The Choosy Express V2
Overview
Dive into the world of innovative firearm modifications with The Choosy Express V2, a cutting-edge 3D printable design for AR enthusiasts. This downloadable file offers a unique DIY select-fire solution that pushes the boundaries of customization for your AR setup.
Crafted by jimothy.perkins, this design is a modified version of the Yankee Boogle, engineered to provide select-fire functionality without altering the receiver or fire control group (FCG). It’s tailored to work seamlessly with most AR configurations, including Geissele Triggers and some high-shelf lowers, making it a versatile addition to your collection. Whether you're a seasoned builder or a passionate hobbyist, The Choosy Express V2 brings a new level of personalization to your firearm projects.
The Choosy Express V2 Features
The Choosy Express V2 stands out with its innovative select-fire mechanism, designed to actuate the trigger disconnector bar as the bolt carrier group (BCG) goes into battery, releasing the hammer akin to the original Yankee Boogle. What sets it apart is a secondary spring design that ensures the sear remains clear of the disconnector by default, enhancing reliability.
Key highlights include:
- Compatibility: Works with most AR setups, including Geissele Triggers and specific high-shelf lowers.
- Special Requirements: Requires an M16 cut BCG and a specific geometry on the inside wall of the lower for proper function.
- Non-Compatible: Not designed for use with M16 FCGs, ensuring focused functionality.
This design prioritizes ease of integration while maintaining the integrity of your existing setup, making it a must-have for DIY firearm enthusiasts looking to explore select-fire capabilities.
Difficulty & Build Time
- Skill Level: Intermediate
- Estimated Build Time: 8-12 hours
- Required Experience: Familiarity with AR platforms, trigger mechanisms, and 3D printing basics
Hardware and Tools Required
Required Hardware
- M16 cut Bolt Carrier Group (BCG)
- AR lower with specific internal geometry on the right inside wall
- Compatible trigger setup (e.g., Geissele Triggers)
Recommended Tools
- 3D printer with suitable filament compatibility
- Basic hand tools for assembly (screwdrivers, wrenches)
- Calipers for precise measurements during installation
- Cleaning supplies for post-print finishing
The Choosy Express V2 Parts
The Choosy Express V2 file package includes detailed STL files for printing the components necessary for the select-fire modification. These files are designed for precision, ensuring that the sear and spring mechanisms function as intended within your AR setup. For optimal results, we recommend printing with high-strength materials like PETG or ABS to withstand the mechanical stresses of firearm operation.
Pay attention to layer adhesion and infill density during printing to ensure durability. Detailed build instructions are available as a PDF guide at this link, providing step-by-step guidance for assembly and installation.
Printer Compatibility & Settings
The Choosy Express V2 STL files are compatible with most consumer-grade FDM 3D printers, such as Ender 3, Prusa i3, or similar models capable of handling detailed prints. For materials, we recommend using PETG or ABS due to their strength and heat resistance, which are crucial for firearm components. PLA is not advised as it may not withstand the operational stresses.
Suggested print settings include a 0.2mm layer height for detail, 50-75% infill for structural integrity, and a nozzle temperature suited to your chosen material (typically 230-250°C for PETG, 240-260°C for ABS). Ensure proper bed adhesion and consider using supports for overhangs to maintain the precision of critical components like the sear.
Conclusion
The Choosy Express V2 is an exciting opportunity for AR enthusiasts to explore select-fire functionality with a DIY approach, offering compatibility with a range of setups and innovative design features. Remember to follow all applicable laws and ensure you are properly certified or licensed before producing this design, as outlined in the disclaimer. For further support, join the community at thegatalog.com to connect with fellow builders and access additional resources.
