Lesson Overview
Students build on Shapr3D fundamentals by mastering precision sketching techniques and geometric constraints. This lesson shifts focus from basic shape creation to designing with intent — using exact dimensions, sketch constraints (horizontal, vertical, tangent, coincident, concentric), and construction geometry to create controlled, parametric sketches. Students learn how constraints make designs predictable, editable and manufacturing-ready, then apply these skills to model a precisely dimensioned mechanical part (a mounting bracket or similar functional component). The lesson bridges freeform exploration from L1 with the engineering precision required for real-world design work.
Learning Objectives
By the end of this lesson, students will be able to:
- 1Explain why precision sketching matters in engineering and manufacturing contexts
- 2Create sketches with exact dimensions using the dimension tool and numeric input
- 3Apply geometric constraints (horizontal, vertical, coincident, concentric, tangent) to control sketch behaviour
- 4Use construction lines and reference geometry to build accurate sketch frameworks
- 5Identify under-constrained, fully constrained and over-constrained sketch states
- 6Model a functional mechanical part that incorporates multiple constrained sketch features
- 7Edit dimensions post-creation to demonstrate parametric design behaviour
Singapore Curriculum Alignment
Aligned to MOE Design & Technology (Upper Secondary): design communication, working drawings and dimensioning conventions. Supports the Applied Learning Programme (ALP): precision engineering, design for manufacturing, and computational thinking through parametric design principles.
Prior Knowledge Required
- Completion of Shapr3D Lesson 1 or equivalent experience with basic sketch and Push/Pull
- Comfortable navigating the Shapr3D workspace and using touch/pencil gestures
- Understanding of basic 2D geometry (parallel, perpendicular, tangent concepts)
- Familiarity with millimetre measurements and basic dimensioning concepts
Materials & Resources
| Item | Quantity |
|---|---|
| iPad with Shapr3D installed (free education license) | 1 per student or pair |
| Apple Pencil (essential for precise sketching and constraint selection) | 1 per student |
| Teacher iPad with screen mirroring to projector/Apple TV | 1 |
| Shapr3D student account | 1 per student |
| Engineering drawing reference sheet with dimensioning conventions | 1 per student |
| Printed constraint types quick-reference card | 1 per student |
| Optional: 3D printer and digital calipers for verification | If available |
Safety Notes
- Maintain good posture during extended precision sketching — fine motor control work can cause hand strain
- Encourage students to rest hands periodically, especially during long constraint sequences
- Digital calipers have sharp tips — handle with care if used for measurement verification
- If 3D printing student parts, follow all printer and post-processing safety protocols
- Keep iPads on flat surfaces when not actively sketching to prevent accidental drops