ME 2024 – 3D Printer Product Archaeology Exercise

Submission: team worksheetDue: by the following class meeting

CRN_______ Team________

Do NOT add a team member’s name if they are absent or did not contribute to the solution to this exercise. It is a violation of the Virginia Tech Honor Code to do otherwise.

Member 1________________________________

Member 2________________________________

Member 3________________________________

Member 4________________________________

Important Dissection NoteTo ensure that your 3D Printer and Extrusion Assembly can be successfully reassembled (and thus be able to be used by future students), please carefully follow the dissection steps below. Only disassemble the components that are listed in the instructions.

Part 1: Preparation for GSEE Considerations As you disassemble this object, keep in mind the product archaeologist’s view. What are the global, social, environmental, and economic impacts of this product? How did these four contexts influence the design of this product and its potential uses?

We begin by comparing the differences between “mass production” (which is the basis of almost all manufacturing) and “mass customization” (which is much of the promise of 3D printers). Throughout the exercise, consider how device functions relate to GSEE dimensions.

Part 2: Begin a Print

1. Using the Interface Board, press the up/down buttons to select “Start Build” and press the “OK” button until you get to the list of printable files on your SD card. 

2. Use the up/down buttons to find your desired file and press the “OK” button. 3. The MakerBot will move and begin heating. The MakerBot is heating up when the screen shows the

temperature values as “/225” and “/130”, as these are the respective temperatures (Celsius) that the extruder and build platform must heat to before the build begins. Once these components are heated, the machine will begin printing the part raft (the base on which the part will be printed), and will then print the part.

Part 3: Part Identification

4. As the printer is working, label its components (circled in red) in Figures 1-3. Consult the “MakerBot Electronics Schematic” handout, which provides an overview of all of the electrical connections between the 3D Printer’s components (which are also listed in Table 1). Consult the exploded view schematic for additional guidance.

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Table 1. 3D Printer Components1. Heated Build Platform 6. X-Axis Stepper Motor2. Stepstruder Stepper Motor 7. Y-Axis Stepper Motor3. Extruder 8. Z-Axis Stepper Motor4. Safety Cutoff 9. X-Axis Min Endstop5. ATX Power Supply 10. Y-Axis Min Endstop

11. Z-Axis Max Endstop

Figure 1. Front view of MakerBot ToM

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Figure 2. Side view of ToM

Figure 3. Close-up of X-Y Plane

Figure 4. ToM Electronics and Controllers (located at bottom of case)

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Part 4. Motion Control Analysis

5. Describe how the 3D Printer translates G-code instructions from the SD card into physical motion of the extrusion head. (Hint: follow the flow of the electrical signals)

6. Describe how each of the three axes are moved (i.e., what provides/guides/controls the motion?)

7. What is the purpose of the endstops?

Part 5. Motion Analysis

8. As the printer continues to operate, turn your attention to the separate Stepstruder assembly. This assembly features a MK6 extrusion head. (the printer is using an updated MK7 extrusion head)

9. Disassemble the assembly by unscrewing (only) the four screws highlighted in red in Figure 5. This will separate the motor mechanism and fan from the rest of the extruder. (This might require a significant tug, as the bearing is press-fit into the assembly.)

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Figure 6. Close-up of notched Stepstruder motor shaft

Figure 5. Stepstruder Assembly Figure 7. Extrusion nozzle & thermal core (with insulation removed)

10. How does this Stepstruder extrusion assembly work? i.e., describe how solid polymer filament is extruded as a thin polymer melt.

11. Why is the gear on the shaft of the Stepstruder stepper motor notched (Figure 6)?

12. What function does the black thumb screw serve?

13. What function does the thermostat (MakerBot Electronics Schematic) serve?

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14. What function does the safety cutoff switch serve?

15. What function does the fan mounted on top of the extruder motor serve?

16. Why is the build platform heated? (Hint: what happens to plastic when it cools and solidifies?)

Part 7. GSEE Analysis

17. How much waste material has your machine produced thus far in the build process? How does this compare to “subtractive” manufacturing techniques (e.g., mill, lathe, etc.).

18. What are potential advantages of 3D Printers over traditional fabrication and manufacturing?

19. What are potential disadvantages or limitations of 3D Printers over traditional fabrication and manufacturing?

20. What new societal challenges does 3D printing pose (i.e., will it “change the world,” and in what ways)?

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