Why do the corners of my 3D prints always lift?

Corners lift because they are the points of highest stress concentration during thermal contraction. As the plastic cools and shrinks, the tension pulls the edges inward and upward. This is exacerbated by poor bed adhesion or cold drafts.

Does increasing bed temperature always help prevent warping?

Not necessarily. While a warmer bed improves adhesion, setting it too high (above the material's glass transition temperature) can make the bottom of the print too soft, leading to a different type of distortion known as 'elephant's foot' or even causing the part to lose its structural integrity.

What is the difference between a brim and a raft?

A brim is a single-layer thick extension of the part's footprint that attaches to the edges. A raft is a multi-layer thick base that the entire part sits on. Rafts are better for parts with very small contact points, while brims are better for general warping prevention.

Can I use a cooling fan with ABS?

Generally, no. ABS is extremely sensitive to temperature changes. Using a cooling fan will cause the layers to contract too quickly, leading to warping and layer delamination. Only use a fan (at very low speeds) for extremely small details or bridges.

How do I clean a PEI sheet for better adhesion?

Clean it with Isopropyl Alcohol (90%+) between every print. If adhesion drops significantly, you can lightly scuff the surface with fine-grit sandpaper (1000-2000 grit) and then wash it with dish soap and water to refresh the surface.

3D Printing How to Prevent Warping: The Ultimate Pro Guide