Bonus Print - Guided Extension

Estimated time: 3-5 hours

Learning Objectives

• Apply scaling and simple modifications to an existing model
• Verify multi-part prints and manage print constraints
• Document design changes and reproduceable print settings

Materials

• Online repository access, slicer, printer, filament

Step-by-step Tasks

1. Choose a model from Thingiverse or Printables and note the original dimensions.
2. Decide on a purposeful modification (scale, add mounting holes, combine parts) and explain why.
3. Apply changes in OpenSCAD (or by scaling in the slicer) and record the new dimensions.
4. Slice and print all parts in one session when possible; log print times and filament used.
5. Create a short construction note and photograph the assembled result.

Probing Questions

• What motivated the modification and who benefits from it?
• How did scaling affect tolerances or assembly fit?

Quiz - Bonus Print (10 questions)

1. What is one risk when scaling a model up or down? (short answer)
2. Name two checks to perform before printing multi-part models. (short answer)
3. How should you record filament usage? (short answer)
4. Why document construction steps? (one sentence)
5. What is one visual sign a part needs more infill? (one sentence)
6. True/False: Scaling a model uniformly (proportionally) in all three dimensions will preserve the original fit tolerances perfectly. (Answer: False - because tolerance stack-up and printer behavior can change)
7. Short answer: Explain the difference between scaling a model in the slicer versus modifying the OpenSCAD code to scale a design. Which approach is more reproducible?
8. Practical scenario: You want to scale a model from 10 cm to 25 cm (2.5x scale). What should you check regarding print time and support material before committing to the print?
9. Multiple choice: When assembling multi-part prints, what should you test first? (A) The final assembly (B) Individual part dimensions, then pairwise assembly (C) Skip testing - Answer: B
10. Reflection: Describe how documenting your modifications (scaling factor, OpenSCAD code changes, filament type, print settings) enables other students to reproduce your design and iterate on it further.

Extension Problems (10)

1. Create a small assembly guide with tactile cues for non-visual users.
2. Produce two scaled variants and compare required print time and fit.
3. Modify a part to include snap-fit connectors and document fit tolerances.
4. Add simple labeling to parts using embossed text in OpenSCAD.
5. Publish your variant and short build notes to the class repo and review two peers’ submissions.
6. Build a complete variant library: create 5+ variations of your bonus print; document parameters, reasoning, and use cases.
7. Design a variant optimization process: compare variants by cost, print time, quality, and functionality; justify your “best” choice.
8. Create a parametric master file that generates all variants automatically; test parameter ranges and edge cases.
9. Develop a variant documentation and sharing system: create a portfolio with photos, specs, and instructions for each variant.
10. Write a “remix and iterate” guide: explain how future students can modify your designs, what parameters they should change, and how to test improvements.