First layer: the foundation of the whole 3D print

Why it is so important

Everything that is printed stands on the first layer. It has to stick well to the bed and hold for the whole print, otherwise the part comes loose or deforms (see adhesion, warping). The printer therefore lays it more slowly and slightly pressed into the bed, often at a higher temperature.

During calibration, the height of the nozzle above the bed is set to tenths of a millimetre, as the Prusa guide also describes. Too high means weak adhesion, too low means squashed plastic.

Elephant foot

A pressed-down first layer spreads a little to the sides, and the bottom edge of the part forms a small bulge called elephant foot, see also the Prusa guide. It matters with parts that fit together, where a millimetre counts. Allow for it when designing tolerances (tolerances).

How design deals with it

• Put the largest surface on the bed. The greater the contact, the better the part holds.
• Keep the underside flat. A rounded or pointed bottom has too little contact and needs supports or a brim.
• Allow for the bottom edge to be a tenth of a millimetre wider.
• Design a small chamfer on the bottom edge, which eases the elephant foot.

With us

Before printing, the model really is prepared on our server. If the bottom surface is not big enough or the part stands only on a tip, supports (generated automatically and included in the price) or a brim may be needed. If you see that your part stands on an edge, write to us. We photograph every batch before it ships.

Why a first layer fails

• A dirty bed. Fingerprints and grease make adhesion worse, and the bed is cleaned with isopropyl alcohol.
• Wrong nozzle height. Too high or too low gives weak or uneven lines.
• A cold bed or nozzle. The plastic does not bond and comes off.
• Little contact. The model is too sharp and does not hold.