An STL file isn’t automatically 3D printable. Small mistakes can trip up the print process, but they are easily remedied. Here are the most common design mistakes – and what you can do to repair your STL file, so your 3D model prints correctly.
STL Repair Tip #1: Repair Gaps in Meshes
One of the most common errors encountered when 3D printing are STL files that have holes in their meshes – they are not “watertight”. A 3D printer faced with such a file can’t tell an outer surface from an inner surface. Most of the STL repair tools we list can handle these 3D mesh problems easily.
STL Repair Tip #2: Check for Non-Manifold Geometry
Simply put, non-manifold geometries are identical edges directly on top of each other. Typically this conundrum results from extruding but not moving faces and edges. Non-manifold geometry startles 3D printers as much as anyone else who tries to wrap his head around the idea for the first time. Think about the graphic works of M.C. Escher and you’ll get the idea.
STL Repair Tip #3: Get rid of Floating Surfaces
3D scanning can produce unwanted fragments which result from structures or textures that are unsuitable to the process – e.g. hair, very dark or very bright surfaces. Scans can be reworked before printing by hand (e.g. MeshLab), but automatic solutions to repair STL files are also available in most STL repair software tools.
STL Repair Tip #4: Lose the Thin Walls
It is paramount to set a wall thickness that can support the overall structure. Depending on what use you will put your 3D model to, you must choose a thickness that will yield a robust model at an economic consumption of filament or other material.
STL Repair Tip #5: Minimize the file size
Many cloud-based STL printing services impose upload limits on the files you can upload, often ranging from 64 to 100 MB. This problem can be remedied by automatic down scaling (e.g. MakePrintable or Materialise Cloud) in your 3D design software.