Version 2.1 of the hop-up alignment system, designed for M4 AEG HPA replicas with ICS split configuration and compatible with the ICS lower.
This kit is designed for the PolarStar F2 engine and MAXX Model chamber, providing precise alignment between the nozzle and the chamber to improve feeding consistency and overall system stability.
Compatibility
| Component | Compatibility |
|---|---|
| HPA Engine | PolarStar F2 |
| Hop-up Chamber | MAXX Model |
| Base Platform | M4 AEG / ICS MPX (BlowBack) |
| Gearbox | V2 / ICS SPLIT |
What’s included
- Rear clip for mounting via rear body pin or fixed stock.
- Base with housing for M3 inserts (brass optional).
- Side clip for routing the F2 HPA line.
- Top locking cap specifically designed for MAXX Model chamber.
- Rear plate with mounting point for M5 screw (extra reinforcement).
Installation and setup
-
Printing and preparation
- Print parts with 65–80% infill.
- Lightly sand internal and contact areas for a clean fit.
- To ease maintenance, apply dry lubricant or wax on sliding surfaces.
-
Assembly in the replica
- Insert the base into the lower and install the M3 inserts.
- Position the rear clip aligned with the rear body pin or stock mounting point.
- Install the MAXX Model chamber with the inner barrel; the top cap locks the assembly and ensures proper centering.
- Route the HPA line from the PolarStar F2 through the side clip to avoid friction or sharp bends.
-
Final fixation
- Secure the rear plate with an M5 screw and washer for maximum rigidity.
- Check that the F2 nozzle enters the MAXX chamber centered, with no lateral play.
- Perform feeding tests and adjust the hop-up accordingly.
Required components (not included)
- 4× M3 inserts × 4.2 mm
- 4× M3 × 8 SHCS screws
Lower recommendations
For maximum rigidity, using a metal ICS lower is recommended.
If you prefer a printed lower, 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
- Estimated print time: ~1 h 30 min
- Recommended material: PLA+
- Layer height: 0.10 mm – 0.15 mm
Manuals
Installation and setup manuals are available in the Manuals section of the website or on the project’s Discord server.
Related products and articles
Similar product designs:
- Blackdraft Phoenix MAXX Model alignment kit AEG ICS MPX (v2.1)
- PolarStar F1 + ICS MY-09 alignment kit for ICS MPX (v2.1)
- PolarStar F1 + MAXX MODEL alignment kit for SR25 DMR
Technical articles for this topic:
Frequently asked questions
What material and dimensions apply to PolarStar F2 + MAXX Model · Alignment Kit V2.1 · M4 ICS MPX HPA?
The public product data does not declare a material or finished dimensions for this design. Check the images, downloadable files, and the exact manufacturing or printing setup before producing it.
What is PolarStar F2 + MAXX Model · Alignment Kit V2.1 · M4 ICS MPX HPA compatible with?
The published tags and categories identify this design with m4, polarstar f2, maxx model, hpa, airsoft, alignment kit. Confirm the exact platform, revision, and mounting points before ordering.
How do I install or prepare PolarStar F2 + MAXX Model · Alignment Kit V2.1 · M4 ICS MPX HPA?
Read the installation notes in the product description, inspect the supplied files and images, and test alignment before final fastening. The required tools, fasteners, printing parameters, or post-processing depend on the specific build.
What are the real-world uses for PolarStar F2 + MAXX Model · Alignment Kit V2.1 · M4 ICS MPX HPA?
This design is intended for projects related to m4, polarstar f2, maxx model, hpa, airsoft, alignment kit. It is useful for a compatible repair, conversion, prototype, replacement, or custom build when the published fitment and project requirements match.
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