How 3D Printers Work

3D printing builds objects layer by layer from a digital model. Two technologies dominate home and small-business printing.

FDM (filament)

A heated nozzle melts plastic filament and draws each layer.

• Strengths: affordable, large build volumes, strong functional parts, many materials, low running cost.
• Limits: visible layer lines, fine detail limited by nozzle size (commonly 0.4 mm), overhangs need supports.

Resin (SLA / MSLA)

UV light cures liquid resin layer by layer.

• Strengths: very fine detail and smooth surfaces; ideal for miniatures, jewellery masters, dental and detailed figurines.
• Limits: smaller build volume, messy post-processing (washing and curing), resin is a skin and eye irritant requiring gloves, eye protection and ventilation.

Choosing a first printer

Look for automatic bed levelling, a direct-drive or well-supported extruder, an enclosed or easy-to-enclose design for higher-temperature materials, an active user community and available spare parts. Modern "bed-slinger" and CoreXY printers from reputable brands print well out of the box.

Safety

• Place printers on stable, non-flammable surfaces; do not leave early prints unattended.
• Ventilate: melting plastics and especially resin release fumes and particles.
• Keep resin away from skin and drains; cure waste resin before disposal.

The workflow at a glance

Model (CAD / Blender / download) → export STL/3MF → slicer → G-code → print → post-process

Check yourself

• When is resin a better choice than FDM?
• What protective equipment does resin require?
• What does a slicer produce?