Part of Unit: Computer Numerical Control (CNC) Machining
Lesson Plan Overview / Details
Students will participate in an activity that will help them understand CNC programming and how machines read programmed information.
- 1 Class Period
- 85 Minutes
California Career and Technical Education Standards
- MPD.C.C1.1 Interpret scaled machine tool and materials forming prints; gather design and ma...
- MPD.C.C1.3 Use current information technology ideation and design process systems in the ma...
- MPD.C.C7.3 Use computers to design and produce machined and formed products, write numerica...
- MPD.C.C8.2 Understand the importance of maintaining documentation for machining and forming...
- MPD.FS.10.5 Complete a comprehensive working sketch and drawing of a product to be produced.
- MPD.FS.10.6 Apply the design process in the development, evaluation, and refinement of a man...
- MPD.FS.4.5 Understand manufacturing-related concepts and the applications of technological ...
California Academic Content Standards (Reinforced)
Models listed in PowerPoint or Projection
Computer with PowerPoint software
1. Graph paper (8.5 x 11)
3. Inch ruler
Objectives and Goals
- Explain how a computer controlled machine (CNC) operates.
- Explain the relationship of x, y and z coordinates.
- Explain how they are used to create a product on a CNC machine.
Activities in this Lesson
- Connecting to Prior Knowledge - Hooks / Set
Teacher will reflect on the student's use of absolute value entries to draw in AutoCAD, or their use of coordinate system in Algebra to draw upon prior knowledge. Call upon students to provide examples of how this was done.
- Guided Exercise - Demo / Modeling
Use the overhead sheets as the students progress through the lesson to model the expected outcome
Teacher will introduce the lesson, and say: Today we are going to do a simple exercise using x and y coordinates to create a design of your choice. Using your graph paper and a ruler, draw a 4 x 6 inch rectangle on the sheet.
Teacher will: Create a large version of the 4 x 6 on your white board to assist the students.
Show Step 1: Using Models Sheet
Teacher will say Number each of the lines on the 4 x 6 rectangle from 0 to 24 across the bottom or the horizontal axis (X axis) of your rectangle, and label the vertical axis on the left hand side (Y axis) from 0 to 16. Be sure and place your numbers on the lines and not in the spaces. (Show this on your large version on the board.)
Show Step 2: Using Models Sheet
Give the students three to five minutes to do this. Students who understand quickly can help those that are slower with this part of the assignment.
Teacher will say Now that you have created a 4 x 6 rectangle and labeled the lines, create a design inside the rectangle on your sheet. Your initials or some simple words are a good example of what you can create for this assignment. It is important that you use only straight lines for this activity. (Once again, refer to the examples for this activity or the one you created on the board). No curves are allowed.
Show Step 3: Using Models Sheet
Let the students work on their ideas and monitor them as they work. Help them to create only lines for this activity. (Allow 8-12 minutes for this part of the activity.)
Teacher will say Now that you have your design on the rectangle, place a point at the beginning and end of each line segment on your design. (Show the students how to do this on your large example.)
Give students time to mark the points on their assignment. (Allow 5-7 minutes for this part of the activity.)
Teacher will say We are now going to name each point that you marked on your design using the Cartesian coordinate system. Points are named by using coordinate pairs (X, Y). X is always the first number and Y is always the second. This is as we did when we used AutoCAD and we entered absolute values for each of the points on the drawings. Remember X is horizontal (sideways) and Y is vertical (up and down). (You can do your school initials on a white board as an example for your class and show the examples provided of individual letters in block style). Keep this first design simple. Be sure and name all the points on your design. Finish the first letter, and then proceed to the next letter or letters. Name them in a logical order just as if you were completing a dot-to-dot exercise. This is very important.
This part of the activity will take the longest amount of time depending on the complexity of the designs your students create. (Allow 10-15 minutes for this part.)
Show Step 4: Using Models Sheet
Teacher will say CNC equipment uses these numbers and coordinates to cut parts and products for manufacturing. Have any of you ever seen a CNC in operation? (You might let the students talk about this for two or three minutes and then get back on track). Who knows what the Z coordinate might be used for? (Give time for response). Z controls the depth of cut on a CNC machine.
At this point, collect all the papers.
- Models Sheet [ Download ] This sheet will provide examples for students to compare their work to the expected outcomes
- Guided Review - Demo / Modeling
The Teacher will demonstrate model-building techniques while students observe. Ask for one or two volunteers to re-demonstrate in front of peers. Encourage students watching to peer coach and evaluate the student demonstrator on drawing techniques.
Q. How are points named? By a coordinate system (Groupings listed as (X,Y)).
Q. What is the first number, second, third? X position left or right, Y position forward and back, Z position Up and Down of the cutter
Q. Do you need to name all the points on your design? If so, why? Yes, to allow the programmer to assign values to the Points
Q. How does the CNC use the numbers and coordinates? The CNC uses the coordinates to move the cutting tool along a path to remove the unwanted material.
Teacher will call on non-volunteers to provide possible answers
- Extended Practice - Other
Extended Practice: (after)
Students will use this information to develop a usable code as the unit progresses. Or the lesson can be used as a stand alone lesson.
- Assessment Types:
- Rubrics, Observations,
Teacher will observe students during guided practice to assess student understanding of concepts and techniques. Revision/reteach will occur as needed before moving to Independent Practice portion of the lesson.
Teacher will circulate through lab as students work on drawings independently to redirect/reteach as necessary.
Use model Rubric to evaluate the finished student work.
- Rubric for Project [ Download ] Rubric for assessing student understanding of guided work
If the student is not learning, or finding the correct information:
- The teacher will review the instructions, and identify if problem is understanding or procedural.
- The teacher will guide the student on the correct pathway for discovery.
- Student is allowed to receive peer help.
- Student can be assigned a partner.
- Have the students use AutoCAD and insert their designs into the program using the X and Y coordinates to verify the accuracy of their work. This exercise can take the entire class period as students collaborate on this activity.
- Import the CAD drawing into your CAM software. Set the tooling parameters and simulate the cutting of the designs created by the students.
- Actually cut the designs into a .25 x 4 x 6 piece of wood for the students.
- Students can now proceed to more complicated designs if you wish to spend more time on CNC programming.