episode:
- What RPM, feed rate, chip load, and surface speed mean
- How these values work together during cutting
- How to calculate feed rate and understand machining time
- The risks of running too fast or too slow
- How feeds and speeds impact cost, quality, and tool life
By the end of this lesson, you’ll understand how cutting parameters influence performance and cost, helping you design parts that are efficient to machine and optimized for real world production.
Lesson 5: How to Design Parts for CNC Workholding
In chapter 1 lesson 5, we get into workholding and fixturing, and how they play a critical role in whether your parts succeed or fail.
We’ll explore how parts are secured inside a CNC machine using vises, soft jaws, and fixtures, and why stability is essential for maintaining tolerance, preventing chatter, and avoiding tool breakage. From there, we’ll break down different types of vises, how multi axis setups affect fixturing, and what happens when you need to machine every side of a part. We’ll also cover design considerations like no cut zones, part orientation, and how fixturing decisions can impact cost.
What you’ll learn in this episode:
- Why secure workholding is critical for part quality and accuracy
- Common fixturing methods including vises, soft jaws, and fixtures
- How part movement affects tolerance, finish, and tool life
- Key design considerations for clamping and accessibility
- How fixturing choices impact cost and production efficiency
By the end of this lesson, you’ll understand how parts are held during machining and how to design with fixturing in mind to ensure stable, accurate, and cost effective results.
Lesson 6: How to Design Parts That Machine Faster and Cleaner
In chapter 1 lesson 6, we break down the fundamentals of CNC toolpaths and how cutting strategies impact both the finish and cost of your parts.
We’ll cover the difference between roughing and finishing passes, how and why stock is left behind, and how multiple tools are used to balance speed and precision. From there, we’ll explore key concepts like radial and axial stock, tool deflection, and how tool size affects internal features. We’ll also introduce climb cutting versus conventional cutting and how cutting direction influences surface finish and machining efficiency.
What you’ll learn in this episode:
- The difference between roughing and finishing passes
- Why stock is left behind and how it improves results
- How tool size affects detail and internal radii
- The impact of tool deflection on accuracy and finish
- The difference between climb cutting and conventional cutting
- How cutting strategies influence cost, quality, and efficiency
By the end of this lesson, you’ll understand how toolpath strategies shape the final part, helping you design parts that machine efficiently while achieving the desired finish and precision.
Lesson 7: How to Design Parts Using Adaptive and Pocket Toolpaths
In chapter 1 lesson 7, we continue building on toolpath strategies by exploring how tool engagement and cutting patterns impact performance, finish, and cost.
We’ll break down the concept of tool engagement and why balancing it is key to avoiding tool breakage while maximizing efficiency. From there, we’ll compare two common roughing strategies, adaptive clearing and pocket clearing, and show how each affects cutting forces, tool life, and machining stability. We’ll also introduce step down and step over, and how adjusting these values changes cutting aggressiveness, surface finish, and machining time.
What you’ll learn in this episode:
- What tool engagement is and why it matters
- The difference between adaptive clearing and pocket clearing
- How cutting strategy affects tool stress and efficiency
- What step down and step over mean in CNC machining
- How to balance speed, finish, and tool life
By the end of this lesson, you’ll understand how cutting engagement and strategy influence machining performance, helping you design parts that are both efficient to produce and optimized for quality.
Lesson 8: How to Design Parts for CNC Contouring and Drilling
In chapter 1 lesson 8, we wrap up our toolpath concepts by exploring how tools enter material and how final operations like contouring and drilling are programmed.
We’ll break down contour toolpaths and how they follow part profiles to achieve accurate final dimensions and clean finishes. From there, we’ll cover drilling operations, including different strategies for chip evacuation like pecking and full retract cycles. We’ll also explore multiple entry methods for end mills, such as helical entry, ramping, plunging, and pre-drilled entry points, and how each impacts tool life, stability, and cut quality.
What you’ll learn in this episode:
- How contouring is used to finish part profiles
- The basics of drilling operations and hole creation
- Different drilling cycles and chip removal strategies
- How end mills enter material using various entry methods
- How entry strategy impacts tool life, finish, and efficiency
By the end of this lesson, you’ll understand how tools safely and efficiently enter and finish cuts, helping you design parts that are easier to machine and produce more reliable results.
Lesson 9: How to Understand CNC Machine Coordinates and G-Code
In chapter 1 lesson 9, we introduce G-code and how CNC machines understand and execute your designs.
We’ll break down how machines track position using machine home and work coordinate systems, and how offsets allow you to define where your part exists in space. From there, we’ll walk through the basics of G-code, including common commands for movement, spindle control, feed rates, and tool changes. You’ll also see how these commands come together to control every step of the machining process.
What you’ll learn in this episode:
- The difference between machine home and work coordinate systems
- How work offsets define part position in the machine
- What G-code is and how it controls CNC machines
- Common commands for movement, spindle speed, and tool changes
- How CNC programs are structured and executed
By the end of this lesson, you’ll understand the language behind CNC machining, helping you connect your designs to how machines actually interpret and produce them.
Chapter 2: Designing for CNC Machining
Chapter Two is about applying CNC concepts to real world parts and learning how designs turn into finished components. It walks you through the full process of taking a CAD model into CAM, setting up material, planning machining operations, and programming toolpaths. The chapter teaches you how setups, machine capabilities, and programming decisions impact cost, accuracy, and efficiency. By the end, you are not just understanding CNC concepts, you are applying them to real parts and thinking like both a designer and a programmer.
Chapter Two Key Takeaways
- Real world CNC parts require both design and programming thinking
- Setup and material selection are critical to successful machining
- Fewer setups lead to better accuracy, lower cost, and faster production
- Three axis and five axis strategies change how parts are made
- Programming requires planning toolpaths, tools, and order of operations
- Simulation helps catch issues before parts are cut
- Small design changes can significantly reduce machining time and cost
- Understanding the full workflow leads to better, more manufacturable designs
Lesson 1: How to Design a GoPro Mount for CNC Machining
In chapter 2 lesson 1, we start applying what we learned in chapter 1 by designing a real world CNC part: a GoPro mount.
We walk through the purpose behind the design and how specific features are intentionally chosen to demonstrate key machining concepts throughout the chapter. From mounting tabs and hole placement to radii and part geometry, every element is designed to highlight how design decisions impact manufacturability, cost, and performance.
What you’ll learn in this episode:
- How to approach designing a real world CNC part with SendCutSend
- How part features relate to machining processes
- Why certain design choices affect cost and efficiency
- How to create a foundational part for continued learning
- How prior CAD and CNC knowledge come together in practice
By the end of this lesson, you’ll have a complete part design that will be used throughout the chapter, giving you a hands-on way to understand and apply CNC programming concepts moving forward.
Lesson 2: How to Create a CNC Setup in CAM
In chapter 2 lesson 2, we walk through the first step of CNC programming: creating a setup and preparing your part for machining.
We’ll cover how to choose the right raw material size, how parts are positioned within a billet, and why proper spacing is critical for machining all surfaces. From there, we’ll step through setting up your part in CAM, including defining orientation, selecting a work coordinate system, and creating your stock. You’ll also learn how setup decisions impact machining strategy, material usage, and overall part quality.
What you’ll learn in this episode:
- How to select the right billet size for your part
- How to position your part within raw material
- How to create a setup in CAM software
- How to define orientation and work coordinate systems
- How setup choices affect machining and material efficiency
By the end of this lesson, you’ll understand how to properly prepare a part for CNC machining, setting the foundation for accurate programming and successful part production.
Lesson 3: How to Design for 3 Axis vs 5 Axis CNC Machining
In chapter 2 lesson 3, we compare three axis and five axis setups and how they impact part quality, efficiency, and cost.
We’ll explore how multiple setups on a three axis machine can introduce error through repositioning, while five axis machining allows you to complete more features in a single setup. From there, we’ll walk through how part orientation and work coordinate systems change between setups, and why maintaining consistent references is critical for accuracy. You’ll also see how these differences show up in CAM and how they affect programming and real world results.
What you’ll learn in this episode:
- The difference between three axis and five axis setups
- How multiple setups introduce error and tolerance stack up
- Why fewer setups improve accuracy and consistency
- How to manage part orientation and coordinate systems
- How machine choice impacts cost, speed, and quality
By the end of this lesson, you’ll understand how setup strategy affects your final part, helping you design parts that minimize error, reduce setups, and improve overall machining efficiency.
Lesson 4: How to Program a Part in CAM: 3 Axis Workflow
In chapter 2 lesson 4, we step into the role of a CNC programmer and walk through what it takes to machine our class project on a three axis mill.
We’ll go through the full programming workflow, including planning the order of operations, selecting tools, and creating multiple setups to access different features of the part. From drilling and tapping to roughing, finishing, and part flipping, you’ll see how material is removed step by step and how each decision impacts the final result. We’ll also use simulation to catch issues like collisions and better understand how the machine executes the program.
What you’ll learn in this episode:
- How CNC programmers plan the order of operations
- How multiple setups are used on a three axis machine
- How different toolpaths are used to remove material
- How simulation helps identify issues before machining
- How programming decisions affect cost, time, and part quality
By the end of this lesson, you’ll understand the full machining process from a programmer’s perspective, helping you design parts that are easier to machine and more efficient to produce.
Lesson 5: How to Reduce CNC Part Cost Through Design
In chapter 2 lesson 5, we refine our class project by making small design changes that have a big impact on manufacturability and cost.
We’ll revisit the original GoPro mount design and remove select features to simplify the machining process while maintaining functionality. From eliminating unnecessary radii to removing a tapped hole and extra tabs, you’ll see how reducing tool changes, setups, and machining time leads to a more efficient part. We’ll also compare the updated toolpaths to show exactly how these changes streamline production.
What you’ll learn in this episode:
- How small design changes impact machining time and cost
- How reducing tool changes improves efficiency
- When to simplify features without losing functionality
- How design decisions affect CNC programming complexity
- How to optimize parts for faster and more cost effective production
By the end of this lesson, you’ll understand how to refine your designs for manufacturability, helping you create parts that are easier to machine and more affordable to produce.
Lesson 6: Go Pro Mount Livestream
In the final lesson of Semester 2, we bring everything together in a live stream as we cut our semester project in real time.
Watch as the GoPro mount goes from raw material to a finished part, following the exact setups, toolpaths, and strategies covered throughout the course. You’ll see how the machine executes the program, how material is removed step by step, and what the final results look like in practice.
What’s Next?
We’re continuing to grow our education series and community college lessons. Head to the SendCutSend Education hub and follow along on YouTube.
