Part of Unit: Dimensioning
Lesson Plan Overview / Details
This lesson will allow follow up to the initial Good Dimensioning Technique assignment. This second assignment has students add all Dimension, Extension, Leaders, Center Lines and Text to a completed drawing. Students will add the items needed for the completion of the assignment according to the rules of the handout " Good Dimensioning Techniques".
- Total Lesson Time
- 45 - 55 Minutes
California Career and Technical Education Standards
- ED.C.C3.2 Understand the degree of accuracy necessary for engineering design.
- ED.C.C6.1 Know a variety of drafting applications and understand the proper dimensioning s...
- ED.C.C6.2 Apply dimensioning to various objects and features.
- ED.FS.11.0 Demonstration and Application
California Academic Content Standards (Reinforced)
- ELA.9-10.R.CAGT.2.6 Demonstrate use of sophisticated learning tools by following technical direction...2
- ELA.9-10.W.2.6a Write technical documents that report information and convey ideas logically an...
- ELA.9-10.W.2.6b Write technical documents that offer detailed and accurate specifications.
- M.7.MG.1.2 Construct and read drawings and models made to scale.11
Objectives and Goals
- Reinforcement of the "Good Dimensioning Techniques" rules.
- Introduce New Symbols and Standards for dimensioning.
- Practice assignments for students to gain a better understanding of placing dimensions and symbols used in industry on a drawing.
- Complete a full size Drawing with Dimensions, Symbols and Lines needed for accuracy.
Activities in this Lesson
- Introductory Activity - Hooks / Set
Once students get into their seats ask the class " What type of jobs require you to measure or use measurements on a regular bases?" When the students raise their hands to give their answers begin a list on the board. Accept answers for only 5 -6 minutes. Now ask the class "Why is it important in these jobs to measure or use measurement accurately?" Discuss with the class the answers they are giving and this will lead you and them into the lesson at hand. 10 -12 minutes.
- Review and Addition of Dimensioning Techniques - Demo / Modeling
- Ask the class to take out their Good Dimensioning Technique handouts that were given in a previous class.
- Review with them the importance of following the correct processes to place dimensions on a drawing and how jobs and industry will not accept messy or inaccurate work. Remind students that accuracy on a drawing leads to accuracy on building a project which leads to a safe usable product.
- Now hand out the new information on Dimensioning Angles and Arcs. Have the students follow along as you read the information to them. As you are reading show them examples on the board that represent what you are reading. (Have a drawing on the board ahead of time that will allow you to show the examples). Draw the Dimensioning examples on the board for the drawing as you walk and talk the students through the handouts.
- Be sure to allow students to ask questions along the way.
- Keep everything neat and use different colors to represent various parts of the Dimensions.
- Complete the demonstration and ask students if they have any questions in regards to the various Dimensioning techniques.
- EXAMPLE drawings for board attached . AutoCAD 2005 & PDF files.
- Student Dimensioning Assignment - Demo / Modeling
- Passout the Handout labeled "SHIM - Dimensioning with Accuracy " to the class and have them set up and tape down to their drafting tables.
- They must use a Parallel Bar or T-Square and line up the paper with the bottom line on the drawing. This will ensure accuracy horizontally and vertically when using the triangles and other equipment. DO NOT allow them to set up the papers with the bottom edge of the handout in case the handouts were printed slightly out of square with the edges of the paper.
- In order for the students to see the CORRECT DIMENSIONS and
PLACEMENT for the assignment do one of the following depending on
#1 - Have the Teacher Copy of SHIM shown using a Document Camera & LCD Projector. #2 - Use a Transparency of the Teacher Copy of SHIM
#3 - OR give each student a copy of the Teacher Copy SHIM. (not to scale)
- Guide the students through 2 or 3 of the Dimensions and their correct placement on the assignments. Ask if there are any questions and have the students continue on their own or with some assistance from their neighbor.
- REMIND students NOT to darken in any lines until they are absolutely sure of the placement and accuracy of each Dimension.
- Have an assignment taped to the board that you COMPLETED eariler. This will be for the students to view and assist them as they draw the dimensions on their own assignments accurately.
- The students will have the remainder of the period to complete the assignment. If they do not finish they may complete it as homework.
- Checking for Accuracy - Projects
- Once students feel they have completed the assignment neatly and accurately have them perform a self check with a neighbor.
- They should have the neighbor measure their assignment and verbally critique the work done.
- They may also ask you if they may borrow the TRANSPARENCY that you will use to check their papers for accuracy. But they will only be allowed to do this ONE TIME during the course of this assignment.
- Have them do this at your desk or at a designated spot so the Transparency does not grow feet and walk away.
- Assessment Types:
- Projects, Observations, Teacher Made Transparency
- Create a TRANSPARENCY of the completed assignment and use it to check student work for accuracy and placement of the needed dimensioning criteria.
- This will allow you to check papers a little quicker and more efficiently since the transparency will be the assignment that you completed or use the Teacher Copy to create a transparency.