Knurling (reading and math in CTE)

Objectives: Students should be able to:

• Set up a lathe to perform a knurling operation.
• Successfully knurl a part using the given instructions.

Materials/Resources Needed:

• Measuring kit
• Drop punch piece 2 turned to correct diameter
• Lathe
• Knurling tool
• Knurling instructions handout
• Computer with projector

Anticipatory Set

• I will ask students what they think the purpose of a knurl is?

Discussion:

• I will start off by going through the knurling section on the metals website, including a short video and several slides, and discussing knurling and how it works. I will also show examples of good and bad knurl.
• Students will then be given a knurling sheet with instructions which they will bring to the shop to help guide me to knurling my part.

Model

• After the knurling discussion, I will bring them over to the lathes for a demonstration on knurling for their part. Students will have a set of instructions in which they will guide me through the process of knurling my tap wrench part.

Guided Practice

• If there is time at the end of the demonstration, groups can begin to set up their knurling tools to knurl tomorrow.
• On day two, students who are ready to knurl will begin to knurl their hammer handle using the lathe.

Closure

• Day 1 – We will clean up at the end of the period for approximately 6 minutes.
  • Questions to ask prior to leaving
    • Why does the diameter of the piece INCREASE after knurling?
    • Why does the blueprint call out for such a large tolerance when knurling?

• Day 2 – We will clean up the lab approximately 6 minutes before the end of class.
  • What types of issues arose when knurling and how can you fix them?

Check for Understanding

Students will be assessed based on informal observation on my part as well as the project rubric which contains a knurling section. Not all students work at the same pace so this will take place over the next couple of days as students reach and complete this step in their projects.

Independent Practice

Knurling is often used in many functional parts in manufacturing, especially in the tooling arena. If students complete the progression of metals classes, they will be knurling for various NIMS and TMA projects in the future.