From STL to a printed part

An STL file describes the shape of a part. A 3D printer cannot read it directly, so a slicer program first turns it into layers.

Safety: the nozzle and bed get hot enough to burn. Children must print only with an adult beside them. Keep the room aired, and never reach in while the printer moves.

The steps

1. Download the STL from the project page.
2. Open it in a free slicer program.
3. Lay the flattest face on the bed.
4. Choose the material and the settings below.
5. Slice it and check the preview, layer by layer.
6. Send the file to the printer and watch the first layer.

Good starting settings

• Layer height: 0.2 mm.
• Infill: 20% for most parts, and 30% or more for parts that carry a load.
• Walls: 3.
• Supports: only where the part overhangs by more than about 45°.

Each project lists its own settings beside the file. Follow those when they differ.

Which material?

• PLA is the easiest to print, but it softens in heat. Avoid it in a car or in sunlight.
• PETG is tougher and handles more heat. Most of our robot parts use it.

When a print fails

• The part lifts off the bed: clean the bed, and set the first layer closer.
• Stringy threads: dry the filament, or lower the temperature a little.
• A part will not fit: printers differ, so sand it or print a small test first.

Print one small test piece before a long job. It can save hours of time and a lot of filament.