Why Does Geometry Affect Price?
FDM 3D printing price is primarily a function of material volume and print time. Both are directly influenced by your design choices. Here are five rules that consistently reduce cost without compromising function.
1. Hollow Out Solid Bodies
A fully solid cube at 100% infill costs ~4–5× more than the same cube hollowed out with 3 mm walls. If your part does not need solid core strength, shell it. In CAD tools, use the "Shell" command and target 2–4 mm wall thickness.
2. Minimise Support Material
Support structures add material cost and print time - and they have to be removed. Design overhangs to be under 45°, use chamfers instead of horizontal holes, and orient holes vertically where possible. This alone can cut print time by 20–40% on complex parts.
3. Use Split-and-Bond for Large Parts
Our maximum build volume is 250 × 250 × 250 mm. Parts larger than this can be split along natural seams, printed separately, and bonded with acetone (for ABS/ASA) or super glue (for PLA/PETG). Splitting also reduces the impact of any warp on the final assembly.
4. Standardise Wall Thickness
Walls thinner than 1.2 mm are fragile and can fail to print on the first attempt. Walls thicker than 3 mm add unnecessary material. Aim for 1.6–2.4 mm as a universal target for structural walls. This hits the sweet spot of strength, material efficiency, and printability.
5. Reduce Part Count by Integrating Features
Every separate part means a separate print job. Where possible, integrate features - a bracket and its mounting flanges should be one part, not three. FDM can produce complex undercuts and internal channels that injection moulding cannot, so take advantage of design freedom.
A well-designed part for 3D printing is not a CAD solid - it is a hollow shell with ribs where needed.