Tags

Lesson Plan Industry Sector
Manufacturing & Product Development

Lesson Plan Originally Created By: Lance Tatro

Tooling the Mill by Lance Tatro

Part of Unit: Tooling Descriptions

Lesson Plan Overview / Details

Students will learn about mill cutters and lubricating fluids for machine finishing using the mill.

Lesson Time

1 Class Period
85 Minutes

Objectives and Goals

  • The student will be able to compare and contrast different cutting and finishing tools for the mill.
  • The student will be able to identify the different materials used to make mill cutters.
  • The student will be able to understand feed rates and necessary speeds for proper cutting.
  • The student will be able to understand lubricating fluids and which fluid is best for a given cutting situation.

Vocabulary Terms and Words

Vocabulary Words and Terms:

1.     Feed Rate: The unit distance divided by a time scale that a tool travels while machining. Usually the unit distance is "inches" and the time scale is "minutes". The resultant rate is then expressed as "inches per minute" (or i/m or IPM)

2.     High Speed Steel: Refers to steel that can cut at a higher speed than other tool steels.

3.     Cobalt: A tough lustrous silver-white magnetic metallic element that is related to and occurs with iron and nickel and is used especially in alloys.

4.     Carbide: In the machine shop this usually refers to cutting tools made of cemented tungsten carbide and cobalt.

5.    Flute: Refers to the undercut of the cutting edges of multi-edged end mills, reamers, drills, and other cutting tools.

Note: Increasing the number of flutes from 2 to 3 or more improves your surface finish at equivalent feed and speed

Activities in this Lesson

  • Anticipatory Set: - Hooks / Set

    Teacher will reflect on the Machining Lesson, and prompt students to reflect on the five main machine processes and the machines that are commonly used for finishing metals.

    Teacher will call on non-volunteers to name one of the machining processes, and some of the primary features about that machine.

    Continue to call upon students until three or four machines have been named.

    Teacher will say: Let’s talk about the milling machine. We know what a milling machine is, and we have learned about the various types of milling machines. When we generally think about this machine, aside of the machine itself, can anyone think about any thing else that might influence the cutting process?

    Teacher will use the whiteboard to list all the student suggestions. If the students struggle to list any potential influences, then provide an example. “What about how fast the material is fed across the cutter? Would that have an effect on the finishing? This called the feed rate.

  • Instruction: (during)
                              
    Using PowerPoint Presentation

    Teacher will use the presentation to introduce the lesson and explain the vocabulary words.

    In order for the lesson to be effective, students will need to become familiar with the vocabulary words/terms.

    •  Feed Rate
    • High Speed Steel
    • Cobalt
    • Carbide
    • Flute

    Teacher will explain the words and then ask the students to pair share with another student the meaning of one of the words.

    Teacher will check for understanding (random call, sticks, etc.)

    Teacher will explain the lesson objectives.

    By the end of this lesson, you should be able to:
    o    Compare and contrast different cutting and finishing tools for the mill.
    o    Identify the different materials used to make mill cutters.
    o    Understand feed rates and necessary speeds for proper cutting.
    o    Understand lubricating fluids and which fluid is best for a given cutting situation.

    Teacher will introduce the seven most common endmill cutters.
    HHS, Cobalt, Carbide, Coated, End, Single-end and Double-end.  

    Teacher will explain how different needs are met through the various cutter designs.
    Roughing, Ball nose, Keyway cutters, Dovetail, V-cutter, Concave and Fillet.

    Teacher will explain the importance of speed and feed rate, and how to calculate the proper speed and feed rate for the material and cutter being used.
    RPM = (CS x 4 ) / D , whereas Feed = RPM x Chip load per tooth x Number of teeth on cutter.

    Teacher will display and explain the machine ability chart for speeds and feed. This is a chart that displays the speeds and feeds for common materials.

    Teacher will explain the various “specialty” cutter used in milling. With each picture displayed, the teacher will explain the physical characteristics and the cutting characteristics of each cutter.

    • Instructional PowerPoint [ Download ] This Presentation will assist the lecture, and allow students to visualize the lesson information.
  • Guided Practice - Lab / Shop

    Guided Practice

    Teacher will display the website http://www.jjjtrain.com/vms/cutting_tools_mill/cutting_tools_mill_04.html

    Teacher will say here you will find information on cutting lubricants. You will need to read through the provided material and answer the following questions:

    • What is best used when cutting cast iron?
    • What is the disadvantage of using synthetic fluid when cutting polypropylene plastic?
    • What are emulsions?
    • What are some of the problems with using water as a cutting/cooling fluid?


    Give the students three to fifteen minutes to do this. Students who understand quickly can help those that are slower with this part of the assignment.

    After 15 minutes, allow student to collaborate their answer with a close by peer to confirm the selected answers. Let the students work on their research and monitor them as they work.

    Teacher will provide the correct answers using the presentation.

  • Summary Review - Closure

    Review:


    What is the least expensive material used for mill cutters? HSS

    How does a rough cutter reduce horse power usage? Their flutes are truncated to break chips thus reducing horsepower requirement.

    What is RPM? How does it apply to mill cutting? Revolutions Per Minute. Defines the speed of the spindle (cutter speed).

    Teacher will call on random students to provide answers.

  • Extended Practice   (after)

    Teacher will give the students the worksheets

    Teacher will say:

    • "Use the provided worksheets to help you determine what you have learned".
    • "Look at each of the pictures and provide the type of cutter that it is, what it is used for, and any negatives that might be associated with that cutter".
    • "You will be graded on your accuracy and appropriateness of the information you provide".


    Ask the students to look over the worksheets and ask if they need any clarification on what is expected, or if there is any information that is unclear.
                   

    • Worksheet for Mill Cutters [ Download ] Students will use the assignment prompts to answer questions

Assessment

Assessment Types:
Observations, Worksheet,

Evaluation: 

       
Informal evaluation:

  • Teacher will visually and verbally check throughout the lesson for comprehension.
  • Teacher will walk through during the research process and check to see if students are progressing compared to desired outcomes.  
  • Teacher will collect and check handouts for comprehension and provide additional instruction upon need.  
     
  • Mill Cutter Handout Answer Key Mill Cutter Handout Answer Key [ Download ] This is the answer key for the student handouts.

Enrichment/Enhancements

Intervention Strategy:

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.

Enrichment Strategy:

Students will use the following website to discover information on tool holders.

Mill Machine Tool Holders
http://www.jjjtrain.com/vms/library.html