¶ Definition
Brittle prints break or snap easily with little bending. They feel stiff but fragile — not suitable for functional use or long-term durability.
¶ Signs
- Breaks or cracks easily when bent
- Snaps during normal use or assembly
- Small parts chip or flake when touched
¶ Root Causes
¶ Printing Settings
- Under-Extrusion – Printer fails to push enough filament through the nozzle
This leads to weak internal structure and layer separation. Causes include a clogged nozzle, low temperature, or an uncalibrated extruder. - Excessive Cooling – Fan cools the filament too quickly before layers bond
This reduces adhesion between layers, especially with PLA and small parts. - High Print Speed – Printing too fast prevents proper layer fusion
Filament doesn't have enough time to melt and stick, making prints more fragile. - Low Nozzle Temperature – Filament doesn’t melt fully during printing
This causes poor flow and weak bonds between layers. Always use the recommended temperature range for each material.
¶ Filament Characteristics
- Moisture Absorption – Filament absorbs water from air, forming steam bubbles during extrusion
This weakens the layer bonding and creates internal stress, especially with nylon, PETG, ABS, TPU, and ASA. PLA is less sensitive but can still degrade if stored poorly.
¶ Model Design
- Sharp Corners – Stress concentrates at hard angles, causing cracks
Designs with tight angles or thin features are more likely to snap under pressure. - Thin Walls or Sparse Infill – Structure lacks internal support
This reduces strength and makes the part more likely to break, especially under impact or load.
¶ Step-by-Step Solutions
¶ 1️⃣ Dry Your Filament
Wet filament = weak prints.
Use a filament dryer or a low-temp oven before printing.
| Filament Type | Temp (℃) | Temp (℉) | Duration |
| PLA series | 50 | 122 | 7 hours |
| PETG series | 65 | 149 | 7 hours |
| TPU series | 70 | 158 | 7 hours |
| ABS/ASA | 75 | 167 | 7 hours |
| PC Professional | 75 | 167 | 7 hours |
| Easy Nylon | 95 | 203 | 7 hours |
¶ 2️⃣ Raise Nozzle Temperature
Increase nozzle temp by 5–10 °C within the safe range to improve layer bonding.
¶ 3️⃣ Slow Down Print Speed
Try printing at 40–50 mm/s to allow better layer fusion.
¶ 4️⃣ Reduce Cooling Fan Speed
Set fan to 40–60% instead of 100%.
Too much cooling makes layers separate more easily.
¶ 5️⃣ Fix Under-Extrusion
Clean the nozzle
Check extruder tension
Recalibrate flow rate
¶ 6️⃣ Anneal the Printed Part (optional)
Heat-treat parts to improve strength.
⚠️ Slight shrinking or warping may happen — test on a spare print first.
¶ Still Not Solved?
If the issue persists, please contact us anytime at service@overture3d.com.