3D printing
Design printed robot parts around load direction, walls, fasteners, fit, material, and a reproducible print record.
Fused filament fabrication, also called FDM, builds a part by depositing melted thermoplastic in layers. It is useful for custom geometry, but a printed part's behavior depends on both its design and the process that made it.
First printed part
Start with a cable-retention bracket, mount, drilling fixture, or object guide that solves a fit or routing problem. Avoid making a safety-critical lifting part the team's first untested print.
Print orientation
Printed parts are anisotropic: their properties vary with direction. Layer interfaces can fail differently from material deposited along a layer. Orient a loaded bracket so its likely bending and tension do not simply peel layers apart, then validate the real part.
Also consider support removal, surface quality, hole accuracy, and bed contact. A flat cosmetic face is not necessarily the best orientation for a loaded pivot.
Walls and infill
Walls, ribs, fillets, and local reinforcement can carry loads more effectively than increasing infill everywhere. Keep enough material around seats, holes, and the base of a . Avoid abrupt section changes that concentrate stress.
Wall geometry should be compatible with the chosen extrusion width and behavior. Inspect the sliced preview: a thin wall that appears in may be omitted or formed differently during slicing. There is no universal wall count that validates every structural part.
For fasteners, use washers, suitable inserts, or through-bolts and nuts where repeated is required. A compression sleeve can prevent a bolt crushing plastic. Follow insert installation guidance and test pullout or joint behavior in the actual load direction.
Filament selection
| Material family | Possible use | Important check |
|---|---|---|
| PLA | Fast and some lightly loaded rigid parts | Heat exposure and impact behavior |
| PETG | Functional guides, covers, and brackets | Print quality, , and dimensional fit |
| TPU | Compliant fingers, bumpers, and rollers | Hardness, deformation, and print consistency |
| Nylon or reinforced engineering filament | Parts needing its specific measured properties | Moisture control, printer compatibility, abrasion, and fit |
Use the supplier’s datasheet and printer profile for the exact filament. A “carbon-filled” label alone does not tell you how strong the printed part or its layer bonds will be.
Print testing
Use a fit coupon for uncertain holes and interfaces. Inspect for under-extrusion, warping, cracks, and incomplete layers. Install the part without forcing alignment, then test the intended load and repeated motion in a controlled setup.
Record material, printer, nozzle, orientation, layer height, extrusion width, walls, infill, support settings, and revision. Keep the sliced file or profile needed to reproduce it. A replacement printed with a different orientation is a different mechanical part even if the is unchanged.
Print spares before an event and check that they fit. Compare weight, print time, , and where parts fail when deciding whether a material or design change helped.