Tolerances: Making Parts Fit 🔧
Clearances for parts that fit together
When designing parts that fit together, you need tolerance - extra space for parts to slide together.
Why Tolerances Matter
3D prints are never perfect:
- Filament expands when cooling
- Layers aren't perfectly aligned
- Elephant's foot at base
Tolerance Guidelines for FDM
| Fit Type | Tolerance | Use Case |
|---|
| Loose | 0.4-0.5mm | Easy sliding |
| Normal | 0.2-0.3mm | Snug but removable |
| Press | 0.1mm | Stays put |
How to Apply
For a 10mm peg to fit in a hole:
- Hole = 10mm + 0.3mm = 10.3mm (normal fit)
- Or peg = 10mm - 0.3mm = 9.7mm
Start with
0.3mm tolerance and adjust!