INTRODUCTION TO CNC MILL PROGRAMMING

Summary

This instructional video script introduces the basics of CNC programming for a CNC mill, focusing on the Cartesian coordinate system's relevance to CNC. It explains the concept of positive and negative values in the X and Y axes, the significance of the origin, and how these values change with different quadrants. The script also touches on the Z-axis, crucial for depth in milling operations. It aims to demystify CNC programming by illustrating how machines understand coordinates to perform tasks like drilling holes in a block, emphasizing the importance of establishing the origin for accurate machining.

Takeaways

• 📚 The video script is an educational resource on basic CNC programming for CNC mills.
• 📐 It introduces the Cartesian coordinate system as it relates to CNC programming, focusing on the X and Y axes.
• 📍 The origin is defined as the intersection of the X and Y axes, where both have a value of zero.
• ➕ Understanding the positive (+) and negative (-) values of coordinates is crucial for CNC programming.
• 🔄 The script explains how moving in different directions from the origin results in different X and Y values.
• 🔺 Points in different quadrants have specific combinations of positive and negative X and Y values.
• 📈 The script uses an 8x8 square grid to illustrate how the position of the origin affects the coordinates of points.
• 🔄 It also demonstrates how shifting the grid to a different quadrant changes the X and Y values of the points.
• 🔱 The Z-axis is introduced as the third plane, adding depth to the two-dimensional X and Y plane.
• 🔩 The importance of determining the origin's location when setting up a part in the machine is emphasized.
• 🛠 The script concludes by setting the stage for the next video, which will discuss selecting coordinates for tool paths in milling.

Q & A

What is the purpose of the video series on CNC programming for the CNC mill?

The purpose of the video series is to explain the basics of CNC programming, including the meaning of the coordinates (X, Y, Z), the G and M codes, and how to understand and create CNC programs.

What is the Cartesian coordinate system and how does it relate to CNC programming?

The Cartesian coordinate system is a mathematical model used to define positions on a plane or in three-dimensional space. In CNC programming, it is used to determine the position of the tool relative to the part being machined, using X, Y, and Z axes.

What is the significance of positive and negative values in the Cartesian coordinate system as it pertains to CNC programming?

Positive and negative values in the Cartesian coordinate system are crucial in CNC programming as they indicate the direction of movement along the X, Y, and Z axes. They help the CNC machine to know whether to move in a positive (right, up, or away from the origin) or negative (left, down, or towards the origin) direction.

How is the origin defined in the context of the video script?

In the context of the video script, the origin is defined as the point where the X and Y axes intersect, with both X and Y values being zero. The origin serves as the reference point for all other coordinates in the CNC program.

What are the four quadrants of the Cartesian coordinate system and how do they affect the sign of the coordinates?

The four quadrants of the Cartesian coordinate system are numbered I to IV. In quadrant I, both X and Y have positive values. In quadrant II, X is negative, and Y is positive. In quadrant III, both X and Y are negative. In quadrant IV, X is positive, and Y is negative. The quadrant in which a point lies determines the sign of its coordinates.

Why is it important to understand the placement of the origin in a CNC program?

Understanding the placement of the origin is important because it determines the X and Y values and their signs. The origin's position affects how the CNC machine interprets the coordinates for tool movement, which in turn affects the machining process.

What is the Z axis in the context of a three-axis CNC mill, and how does it differ from the X and Y axes?

The Z axis represents the height or depth in a three-axis CNC mill. It differs from the X and Y axes, which represent the horizontal and vertical positions on a plane, respectively. The Z axis allows the CNC machine to move the tool up and down, adding depth to the machining process.

How does the CNC machine interpret the movement of the tool in the Z axis?

The CNC machine interprets movement in the Z axis as the tool moving towards or away from the workpiece. A positive Z value indicates the tool moving away from the workpiece, while a negative Z value indicates the tool moving towards the workpiece.

What is the significance of the Z axis in relation to the machining process?

The Z axis is significant in the machining process as it allows for the creation of three-dimensional shapes. It controls the depth of cuts, the height of the workpiece, and the movement of the tool in the vertical direction.

How does the video script illustrate the importance of understanding the Cartesian coordinate system for CNC programming?

The video script illustrates this by showing how the placement of the origin and the understanding of the quadrants affect the coordinates used in a CNC program. It uses an example of drilling holes in a block, demonstrating how the coordinates change based on the origin's location and the direction of the tool movement.

Outlines

00:00

📐 Introduction to CNC Programming and Cartesian Coordinates

This paragraph introduces the viewer to the basics of CNC programming, specifically focusing on understanding the Cartesian coordinate system as it relates to CNC milling. The speaker explains the concept of the X and Y axes, the origin point where both axes intersect, and how movement in different directions results in positive or negative values for each axis. The explanation includes the division of the coordinate plane into four quadrants, each with distinct rules for determining the sign of the coordinates based on their location. The importance of understanding these concepts is emphasized for interpreting CNC programs, which use these values to control machine movement.

05:02

🔍 Applying Cartesian Coordinates to CNC Milling Operations

In this paragraph, the application of the Cartesian coordinate system to a practical CNC milling scenario is discussed. The speaker uses an 8x8 square grid to represent a block with holes that need to be drilled, illustrating how the machine is instructed to locate these points in relation to the origin. The concept of shifting the origin to different quadrants and how it affects the X and Y values of the points is explained. Additionally, the introduction of the Z-axis is introduced to account for the depth or thickness of the material being machined, showing how the machine moves in positive and negative Z directions during the drilling process. The importance of correctly setting the origin and understanding the resulting coordinate values is highlighted for successful CNC operation.

Keywords

💡CNC programming

CNC programming refers to the process of creating instructions for a computer numerical control (CNC) machine to execute tasks such as cutting, shaping, or drilling materials. In the video, CNC programming is the central theme, with the focus on understanding the language and commands that control the movement of a CNC mill.

💡Cartesian coordinate system

The Cartesian coordinate system is a mathematical model used to define positions on a two-dimensional plane using ordered pairs of numbers, typically represented as (x, y). In the context of the video, it is fundamental to CNC programming as it helps to understand how positions are determined on the machine's workspace.

💡Origin

The origin in the Cartesian coordinate system is the point where the x and y axes intersect, represented as (0, 0). In the video, the origin is used as a reference point to determine the coordinates of the points in the CNC program, which is crucial for accurate machining.

💡Quadrants

Quadrants are the four equal areas formed by the intersection of the x and y axes in the Cartesian coordinate system. The video explains how the position of a point in different quadrants affects the sign of its coordinates, which is essential for CNC programming to determine movement direction.

💡Plus and minus values

In the context of the video, plus and minus values refer to the direction of movement along the x and y axes in the CNC machine. Positive values indicate movement in the positive direction of an axis, while negative values indicate movement in the opposite direction, which is critical for precise control of the machine.

💡X-axis and Y-axis

The x-axis and y-axis are the two perpendicular axes in the Cartesian coordinate system that define horizontal and vertical positions, respectively. In the video, understanding the x and y axes is essential for determining the coordinates for CNC milling operations.

💡Z-axis

The Z-axis is the vertical axis perpendicular to the X and Y planes, used to represent depth or height in three-dimensional space. In the video, the Z-axis is introduced to explain how the CNC machine can move in and out of the material being machined, adding a third dimension to the machining process.

💡G-codes and M-codes

G-codes and M-codes are part of the CNC programming language, where G-codes control the movement and positioning of the machine, and M-codes are used for miscellaneous functions. Although not explicitly mentioned in the transcript, understanding these codes is crucial for writing CNC programs, as they are the commands that the machine follows.

💡Milling

Milling is a machining process that uses a rotating cutting tool to remove material from a workpiece. In the video, the concept of milling is related to the CNC programming of the machine to move the cutting tool along specific paths to shape the material.

💡Coordinates

Coordinates in CNC programming are the specific positions in the machine's workspace where the tool is directed to move or perform an operation. The video script discusses the importance of understanding how to read and write coordinates for precise control of the CNC mill.

💡Drilling

Drilling is a machining operation that involves making holes in a material using a rotating drill bit. In the video, the concept of drilling is used as an example of a task that requires precise CNC programming to determine the exact location and depth of the holes.

Highlights

Introduction to CNC programming for beginners, explaining the meaning behind the coordinates and codes used in CNC mill programs.

Explanation of the Cartesian coordinate system and its relation to CNC programming.

Understanding the origin point and how it sets the reference for X and Y values in CNC programming.

Differentiation between positive and negative values in the X and Y axes based on the direction from the origin.

Division of the coordinate plane into four quadrants and the significance of each for determining coordinate signs.

Clarification on the omission of the plus sign in CNC programs when the value is positive.

Importance of correctly placing the minus sign for coordinates in different quadrants to ensure program accuracy.

Example of how points in different quadrants are assigned X and Y values with appropriate signs.

Illustration of a practical CNC mill scenario involving drilling holes in a block, demonstrating the application of coordinate understanding.

The impact of the origin's position on the X and Y values in a CNC program.

Introduction to the Z-axis and its role in adding depth to the CNC machining process.

Explanation of the Z-axis movement in terms of positive and negative directions during machining operations.

Visualization of how the Z-axis corresponds with the machine head's movement during the drilling process.

Understanding the significance of the Z-axis in determining the depth of cuts and the part's thickness.

Overview of the three axes that constitute a three-axis CNC mill and their relation to the Cartesian coordinate system.

Anticipation of the next video in the series, which will cover selecting coordinates for tool path planning in milling operations.

Transcripts

hello and thank you for watching basic

CNC programming for the CNC mill if

you've ever stood in front of a computer

screen or or a CNC mill and you you

watch the program run and you wonder

what it all means the x's and the Y's

and the G's and the M's then study out

these next few videos where I'll explain

what it all means so if that's of

interest of you then I'm going to go

into the very basics of how a program is

put together and where it all starts so

let's get your pen and paper out and

let's get

started all right so let's talk about

the cartisian coordinate system and how

it relates to CNC

programming all right as you can see I

have drawn two axes here a horizontal

axis being the xaxis and a

vertical line being the Y

AIS now there are points infinitely on

these x-axis in either direction and

also on the Y AIS and of course also

away from these axis anywhere in this

space now what we need to learn today is

depending on what direction we find

these points will either give this these

points A Plus or a minus value and that

is very important to understand because

when you look at a CNC program you'll

see plus and minus values and that is

what we're going to learn

here so where these two axis intersect

we'll call that the origin okay and at

that

point or at that intersection the X and

Y values are

zero

now when we move to the right of that

origin we'll go into an X Plus

direction we go to the left of that

origin we're going to an x minus

Direction when we go up from origin

we'll go into a y+ direction and if we

go down we'll go into a y minus

Direction all right so as you can see

these two lines kind of divide this area

up into four quadrants okay you got a

quadrant here which we'll call quadrant

one you got a quadrant here which we

call quadrant

2 three and

four now depending on which quadrant

we'll find these points and will

determine their plus and minus value all

right so for in instance we have a point

right here and as you can see it is kind

of in line with the three on the xaxis

and also three in line of the Y

AIS now that puts that number in a

quadrant

where all the values are Plus in X and

plus in y as you can see right here so

the X and Y value for that point right

there will be x +

3 y + 3 now right off the bat in CNC

programs if a value is plus there's no

need to put the plus sign next to it

however in this quadrant number two we

also have a point that is at a distance

away in x - 3 and y +

3

so now it is important that we put the

minus next to it so that's how the

program will know that this point is now

located in this quadrant okay so let's

look at quadrant number three again

we're at distance away -3 in X and then

-3 in y

so the x value will be Min -3 and the Y

will be Min -3 and so therefore we put a

minus next to it okay very

important so we got one left quadrant

number four any points found here we'll

have an

X+ value and then a y minus value so

that point is sitting at X3 remember

anything to the right is plus anything

below o the xaxis is

Yus again on this point right here

Quadrant

One X + Y + quadrant 2 x is - Y is plus

quadrant 3 x

-

y- Quadrant 4 x +

Yus so in this example you'll see how

this relates to a CNC mill program the

previous illustration we just drew these

points at a distance away from the

origin right now I've drawn a 8x8 square

and these points represent holes that

we're going to have to drill in a

block now we're telling the machine that

the origin or x0 y0 is in the center of

that

block and so we need to tell the machine

the

coordinates where these holes are going

to be drilled at and obviously this

Square spans all four quadrants so

therefore you're going to have plus and

minus

values and so here I think it's very

easy to see why it is important to

understand plus and minus values

depending on where the origin is located

now let's look what happens when we move

this whole square and move it in this

number one

quadrant all right so here you can see

we have shifted our 8x8 square all the

way into quadrant number

one but in essence we just told the

machine that instead of the origin being

in the middle we're putting it on the

lower left hand corner and so you can

see by looking at the the X and Y values

first of all they're both plus but

they're completely different from what

they were in the previous example and so

it's very important first of all that

when you set up a part in the machine

that you determine where the origin is

and that obviously is going to determine

the X and Y values and the plus and

minus all right so we have talked about

X and Y which which is a flat plane but

obviously there's a third plane which is

the Z plane and that's what we'll

discuss

next all right so here we're still

looking at our 8 by8 square in our X and

Y plane which is a flat plane but

obviously our block that we're going to

be Machining is uh it's got some

thickness so we're going to have to add

a another axis which will give it some

thickness so that will be the Z axis and

you can see it also has a plus and a

minus and that also corresponds with the

head on the machine when the holes are

drill the machine will be moving into a

z minus Direction and then when it

retracts to go back to its home position

it will move into a plus

Direction you can see here that the

bottom of the part is even with

-4 so and the top of the part is even

with the origin so that would be

z0 so here you've learned the three axis

that makes up a three axis C and C Mill

and how the plus and

minuses of the X and Y and Z relates to

the cartisian coordinate system so let's

move on to the next video and let's see

how we pick coordinates to descend line

of a tool as we Mill the outside shape

of this Square