NightOwl Integrated Dual Spool Filament Switching System Kit by Morton Jonuschat

Bondtech BMG Extruder — Dual Drive, 1.75mm, Bowden & Direct Drive | IDGA Version

The Bondtech BMG is one of the most widely used dual-drive extruders in the 3D printing community — proven across thousands of builds on Voron, Prusa, Creality, and custom machines. The current version ships with the new white plastic main gear and Integrated Drive Gear Assembly (IDGA) for reduced run-out and improved surface quality on prints. SLS nylon housing, hardened steel dual-drive, compatible with both bowden and direct drive configurations. 1.75mm only.

Note: Bowden adapter is not included.

IDGA — What's New in This Version

The Integrated Drive Gear Assembly (IDGA) combines a new white plastic main gear with an updated assembly method that reduces filament run-out at the drive point. Run-out — small variations in filament position as it exits the extruder — shows up as surface inconsistency and banding in prints. The IDGA reduces that variation at the source, resulting in cleaner surface quality without any slicer compensation required.

Dual Drive Technology — Both Sides, Full Control

The BMG grips filament from both sides simultaneously using hardened steel drive gears, doubling the contact surface compared to single-drive designs. This means more push force with less motor torque, better grip on flexible filaments that single-drive extruders struggle to feed consistently, and no filament grinding under normal operating conditions. The dual-drive design is the reason the BMG became the community standard for Voron and other high-performance Klipper builds.

Bowden and Direct Drive — One Extruder, Both Configurations

The BMG ships with a built-in fitting for E3D hotends and mounts directly to NEMA17 stepper motors, supporting both bowden and direct drive setups without modification. For bowden use, a separate bowden adapter is required — not included with this unit. The compact, lightweight housing makes it a viable direct drive option where toolhead mass matters.

SLS Nylon Housing — Precision Over Injection Molding

The housing components are produced using Selective Laser Sintering (SLS) in nylon rather than standard injection molding. SLS produces denser, more dimensionally accurate parts with better mechanical properties than injection-molded alternatives — relevant for an extruder where housing flex and gear alignment directly affect feeding consistency.

Specifications

Who Is This For?

The BMG is the right choice for any build where reliable, consistent filament feeding is the priority — Voron V0, Trident, V2.4, custom CoreXY machines, and any bowden setup where single-drive extruders are causing grinding, slipping, or inconsistent extrusion. It's also a proven upgrade for Ender 3 and Prusa users moving to direct drive. If you've been printing with a stock single-drive extruder and chasing surface quality issues, the BMG is the most direct mechanical fix available.

→ Browse all 3D Printer Extruders or explore our full 3D Printer Upgrades collection.

• Hartk's Bowden Y-Splitter
• Filamentalist Rewinder - 80mm Axle from the Enraged Rabbit Community
• Fysetc ERB 2.0 MCU
• ArmoredTurtle's TurtleNeck syncing toolhead buffer

Besides these parts you'll also want an extruder that has both a toolhead and an entry sensor. Some options for this are:

• Clockwork 2
• WristWatch G2

For more information check out the Git.