In short
- Extra walls make a print stronger than denser infill and usually cost less.
- A bracket with 4 walls and 20% infill costs PLN 15.97, and with 2 walls and 40% PLN 16.76.
- A print is weakest where the layers meet, so its orientation on the bed matters.
- Sometimes it's better to change the material: PETG handles impacts better, and PA6-CF heavy loads.
Many people assume the strongest print is one with 100% infill. In practice, strength depends mostly on the walls, how the model lies on the bed and the material. Below are four common beliefs and how things really are.
“More infill means a stronger part”
When a part bends or twists, the outer walls do most of the work. The inside carries far less, so adding infill quickly stops paying off. Switch walls and infill to see the weight, time and price:
- Weight
- 19 g
- Print time
- 37 min
- Price
- PLN 14.44
our standard for PLA
A cross-section of the bracket: walls (perimeters) on the outside, infill inside. Weight, time and price worked out with our price list.
A bracket with 4 walls and 20% infill costs PLN 15.97, and with 2 walls and 40% infill PLN 16.76. With solid infill the price goes up to PLN 23.72, and the part is heavier and takes longer to print.
“The infill pattern doesn't matter”
It does, though less than walls and infill density. Each pattern spreads forces differently inside the print:
For flexible TPU, gyroid works best because it bends the same way in every direction.
“Only the shape matters”
The same model placed differently on the bed can be noticeably weaker. Layers hold on to each other less well than the material itself:
Same shape, same material. A print is weakest where layers meet, so we orient the model so the load doesn't pull the layers apart.
- Orient the part so the load runs along the layers rather than pulling them apart.
- Print hooks, hangers and brackets on their side, not standing up.
- A higher printing temperature and less cooling bond the layers better.
“PLA is too weak”
PLA is stiff and fairly strong. It does crack on impact and soften in the heat, though. Instead of adding walls, it's often enough to change the material: PETG handles impacts better, and PA6-CF replaces aluminium in light-duty uses.
Settings for typical parts
| Part | Walls | Infill | Orientation |
|---|---|---|---|
| Figurine, decoration | 2 | 10–15% | any |
| Enclosure, organiser | 2–3 | 20% | base on the bed |
| Holder, hanger | 4 | 20–40% | on its side |
| Gear | 4–6 | 40% | flat |
| TPU gasket | 2 | 100% | flat |
If the part has to carry a heavy load, write to us before ordering. We'll help you choose the material and settings.