Comparing Fabrication Workflows in CAD to Support Design Reasoning

TL;DR

The paper investigates how guided, side-by-side comparison of fabrication workflows in CAD can enhance design reasoning. It introduces CAMeleon, a browser-based prototype that lets learners import a model, preview and compare up to 16 fabrication workflows, view workflow-specific constraints, and export instructions for fabrication. Through formative expert interviews and a user study with 12 students, the authors show that guided comparison broadens workflow exploration, shifts reasoning from feasibility to goal-oriented criteria, and supports reflective decision-making. The work demonstrates educational potential for cross-workflow fabrication tools while outlining limitations and directions for long-term curricular integration and broader workflow coverage.

Abstract

When novices fabricate, they start by choosing a workflow (e.g., laser cutting, 3D printing, etc.) and corresponding software from a narrow set they know. As they advance their design, another workflow might better suit their intent, but their models remain committed to the original workflow. This prohibits exploration, which fosters informed decision-making. In this paper, we investigate how CAD interfaces can guide exploration and comparison of workflows. Specifically, comparison can advance users' reasoning about design decisions. We developed a prototype interface, CAMeleon, which lets users compare fabrication workflows. Users load 3D models and preview outcomes from different workflows. We hypothesize that presenting alternative outcomes supports exploration and scaffolds informed decision-making. Upon workflow confirmation, CAMeleon allows users export both machine and human instructions for the chosen fabrication workflow. We interviewed seven fabrication educators to understand how such tools can be integrated into teaching and to demonstrate how we adjust our tool based on their insights. In user evaluation (N = 12), guided comparison helped participants consider a broader range of workflows, reflect on trade-offs, and experiment with new ways of planning.

Figures (21)

• Figure 1: Example outputs designed using CAMeleon and fabricated using a range of machines, showing how the same model behaves across different fabrication workflows, each with distinct material and structural characteristics.
• Figure 2: Workflow selection: (a) Alex imports the stool in CAMeleon, (b) workflows are constrained by available tools, (c) sidebar with swatches and keywords for each workflow, (d) four workflows that Alex selects to compare.
• Figure 3: Comparison interface (a) side-by-side view of four candidate workflows, (b) 3D printing workflow showing print time estimates and size warnings, (c) the hot wire foam cutting workflow and assembly process, with material properties indicating limitations, (d) wire forming showing structural specifications and strength characteristics, (e) epoxy laminating presenting strength and finish characteristics.
• Figure 4: Epoxy Laminating workflow execution. (a) Alex laser-cuts the SVG files, (b) assembles and glues the pieces, (c) sands the assembly for surface preparation, (d) applies a layer of epoxy resin to seal and protect the surface, (e) completed stool.
• Figure 5: Original interlocking model designed for laser cutting by Bailey, which is shown alongside its voxelized reconstruction and alpha-shape reconstruction in CAMeleon.