01Getting started
Every print follows the same four-step loop. Learn the loop and everything else is just detail:
- Find a model — design one, or download an
.stlfile from a model library. - Slice it — software turns the 3D shape into layer-by-layer instructions (
.gcode). - Print it — the machine heats up and draws those layers in melted plastic.
- Remove & clean up — pop it off the bed, trim any stray strings.
Level the bed first — always
If you only remember one thing, remember this. The gap between the nozzle and the print bed has to be just right: too far and the plastic won't stick, too close and it gets squished or clogs. The classic test is the paper trick — slide a normal sheet of paper under the nozzle and adjust until you feel a light drag, like the paper is being lightly pinched.
Roughly 8 out of 10 first-print failures come down to bed leveling or first-layer height. Before you blame the printer, the filament, or the model — re-level.
What you actually need
- A printer (any entry-level FDM machine is fine to learn on)
- A spool of PLA filament — the easiest plastic to start with
- A slicer program installed on a computer
- A scraper or spatula, and a pair of flush cutters for cleanup
02Slicing basics
A slicer is the bridge between a 3D model and your printer. It takes the shape and decides the path the nozzle travels on every single layer. You mostly tweak a handful of settings:
| Setting | What it does | Safe starting point |
|---|---|---|
| Layer height | Thickness of each layer. Smaller = smoother but slower. | 0.20 mm |
| Infill | How solid the inside is. Most prints don't need to be solid. | 15–20% |
| Print speed | How fast the nozzle moves. Slower is more reliable. | 50 mm/s |
| Supports | Removable scaffolding for steep overhangs. | On if needed |
| Brim | A flat skirt that boosts bed adhesion. | On for tall/small parts |
The 45-degree rule
Plastic can't print on thin air. A printer can usually handle overhangs up to about 45° from vertical on its own. Steeper than that and you'll want supports — or better, rotate the model so the tricky part faces up. Thinking about orientation before you slice saves a lot of grief.
Most slicers ship with tested profiles like "0.2 mm Standard". Start there. Change one setting at a time so you actually learn what each one does.
03Filament types
Filament is just plastic string on a spool, sold in 1.75 mm thickness for most printers. Each kind melts at a different temperature and has its own personality. Here's the cheat sheet:
| Type | Best for | Nozzle | Difficulty |
|---|---|---|---|
| PLA | Almost everything — toys, models, learning | 190–220 °C | Easy |
| PETG | Sturdy parts, water bottles, outdoor use | 230–250 °C | Medium |
| ABS | Heat-resistant, tough mechanical parts | 230–250 °C | Hard |
| TPU | Flexible, rubbery things — phone cases, straps | 210–230 °C | Medium |
Just starting? Use PLA.
PLA is made from plant starch, prints cool, barely smells, and doesn't warp much. It's the friendliest plastic there is. The trade-off is that it goes soft in heat — leave a PLA print in a hot car and it'll sag. For anything that needs to survive sun or stress, step up to PETG once you're comfortable.
Filament soaks up moisture from the air, and wet filament prints badly — popping, rough surfaces, weak parts. Keep spools in a sealed box with a silica gel pack between sessions.
04Troubleshooting
When a print misbehaves, it's almost always one of these. Match the symptom, try the fix, change one thing at a time:
| Symptom | Likely cause | Fix |
|---|---|---|
| Print won't stick | Nozzle too high, dirty bed, no brim | Re-level, clean bed with soap/IPA, add a brim |
| Spaghetti / bird's nest | Print came loose mid-job | Improve adhesion, slow first layers, check supports |
| Stringing (fine hairs) | Too hot, or under-retraction | Lower nozzle 5–10 °C, enable/increase retraction |
| Warping (corners lift) | Cooling too fast, low bed temp | Heat the bed, add a brim, block drafts |
| Layers splitting | Nozzle too cool, fan too strong | Raise temp 5–10 °C, reduce part cooling fan |
| Clogged nozzle | Wrong temp, dust, or wet filament | Heat & do a "cold pull", dry the filament |
| Rough top surface | Not enough top layers / over-extrusion | Add top layers, fine-tune flow rate |
Treat a failed print like a clue, not a defeat. Look at where it failed — the first layer, a specific height, an overhang — and that tells you which setting to chase. Stuck on a term? The glossary has plain-language definitions.