Activity 9  

CNC Machining  

  

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Reference Guide  

Do NOT write in guide book!!! Table of Contents 

 Project timeline 3  Information Page 4  Description Page 5  Activity 9-1 6  ACtivity 9-2 7  Activity 9-3 8  Programming on the EMCO Mill 10  How to graph your part 13  Activity 9-4 14   

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Project Timeline   

Day 1 - Create your map of the Stem lab area.  Day 2 - Study and make flashcards for the G & M codes  Day 3-4 - Complete your cheat sheet for the CNC Puzzle, and enter  

it into the EMCO Machine.  Day 5 - Look at the Haas workbook and figure out G-41 Cutter  

comp and G-81 Canned Drill cycle.  Day 6 & 7 - Write your code for the CNC Tic Tac Toe Board and  

enter it into the EMCO Machine.   Day 8 - Take turns running the TTT Board.  Day 9 - Clean up              

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Information Page - Activity 9 Activity: CNC Machining Activity Description (100 points) In this activity you will learn the basics of CNC code writing. This will help you understand the basics of machining. You will understand how to set-up a CNC machine, how to write machining codes and how to combine multiple tasks using different cutting tools. This activity will help tie together math, drawings, coding and many of the things you learned to date. Most importantly it will show you some CNC capabilities which helps you to become a smarter designer. CNC code works on the smallest and the largest cnc equipment. Learning Objectives - Resources: Videos: How to load a cnc program into a CNC Mill How to graph a CNC Program How to set machine offsets How to do tool changes To receive credit: Product 9 - A (85%) - Terms and Vocab 9 - B (85%) - Haas workbook packet 9 - C (85%) - EMCO Puzzle worksheet

 

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Activity 9 - Description Activity: CNC Machining Activity 9-1 - Groups

Create a map using steps as measurements to exit our classroom out one door, go to Mrs. Kelty’s desk and return. Constraints are:

● Start at X on our floor ● Must exit one door and return in the other ● Turns must be 90° or a radius turn ● Facing the lockers is Y+ direction ● Make an X,Y coordinate for each change of direction ● Plot these points on a Cartesian Math Chart

Activity 9-2 - Individual

Make a set of flashcards for the G-codes and M-codes that appear in the 1st 5 lines of a program and the last 2 lines. Include G41, G42, G40 and G81, G83 and G99.

Activity 9-3 - Individual

Create a program to make a puzzle. You will use graph paper following the parameters given and draw a puzzle. Once the drawing is approved, you will write a cnc code to make the puzzle, you will enter this into the CNC machine and graph the part. If the graph matches your drawing, make the puzzle out of Renboard.

Activity 9-4 - Individual

After completing Activity 9-3 you will make a tic tac toe board using the skills you learned above. You will need to find and complete the workbook pages for drilling holes, you will also need cutter comp for part of this part. There will also be multiple tools required, so you will need to set Z offsets on multiple tools.

This activity could be the most taxing. You will need to get out of your comfort zone and trust yourself and your skills.  *All info and Data should be recorded in your engineering notebook!  

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Activity 9-1  With a partner, get a piece of graph paper and create a “map” from our room to Mrs. Kelty’s Desk.

Constraints are: ● Start at X on our floor ● Must exit one door and return in the other ● Turns must be 90° or a radius turn ● Facing the lockers is Y+ direction ● Make an X,Y coordinate for each change of direction ● Plot these points on a Cartesian Math Chart

Using G01 as straight lines, G02 as Clockwise arcs and G03 as Counter Clockwise arcs write a step by step instruction how to go from (0,0) back to (0,0). Example: G01 X -25 Y 0;

G01 X-25 Y12;

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Activity 9-2 

Note: The first 5 lines are always basically the same, and the last 2 lines are always the same.

1. Using the Haas Workbook, look up all the G & M codes you don’t know in the simple program above. Record these in your engineering notebook AND make flashcards to memorize these codes.

2. On a small piece of graph paper, draw the part that this program makes and tape

it into your engineering notebook (or just sketch it right into your notebook.

Activity 9-3  You are going to create a simple puzzle with a 3” x 3” piece of Ren Board (pink colored blocks). Follow the set-up sheet below and follow the constraints outlined in the sheet. Below is a Sample of the set-up sheet I provide. Complete the sheet as I have, then write a program to create your puzzle.

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HERE IS A SAMPLE, DO NOT USE THIS, JUST A REFERENCE!

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Here is a program to make the puzzle on page 8. At this point you should know what G & M codes stand for.

This is MY program, your will look a little different, don’t just copy mine. You can type your program in docs or in notepad and save it as a word.doc or on notepad and save it to a flashdrive. You can then copy and paste it into the EMCO. See file Transfer page. You can hand write your program. You will enter this program into the EMCO machine and graph it. Follow the steps below to enter and graph your program.

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Programming the EMCO CNC Mill 

First you need to familiarize yourself with the controls of the EMCO machine.

These are the controls and what they are called.

Also located on pgs. 3-8 in the EMCO Teacher's guide.

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To begin a new program: turn the MODE Dial to Edit, these positions are not named on the dial, but they will show up on the screen in the bottom left corner.

To enter a program type O#### and press and push INPUT key on the Fanuc Keypad.

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You will then have this screen and you will be ready to type your program in. Type in the program using the Fanuc Keypad. At the end of each line type in Insert 2x or EOB (end of block). If you make a mistake change it with the Alter key or you can just remove mistakes with the Delete key. All these are up on the panel, the change keys.

If you are calling up a previous program, push the SOFT KEY that is aligned with the word directory (DIR) as seen below.

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Graphing your program  

This is how we test our program to ensure it is running correctly.

Start by locating the graphing key (at the bottom of the Fanuc Keypad).

Once you hit graph you will need to set up the viewing “window”. Use the following info to set the window size (know the size of the part you’re running”

X – enter the distance you will be going in the X+ direction, add .500” to that.

Y – enter the distance you will be going in the Y+ direction, add .500” to that

I – this is the distance in the X- direction (add .500 additional)

J – this is the distance in the Y- direction (add .500 additional)

You can move from one to the next with the cursor arrows at the bottom of the Fanuc Keypad.

To run the graph, go to the soft key that aligns with the EXEC and press that, then press the soft key that aligns with START.

If the part runs and looks like your drawing you are finished.

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If you get an alarm, you need to figure out the problem and fix it, continue to graph and fix it until you have no more alarms and the part runs ok.

NEVER RUN YOUR FIRST PART WITHOUT THE TEACHER PRESENT AND COACHING YOU THRU THE PROCESS!!!!!!

Activity 9-4 

Use the emco handbook and Haas workbook to help you program the Tic Tac Toe board. This is what I suggest for the TTT board:

Program 1

Write a program (decking/surfacing) to cut the entire top , think of mowing grass, you need to zig zag or circle around until you have covered the whole top. Rules: only cut with ½ the cutter (radius) this is called Step Over.

Program 2

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Write a program (profile) to cut around the perimeter of the part. Read the print and get them dimensions of the part and then write a program to do this. You will want to use a G41 Cutter Comp code to do this. Look in the Haas workbook and follow their examples to do this. Cutter Comp is not difficult, read a little about it before you ask the instructor for help.

Program 3

Write a program for the lines on the TTT board. This program DOES NOT use cutter comp so just follow the lines around until you have cut them all. Straight forward, just plot points and go.

Program 4

Drilling the holes. Again look at the Haas workbook for G83 code and give it a try. I can help you ONLY after you have looked at their example and tried to write it. Enter it into the EMCO and graph it and see what it shows.

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