Fab Lab Rwanda · Group work
3D Scanning and Printing
Our group work focuses on the design rules of the lab printer: what it can bridge, support, resolve and fit together. These limits must come from printed test pieces with a recorded slicing profile.
Printer characterization method
We will identify the printer, nozzle diameter, filament material, slicer and profile before printing. Layer height, temperature, cooling, speed, wall count, infill and support settings affect the result; keeping them together makes each sample reproducible.
Our first pass should use labelled test features at a known scale. We will change one parameter at a time when investigating a failure, then retain the profile that produced the final comparison.
| Feature | Test method | Design decision |
|---|---|---|
| Overhang | Compare marked angles with supports disabled | Which slopes need support or reorientation |
| Bridge | Increase unsupported spans in steps | Practical unsupported span for this profile |
| Thin walls and detail | Compare nominal dimensions with the printed features | Smallest reliable wall and readable detail |
| Clearance and holes | Try mating pairs and measure holes in more than one orientation | Assembly allowance and any hole correction |
| Orientation | Print comparable features along different axes | Tradeoffs in surface finish, dimensional accuracy and strength |
Fit coupon for the plotter
The plotter package includes a bearing-fit coupon STL for checking the printed fit before making a complete motion assembly. The build interface lists its dimensions and provides the matching parts.
This is an available digital test piece. Its CAD dimensions do not establish the printer's actual tolerance. We will measure the printed coupon and compare insertion and retention with the real hardware before accepting a fit.
Turning tests into design rules
We will photograph the labelled pieces and record both failures and successful features. A useful conclusion is specific: the feature, orientation, settings and observed limitation. A clean-looking test print alone does not establish a numerical clearance or bridge limit.
The group characterization concerns printing. Each student's scan capture, processing and scan result belong in the individual assignment; they should not replace the shared printer tests.