[DL64] Model Evaluation and Advanced Sketching

M3D DesignLab DesignLab Grade 6
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Session 4: “Model Evaluation and Advanced Sketching”

Architect:
Syed Shayaan Haider - Markhor3D

Session Overview

In this session, Grade 6 students will first evaluate their 3D printed models, discussing how well their digital designs translated into physical objects. They will reflect on any differences, identify areas for improvement, and consider adjustments needed for stronger, more efficient designs. In the second half, students will refine their sketches in OnShape using advanced features. They will learn how to apply fillets and offsets—tools that allow you to round or bevel corners (fillet) and create parallel outlines (offset) by selecting a corner and specifying a radius or distance. These techniques will help create smooth, durable designs that are ready for the next steps in modeling and extrusion.

Placeholder for printed model evaluation image: [Google Image Search “3D printed model evaluation”]

Learning Objectives

By the end of the session, Grade 6 students will be able to:

  • Evaluate Printed Models: Examine their printed objects for features such as layer quality, wall thickness, and dimensional accuracy.
  • Reflect on Design Translation: Discuss what worked well in their designs and what areas could be improved.
  • Apply Advanced Sketching Techniques in OnShape: Use OnShape’s fillet and offset tools to refine sketches by selecting corners, setting radii (for fillets), or distances (for offsets) to create smooth or beveled edges.
  • Enhance Model Durability: Understand how adding fillets and offsets can reduce stress concentrations and improve the strength of a design.
  • Prepare for Future Extrusion: Create precise, closed sketches that are ready to be extruded into 3D models in upcoming sessions.

Teaching Aids

Visual Aids:

  • Placeholder: [Google Image Search “3D printed model evaluation”] – Examples of printed models highlighting key features.
  • Placeholder: [Google Image Search “Onshape fillet tool”] – Screenshot or video demonstrating how to apply a fillet in OnShape.
  • Placeholder: [Google Image Search “Onshape offset tool”] – Example of using the offset tool in OnShape.
  • Placeholder: [Google Image Search “Onshape advanced sketching”] – Images showing refined sketches using fillets and offsets.

Required Equipment:

  • Computers or Tablets:
    • One per student or pair, with OnShape logged in and access to their design files.
  • Interactive Whiteboard or Projector:
    • For live demonstrations of evaluation and advanced sketching techniques.
  • Printed 3D Models:
    • Each student’s printed design for hands-on evaluation.
  • Notebooks and Pens:
    • For students to record observations and ideas for improvement.
  • Assistants or Volunteers:
    • Additional support to guide students through both evaluation and OnShape operations.

Structure and Lesson Plan (Total Time: 60 minutes)

1. Model Evaluation (25 minutes)

  • Examine Printed Models (15 minutes):
    • Observation and Discussion:
      • “Take a close look at your printed model. Note the layer lines, the quality of the top and bottom layers, and the wall thickness. Use a ruler or caliper to measure key dimensions.”
      • “Discuss with your group: Does the printed model match your original design? What differences do you see, and where could improvements be made?”
    • Identifying Issues:
      • “Look for unconnected parts or leftover support artifacts that might weaken the model.”
      • “Consider whether the design has enough material in critical areas or if any parts seem too thin.”
    • Teacher Questions:
      • “What do you think might be causing any discrepancies between your design and the printed object?”
      • “How could changes like thicker walls or smoother edges improve your design?”
  • Record Observations:
    • Students take notes on the strengths and weaknesses of their printed models and prepare ideas for design refinements.

2. Advanced Sketching in OnShape (30 minutes)

  • Introduction to Fillets and Offsets (10 minutes):
    • Fillets:
      • “In OnShape, you can apply a fillet to a corner to round it off. This helps reduce stress on sharp corners and can make your part stronger. To add a fillet, select the edge you want to round, choose the fillet tool, and set a radius for the rounding.”
      • Placeholder: [Google Image Search “Onshape fillet tool”]
    • Offsets:
      • “Offsets create a parallel copy of your sketch boundary at a fixed distance, which can help you build borders or layers into your design. To use the offset tool, select the geometry in your sketch and specify the offset distance.”
      • Placeholder: [Google Image Search “Onshape offset tool”]
    • Discussion:
      • “Why might rounded edges (fillets) and beveled or parallel outlines (offsets) improve the strength and appearance of a design?”
  • Demonstration and Hands-On Practice (20 minutes):
    • Step-by-Step Demonstration:
      1. Open a Sketch:
      • “Select one of your sketches from a previous session.”
      1. Apply Fillets:
      • “Click on a corner of your sketch. Use the fillet tool to set a radius (try 2–3 mm) and round the corner. Notice how the sharp edge becomes smooth.”
      1. Apply Offsets:
      • “Select the entire closed sketch and use the offset tool to create a parallel outline. Set a small offset (about 1–2 mm) to create a border around your shape.”
    • Hands-On Practice:
      • “Now, take your own sketch and try applying a fillet to one or two corners. Then, use the offset tool to add a border. Adjust the parameters until you’re satisfied with the result.”
      • “Try to exclusively extrude the new formed geometry. How is it different? What kind of things can you make with this?”
    • Teacher and Assistant Support:
      • Walk around to provide help with using the fillet and offset tools.
      • Encourage students to experiment with different radii and offset distances to see how it changes the strength and appearance of their design.

3. Sharing and Feedback (5 minutes)

  • Student Presentations:
    • “Would anyone like to show their refined sketch and explain how you used fillets or offsets to improve your design?”
  • Peer and Teacher Feedback:
    • “I really like how you rounded your corners—it makes the part look stronger and more professional.”
    • “Your offset adds a neat border that could be useful for creating layers in future designs. Great job!”

4. Conclusion and Next Steps (5 minutes)

  • Session Summary:
    • “Today, you evaluated your printed models and learned advanced sketching techniques in OnShape. You applied fillets to round off sharp corners and offsets to create parallel borders, which are important for improving strength and preparing your designs for extrusion.”
  • Preview Next Session:
    • “In our next session, we’ll use these refined sketches and extrude them into 3D models, building on the precision and techniques we learned today.”
  • Closing Encouragement:
    • “Excellent work today! Your attention to detail and willingness to refine your designs will lead to even better models. Keep up the great work, and get ready to bring your sketches into 3D in our next session!”

Glossary

  • Fillet: A rounded edge added to a sketch to reduce stress on sharp corners.
  • Offset: A tool that creates a parallel copy of a sketch or shape at a set distance.
  • Closed Sketch: A 2D drawing where all lines connect to form a complete boundary, necessary for extrusion.
  • DFAM (Design for Additive Manufacturing): Guidelines that help create 3D models that print successfully and are durable.
  • Precision: The quality of being exact and accurate in measurements and design.

For suggestions, improvements, and corrections, feel free to reach out at shayaanhaider@gmail.com