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Blackdraft Phoenix 2026 + Begadi PRO NEPTUN · Alignment Kit V2.1 · M4 AEG HPA

23,00 €
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Version 2.1 of the hop-up alignment system, designed for M4 AEG HPA replicas with a V2 gearbox.

This kit combines the Blackdraft Phoenix 2026 engine with the Begadi PRO NEPTUN hop-up chamber, ensuring stable alignment between the nozzle and the hop-up chamber. The result is more consistent feeding, a more rigid assembly, and more reliable adjustment for high-performance HPA builds.

The Begadi PRO NEPTUN chamber allows adjustment of the feeding position and supports different nozzle lengths, while the alignment kit keeps the assembly centered within the V2 gearbox. This helps reduce play between the engine, hop-up chamber, and inner barrel.

Compatibility

Component Compatibility
HPA Engine Blackdraft Phoenix 2026
Hop-up Chamber Begadi PRO NEPTUN
Base Replica M4 AEG
Gearbox V2
Platform M4 / AR15 AEG HPA

What's Included

  • Rear clip for mounting using the rear pin or fixed stock attachment.
  • Base with mounting points for M3 inserts.
  • Side clip for routing and organizing the HPA line.
  • Upper front locking cap for the Begadi PRO NEPTUN chamber.
  • Rear plate with a mounting point for an M5 screw.
  • Support pieces to keep the hop-up chamber and nozzle properly aligned.

Installation and Adjustment

  1. Part Preparation

    • Print the parts with 65–80% infill.
    • Lightly sand the internal and contact surfaces until a clean fit is achieved.
    • If necessary, apply dry lubricant or wax to contact surfaces to facilitate assembly and maintenance.

  2. Assembly

    • Insert the base into the lower receiver or compatible V2 gearbox structure.
    • Install the M3 inserts in their designated slots.
    • Install the Blackdraft Phoenix 2026 engine and route the HPA line through the side clip.
    • Fit the Begadi PRO NEPTUN chamber alongside the inner barrel.
    • Install the upper cap to lock the chamber in its operating position.

  3. Final Alignment

    • Install the rear clip using the replica's rear pin or stock mounting point.
    • Secure the rear plate with an M5 screw and washer to increase rigidity.
    • Check that the nozzle enters the chamber centrally without lateral rubbing.
    • Perform dry feeding tests before adjusting pressure, dwell, and hop-up.

Important: Adjust the nozzle length and feeding position according to your specific setup. Proper alignment should ensure consistent feeding without marking BBs, causing double feeds, or applying excessive pressure to the bucking lips.

Required Components (Not Included)

  • 4× M3 × 4.2 mm inserts
  • 4× M3 × 8 SHCS screws
  • 1× M5 screw
  • 1× M5 washer

Recommended Lower Receivers

A metal ICS lower receiver is recommended for maximum rigidity in demanding HPA builds.

If you prefer to 3D-print your own lower receiver, the following Gearbox V2 Universal Lower models are compatible:

  • Version 3
  • Version 4.2
  • Version 4.3 MTW

You can find them HERE.

3D Printing Parameters

  • Approximate printing time: ~1 h 30 min
  • Recommended material: PLA+
  • Layer height: 0.10 mm – 0.15 mm
  • Recommended infill: 65–80%
  • Supports: Not required unless necessary for your chosen print orientation.

Manuals

Installation and adjustment manuals are available in the Manuals section of the website or on the project's Discord server.