Support Structures in 3D Printing: What They Are and When You Need Them

What Are Support Structures?

Support structures are temporary scaffolding printed beneath overhanging sections of your model. Because FDM 3D printers deposit material layer by layer, they cannot print in mid-air — any part of the model that extends beyond 45° from vertical needs support material beneath it.

The 45-Degree Rule

As a general rule: if any surface of your model angles more than 45° away from vertical, that section needs supports. Below 45°, the printer can usually bridge the gap itself. Above 45°, the layers will sag and ruin the print.

Types of Supports

• Normal supports: Standard grid or tree-like scaffolding. Most commonly used.
• Tree supports: Branch-like structures that touch the model at minimal points, making removal easier.
• Interface layers: Smoother material layer between support and model for easier removal.

Design Tips to Minimize Supports

1. Orient your model smartly: Rotating the model 90° can eliminate most overhangs.
2. Use chamfers instead of fillets: 45° chamfered edges don't need supports, while round fillets do.
3. Add bridges deliberately: Flat horizontal spans under 60mm can usually bridge without supports.
4. Split complex models: Divide the model into parts that each print without supports, then glue them.

Removing Supports

After printing, supports are removed manually with pliers and cutters. Tree supports are typically easier to remove than normal supports. The contact area will require sanding for a clean finish.

Ask Jordan3DPrint

Not sure if your design needs supports? Send us your STL file on WhatsApp and our team will advise on the best orientation and support strategy.