Lower Universal Gearbox V3

Universal lower for V2 gearbox, designed for AEG replicas converted to HPA or for ICS configurations with pneumatic engines.

This lower follows the ICS type (split two-piece system) and is optimized for 3D printing in PLA+, offering an affordable and functional alternative to the original metal lower.

Key features

• Universal compatibility: works with M4 AEG replicas using V2 gearboxes and ICS split systems
• Direct threading: screws go directly into the printed body, increasing rigidity without the need for metal inserts
• Magnetic connector support: internal slot for a 3-pin connector with 2.54 mm tabs (compatible with Gate Titan 2 and similar)
• OEM select plate: uses the original selector plate from any V2 gearbox

Tested compatibility

This lower has been successfully tested on replicas from the following brands:

• DBoys
• AMOEBA
• ICS
• G&G

Note: You may need to slightly enlarge the trigger hole and safety lever hole, as each manufacturer uses different thicknesses for these parts.

Design revisions

• Rev. 5: Added housing for select plate
• Rev. 4: New internal wiring channel
• Rev. 3: Adjusted magazine well opening
• Rev. 2: Enlarged grip hole
• Rev. 1: Added version without magnetic connector for standard Gate PCB use

Gate Titan 2 FCU compatibility

Only compatible with the version without magnetic pin support.
If your Gate Titan 2 uses a 3-pin magnetic connector with 2.54 mm tabs, this lower supports it — simply slide the connector in from the inside.

• Buy magnetic connector on AliExpress

Required hardware (not included)

• 6× short M3 screws: for general lower assembly
• 3× long M3 screws: one at the rear and two for the grip
• 4–8× M3 nuts: optional, to reinforce grip mounting

Screws thread directly into the printed body, eliminating the need for metal inserts while still providing sufficient rigidity.

ICS-compatible design

This lower follows the ICS standard:

• Central slot for the split system
• Clearance for the upper gearbox tabs
• Compatible with this project’s alignment kit designs

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3D printing parameters

• Estimated print time: ~3–4 h (depending on printer)
• Recommended material: PLA+
• Layer height: 0.15 mm – 0.20 mm
• Recommended infill: 75–100% (for maximum strength)
• Supports: yes, in the grip area and magazine well

Manuals

Installation and setup manuals are available in the Manuals section on the website or on the project’s Discord server.