First-Time Setup & Assembly

The Ender 3 (and Ender 3 V2) ships partially disassembled — you'll bolt together the frame, gantry, and base before it can print. Budget 30-60 minutes for a careful first build.

What's in the box

Pre-wired frame sections (base, Z-axis gantry, X-axis carriage)
A bag of bolts, an acrylic wrench/hex key set, and a spare nozzle
A microSD card (V2 models) with sample G-code and slicer software
A glass or textured PEI-coated spring steel bed sheet

Assembly steps

Bolt the gantry to the base. Use the included L-brackets and hex bolts — snug them by hand first, then tighten with the wrench once the frame sits square. A frame that isn't square causes persistent skew in every print.
Attach the X-axis carriage and belt. Route the GT2 belt around both pulleys and clip it into the carriage tensioner. It should be firm but not guitar-string tight.
Connect the wiring. Each connector is a different size/shape so it can only fit one socket — but double-check the stepper motor and endstop connectors are fully seated, not just resting in the socket. A half-seated connector is the single most common cause of a "dead" axis on a brand-new machine.
Mount the display and check cable routing. Keep cables clear of the belt and lead screw so they don't get caught during motion.

Tip: Photograph each wiring step before you continue — if a stepper doesn't move later, you'll have a reference to check against.

First power-on checklist

Confirm your power supply's voltage switch matches your region (115V/230V) before plugging in — this is the single most damage-prone step in setup.
Home all axes (X, Y, Z) from the printer menu and watch that each one moves toward the endstop and stops cleanly, without grinding.
Run a manual bed leveling pass before your first print — see Manual Bed Leveling Guide.
Load filament by releasing the extruder idler lever, feeding filament in by hand until it reaches the hotend, then releasing the lever so the extruder pulls it the rest of the way.

Danger: Never plug in or power on the printer without visually checking the voltage selector switch on the PSU. Selecting the wrong voltage can destroy the power supply and, in rare cases, is a fire risk.

Once assembly and homing check out, print the included sample G-code file from the microSD card as your first calibration print — it's pre-sliced specifically for a stock machine.