Automatic Filament Rotator (2 x 360 degr/hour)

Description

Filament Turner Controller - Build Guide

Got inspired by this post made another version using a very cheap controller board and stepper motor setup.

⚡ Features

Automatic rotation every 5 minutes
Complete 360° rotation in approximately 30 minutes
USB powered - works with any 5V USB charger
Easy installation - no soldering required (optional breadboard method, recommended to solder 6 wiresfor a clean setup)
Open source firmware - customizable and upgradeable

Component	Quantity	Notes	Estimated Cost
Wemos D1 Mini (ESP8266)	1	Clone is fine (~$1-3 on AliExpress)	$10
28BYJ-48 Stepper Motor	1	5V version with gearbox	$3
ULN2003AN Driver Board	1	Usually comes with motor kit	$2
USB Micro-B Cable	1	Any 5V USB charger or power bank	$3
Dupont Jumper Wires	8+	Male-to-female (20cm)	$2

Total: ~$12 (less if you have spare cables)

Wemos D1 Mini - Small WiFi development board
28BYJ-48 Motor - Geared stepper motor with 4 coil wires (typically colored brown, orange, pink, yellow)
ULN2003AN Board - Darlington driver with 4 signal inputs (IN1-IN4) and motor connection terminals

Connect the following Wemos D1 pins to the ULN2003AN driver board (I suggest to soldering it in your final build.):

Problem	Solution
Motor doesn't turn	• Check USB power supply (5V, ≥1A) • Verify pin connections • Check motor coil wires are seated
Upload fails	• Try different USB cable • Hold GPIO0 to GND while plugging in USB • Verify correct COM port selected
Rotation is jerky	• Increase DELAY_BETWEEN_STEPS (e.g., to 3-5ms) • Check power supply voltage under load
Motor runs in wrong direction	• Swap any two motor coil wires on the ULN2003AN board
Partial rotation	• Increase DELAY_BETWEEN_STEPS • Check USB power supply amperage