New 3D Printer Owner's Guide: Finding Models, Slicing, and Your First Prints

Getting a first 3D printer is a bit like getting a first car with a manual transmission — the machine is capable, but there's a real skill stack between "it's plugged in" and "it makes the thing I imagined." This guide walks the whole pipeline in order: finding a model, preparing it, slicing it, and printing it, with the pitfalls flagged at each stage.

The Pipeline, At a Glance

Find a model — a 3D file (usually .STL or .3MF) someone else made, or one you design yourself.
Slice it — convert that 3D shape into G-code, a list of instructions telling the printer exactly where to move and when to extrude.
Print it — send the G-code to the printer and manage the physical process.

Each stage has its own failure modes, and almost every "my print failed" problem traces back to a decision made in stage 1 or 2, not a broken printer.

Stage 1: Finding Models

You don't need to know CAD to start. The vast majority of beginner projects come from existing free model repositories:

Printables (by Prusa) and Thingiverse — the two biggest general repositories, huge selection, filterable by category.
MakerWorld (by Bambu Lab) — newer, well-organized, often includes pre-made slicer profiles.
Thangs — good search, including geometric similarity search (upload a picture, find similar models).

See Best Sites for Free 3D Models for a fuller rundown including niche/specialty sites. For your first few prints, look specifically for models tagged "beginner friendly," "no supports needed," or "print in place" — these are curated to avoid the failure modes covered in Stage 2.

What to download: Grab the .STL (or .3MF if offered — it can include color/plate info) rather than any proprietary CAD source file unless you actually plan to edit it. Read the model's print notes/comments section before slicing — other people's failed and successful prints are usually documented there, including what settings worked.

If you eventually want to design your own parts instead of downloading them, that's a separate skill (CAD) worth tackling once printing itself feels routine — don't try to learn both at once. When you're ready, see the free tools below.

Free 3D Modeling Tools (When You're Ready to Design Your Own)

Downloading models covers a lot of ground, but eventually you'll want something custom — a bracket that fits your exact space, a replacement part for something broken, a name plate. You don't need expensive software for this; the free tools below cover nearly every style of design work a maker needs.

Tinkercad — free, browser-based, block-and-shape modeling. The easiest possible starting point: drag primitive shapes, combine and subtract them, no installation required. Great for simple functional parts (boxes, brackets, mounts) but limited for organic or highly precise mechanical shapes.
FreeCAD — free, open-source, parametric CAD (like the free-software equivalent of SolidWorks or Fusion 360). Parametric means you define dimensions and relationships, then edit them later without rebuilding the model — the right choice once you're designing anything mechanical, threaded, or dimensionally precise. See How to Use FreeCAD for Makers.
OpenSCAD — free, code-based modeling: you describe the shape in a script rather than dragging it with a mouse. Unintuitive at first if you've never coded, but extremely powerful for parametric, repeatable designs (change one number, regenerate the whole part). See How to Use OpenSCAD for Parametric Maker Projects.
Fusion 360 — free for personal/hobbyist use (with some limitations), industry-standard parametric CAD. More capable than FreeCAD in places, but cloud-account-based and the free tier's terms have shifted over the years, so check current eligibility before committing significant projects to it.
Blender — free, open-source, built for organic/artistic modeling (sculpting, characters, terrain) rather than precise mechanical parts. The right tool if you're printing miniatures, sculptures, or anything with curves and detail rather than flat mating surfaces.

Which to pick: mechanical/functional part with exact dimensions → FreeCAD or Fusion 360. Quick simple shape, no learning curve tolerance → Tinkercad. Parametric/repeatable part you'll tweak often → OpenSCAD. Organic/artistic model → Blender.

Whatever you design, it still needs to follow the same physical rules as a downloaded model — overhangs, tolerances, wall thickness. Designing Parts for 3D Printing: Tolerances, Overhangs, Supports, and Design Rules covers exactly that, and is worth reading before your first custom design rather than after a failed print.

Stage 2: Slicing — Turning the Model into Instructions

The slicer is the software bridge between the 3D model and your specific printer. It "slices" the model into horizontal layers and generates the toolpath (G-code) for each one. This is where most print quality is actually decided — more so than the printer hardware itself.

Which slicer to use

If you have an Anycubic printer (like the Kobra 3), use Anycubic Slicer Next — see the complete settings guide.
OrcaSlicer is a strong general-purpose free option that works well across brands — see the OrcaSlicer Complete Guide.

The settings that actually matter for a beginner

Layer height — 0.2mm is the standard "just print it" default. Lower (0.12mm) looks better but takes longer; higher (0.28mm+) is faster but rougher. Don't touch this until you understand why you'd want to. Full detail: 3D Print Layer Height Guide.
Orientation on the bed — how the model sits matters enormously. Flat surfaces down, tall thin things vertical when possible, and anything with overhangs rotated to minimize them. Bad orientation is the #1 cause of needing supports at all.
Supports — scaffolding the slicer adds under overhangs so plastic isn't extruded into thin air. Needed for steep overhangs (roughly beyond 45° from vertical) and bridges longer than a few centimeters. They add print time and require removal afterward, and can mar the surface they touch, so the real skill is orienting the model to avoid needing them in the first place. See 3D Print Supports: When You Need Them and How to Minimize Waste.
Infill — the internal lattice fill, usually 15-20% for a first print. Higher infill = stronger and heavier but much slower; most decorative prints don't need more than 10-15%.
Print speed/temperature — use the slicer's built-in filament profile for whatever filament you bought rather than guessing. Every reputable slicer ships with presets for PLA/PETG/ABS/TPU that are a safe starting point.

Not sure what settings to start with for a specific filament brand? The Material Settings Lookup tool pulls dialed-in starting points from the materials library instead of guessing.

Once sliced, the software estimates print time and material use, then exports G-code to an SD card, USB stick, or sends it over the network depending on your printer.

Stage 3: Printing

Before every print

Bed leveling / first-layer calibration — the single most important physical step. If the nozzle is too far from the bed, the first layer won't stick; too close, and it'll scrape or clog. Most modern printers (including the Kobra 3) have auto-leveling, but it's still worth watching the first layer go down.
Bed adhesion — a clean bed (isopropyl alcohol wipe) is often all you need for PLA. If parts are warping or lifting at the corners, a brim (a thin single-layer skirt added around the base in the slicer) usually solves it.
Filament loaded and dry — PLA is the forgiving, beginner-friendly material to start with. Keep spools in a sealed container with desiccant when not in use; damp filament causes stringing and popping sounds during extrusion.

During the print

Watch at least the first 5-10 minutes in person. This catches the two most common catastrophic failures early: a first layer that isn't sticking (peel it off, re-level, try again) or the nozzle catching/dragging a piece that's warping upward (pause and remove before it turns into a tangled mess, sometimes called "spaghetti").

If something goes wrong

Stringing, warping, layer shifts, and elephant's foot are all common, all fixable, and none of them mean the printer is broken. The 3D Printing Troubleshooting Guide covers 30+ specific problems with fixes, and is worth bookmarking rather than memorizing up front.

After the Print

Removing supports, sanding, and (optionally) painting or smoothing the finished part is its own set of small skills — see 3D Print Finishing and Smoothing when you get there. It's normal for your first handful of prints to need some cleanup; that's part of the process, not a sign you did something wrong.

If You Have a Kobra 3 Specifically

Start with the Anycubic Kobra 3 Complete Setup Guide for unboxing, calibration, and your literal first print, then the slicer settings guide once you're ready to move past the default profiles — especially useful if you're using the ACE Pro for multi-color prints.

A Sane First-Week Plan

Print something small, flat, and support-free from a "beginner friendly" tag first — not your dream project. A calibration cube or a simple keychain, not a complex miniature.
Use the slicer's default filament profile. Don't tune settings yet.
Watch the first layer in person every time until you trust the printer.
Once 2-3 prints succeed cleanly, start experimenting with orientation, supports, and infill on slightly more ambitious models.
Only then start adjusting temperature/speed/layer height manually — and change one variable at a time so you know what actually helped.

Related Guides

Loading_