How thick is one of the hairs on your head? Could it be measured accurately with a standard inch scale? If the smallest increment on an inch scale is 1/6 inch, then 20 average size human hairs could fit within the space of a 1/16 inch gap. The required degree of accuracy needed is dependent on the application. If you were to build a home, a standard inch scale is perfect for laying out walls and locating window openings. A dial caliper is a precision measurement tool that is often used in the design and manufacturing of consumer products, and is, perhaps, the most common of all the precision measurement tools. Engineers, technicians, scientists and machinists all use dial calipers every day to assist the processes of analysis, inspection, engineering design, reverse engineering and manufacturing.
In this activity, you will use your knowledge of technical drawings and dimensioning to interpret which part features must be measured and recorded. You will then use a dial caliper to perform multiple types of measurements of the actual mass-produced part to the nearest thousandth of an inch (0.001 in.).
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Number 2 pencil
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Engineering notebook
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Dial caliper
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Automoblox
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IED – Activity 3.4a Making Linear Measurements (Automoblox PREVIEW) – Page 1

1. Form teams under the direction of your teacher to measure and document an Automoblox.
2. Disassemble the Automoblox assigned to your group.
3. Divide the parts to be measured and documented among your group.
4. Sketch orthographic drawings with the dimensions that must be made for each part in your engineering notebook.
5. Make the required measurements and document this on the orthographic drawing. Note that the dial caliper is designed to make measurements in four ways.
Part to Measure Outside Measurement
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IED – Activity 3.4a Making Linear Measurements (Automoblox PREVIEW) – Page 2

Inside Measurement Depth Measurement
6. Sketch, measure and document the remaining assigned parts.
7. Exchange one part with a group member.
8. Sketch orthographic drawings with the dimensions that must be made for this part in your engineering notebook.
9. Make the required measurements and document this on the orthographic drawing.
10. Compare the dimensions of the exchanged part with the student who documented the original dimensions.
11. Document the reasons for the measurement discrepancies and indicate the decision of the final measurements.
12. Submit your engineering notebook for teacher evaluation.
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IED – Activity 3.4a Making Linear Measurements (Automoblox PREVIEW) – Page 3

1. How has this activity changed the way that you plan to measure and document a part?
2. What additional tools may have helped to measure these parts?
3. Choose one of the parts that you measured. Measure at least five of the dimensions of your part using a standard ruler and record the measurements in brackets next to each caliper measurement. Which measuring devise (the caliper or the ruler) provides the best measurements? Why?
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IED – Activity 3.4a Making Linear Measurements (Automoblox PREVIEW) – Page 4