f13 lab 3 engineering drawing

7/27/2019 F13 Lab 3 Engineering Drawing

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Lab 3: Engineering Drawing

Objectives

Learn how to draw a dimensioned engineering drawing (technical drawing) Practice using three orthographic views to represent a 3D object in 2D Practice using proper measuring tools (calipers, rulers) to measure dimensions of 3D objects.

Pre-Lab Questions

Answer the following questions in your lab notebook before you come to the lab.

1. In an orthographic multi-view drawing, what are the three views we use to represent a 3Dobject?

2. On a multi-view drawing, how should the three views be aligned? Show using a simple labeledsketch.

3. How do you represent hidden lines on an orthographic drawing?Introduction

An effective way of communicating engineering designs to others is through the use of detailed

sketches. In fact EVERY manufactured item designed by an engineer has a detailed drawing,

accompanied by engineering specifications. In this lab, you will create multi-view drawings of some

simple 3D objects and use your drawing skills to communicate a bridge design for another group to

build.

Lab Procedure

Part 1: Creating a Multi-View Drawing for Simple Objects (Individual Work)

Your task is to work as an individual and create dimensioned engineering drawings in your lab

notebook for the objects provided or shown below. Make sure your drawings are neat, and use the drafting tools provided to create straight lines,

round circles, etc.

You should include three views and label the dimensions. Indicate the units somewhere on thesketch.

The three views should be properly aligned.Part 1a: Creating an Orthographic Multi-View Drawing of a 3D object

Create a dimensioned drawing of the snap cubes object provided. You may use rulers, tape measures,

etc. to measure the dimensions of your object (note that all the snap cube blocks are the same size).

Part 1b: Creating an Orthographic Multi-View Drawing from a 3D drawing

Create a dimensioned multi-view drawing of each of the 3D drawings below. The front side ofeach

object is indicated by the arrow. The gridlines shown on the objects below indicate their size: each

square is 1x1 and the distance between 2 parallel gridlines is one inch.


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Once all of your team members have completed their sketches, compare your drawings. Suggest ways

to improve each sketch and make appropriate corrections to your sketches.

Part 1c: Creating a 3D Object from an Orthographic Multi-View Drawing

As a team, use the snap cubes to build the object shown in the sketch below. Once you are done,compare it to the correct object under the box at the front of the class. Make sure to take a picture of

your creation and include it in your lab notebook.

Part 2: Designing a Bridge (DO NOT MOVE ON TO THIS ACTIVITY UNTIL DIRECTED TO DO SO)

In this part, you should work as a team and design the lightest bridge possible that will support as

heavy of a vehicle as possible. The bridge must be able to span a 2 foot gap and cannot be attached tothe tables. The vehicle (which is available for you to look at) must be able to roll across your bridge.

You may only use the provided materials in your design. Your team is NOT building your design!

You will have 10 minutes to discuss the design as a team. Once preparation time is up one person will

begin to produce a dimensioned engineering drawing that will be used to build your design. Every 5

minutes you must switch who is doing the drawing and everyone must have a turn drawing before

(1) (2) (3)


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anyone is allowed to repeat. While one person is drawing, the other team members should be

ensuring that the drawing is clear and appropriately describes the design.

Your drawing should:

Be drawn on the sheet of engineering paper provided Be drawn neatly, using the drafting tools provided to create straight lines, round circles, etc. Include the three views required to define the bridge your team has designed. Make sure the

three views are properly aligned.

Include all dimensions necessary to define the bridge design (be sure to indicate unitssomewhere on the drawing)

You may include notes on the drawing to indicate materials.After lab, make photocopies of your engineering drawing for everyone in the group and include them

in your lab notebook.

Part 3: Building Bridges

For this part, you need to give the engineering drawing of your bridge to the team that will build yourdesign (follow instructor instructions). Once you receive a drawing from another team, you should

build the bridge to the specifications of the drawing. Do not get clarification from the design team. If

something is unclear, make note of it, and make your best guess. You will provide feedback to the

design group after you construct the bridge. Once your design is built and returned, take a picture of it

(you will include this in your lab notebook), and get feedback about the effectiveness of your drawing

from the build group.

Part 4: Testing Bridges

Each team will have a chance to demonstrate/test their design in front of the class. Your team will

have 2 runs. As a team you can choose how much weight to add to the car for each run. Each run will

start by pulling the car to the middle of the bridge, then the car will rest at the center for 5 seconds,

and then finish by pulling the car the rest of the way through. A successful run is one in which the

bridge does not fail. The winning team will be the one that has the largest load/weight ratio. Be sure

to record the following in your notebook: mass of your bridge, the loads (mass) that were tested,

calculated load/weight ratio, and observations about how your bridge performed.


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Post-lab Questions:

1. Of the four drawings shown below, which drawing (set of 3 orthographic views) is aligned correctly?

2. Dimension Ain the top view shown below is the dimension between theA. left & right side (width) B. Bottom & top (height) C. Front & back (depth) D. Top and side

3. Complete the 3 view drawing for the 3D object shown below by drawing the right side view

4.

Which cube structure (A, B, C, or D) does the 3 view drawing on the left represent?0

Front


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Lab Deliverables

Make sure your lab notebook is complete, following the format below, before the start of next weeks lab.

Lab Notebook Format

Name:

Title of lab Date and Time

I. Pre-lab QuestionsAnswer the pre-lab questions.

II. Lab DescriptionProvide a brief description of the lab using your own words.

III. Measurements and Data Part 1: Include dimensioned drawings of the simple objects including top, front, and side views,

following the instructions. Make sure the three views are properly aligned. Make sure to

include a printout of a photo of the structure you built inpart 1c

Part 2: Include a copy of the dimensioned engineering drawing of the bridge that yourteam has designed including top, front, side views. Be sure to include all necessarydimensions and appropriate units. Make sure that the three views are properly aligned.

Part 3: Attach a printout of the photoof the bridge that was built based on yourteams design (gray scale is acceptable).

A. Part 4: Include notes from your bridge testing including the mass of your bridge, theloads tested, and your best load/weight ratio.

IV. Post-lab QuestionsAnswer the post-lab questions.

f13 lab 3 engineering drawing

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