HT-FRT milspec mod
Overview
Dive into the world of custom AR-15 builds with the HT-FRT milspec mod, a meticulously crafted modification of Hoffman Tactical's FRT-style trigger designed to seamlessly fit into a milspec lower receiver. This downloadable file offers firearms enthusiasts and 3D printing aficionados a unique opportunity to enhance their build with precision-engineered components.
The purpose of this mod is to adapt the original Hoffman Tactical FRT design for compatibility with standard milspec lowers, ensuring a snug fit and reliable performance. It addresses specific fitment issues through targeted geometry tweaks and structural enhancements. Whether you're upgrading an existing setup or starting a new project, this mod delivers practical solutions for a smoother trigger assembly.
HT-FRT milspec mod Features
The HT-FRT milspec mod stands out with its detailed modifications tailored for optimal functionality in milspec lowers. Each component has been refined to address common fitment challenges while maintaining the integrity of the original Hoffman Tactical design.
- 1_block & 1.1_block Updates: Features like the removal of the angled block on the right side, filled-in left and right sides for specific lowers, and an extended top plate for better upper receiver indexing ensure a precise fit. The widened safety channel and tweaked bottom surface/spring channel geometry enhance durability and performance.
- 2_plate Adjustments: Lowered hammer tail interface by 1mm to prevent BCG binding, paired with a slightly increased trigger pin hole diameter for smoother operation.
- 3_safety Enhancements: Extended BCG interface by 0.3mm and moved contact surface forward by 0.5mm, with a wider safety design for improved contact and reliability.
- 4_pin & 4.1_pin Additions: New mating components for 1_block and 1.1_block with 3_safety, ensuring secure assembly and alignment.
These updates, detailed in version logs from v0.1 to v0.3, reflect a commitment to iterative improvement, making this mod a must-have for AR-15 customization.
Difficulty & Build Time
- Skill Level: Intermediate
- Estimated Build Time: 6-8 hours
- Required Experience: Familiarity with 3D printing, AR-15 assembly, and trigger group installation is recommended for successful integration.
Hardware and Tools Required
Required Hardware
- Standard milspec lower receiver components
- Compatible AR-15 upper receiver
- Trigger pins and safety components compatible with milspec lowers
Recommended Tools
- 3D printer with fine detail capabilities
- Calipers for precise measurement during assembly
- Allen keys or screwdrivers for securing components
- Sandpaper or finishing tools for post-print cleanup
- Drill (if minor adjustments are needed for fitment)
HT-FRT milspec mod Parts
The HT-FRT milspec mod includes multiple STL files corresponding to the modified components like 1_block, 1.1_block, 2_plate, 3_safety, 4_pin, and 4.1_pin, as well as Hoffman Tactical's original files for reference (added in v0.3). For best results, print these parts with a high infill density (50-70%) to ensure structural integrity under stress. PETG or ABS is recommended for durability, given the mechanical nature of trigger components.
Pay attention to print orientation to minimize weak points, especially for parts like the safety and pins that endure repetitive stress. Post-processing may involve light sanding to smooth surfaces and ensure proper fitment with your milspec lower. Build instructions are available as a PDF guide at this link for detailed assembly steps.
Printer Compatibility & Settings
This mod is compatible with most FDM 3D printers capable of fine detail printing, such as Ender 3, Prusa i3, or similar models with a build volume sufficient for small firearm components. Recommended materials include PETG or ABS for their strength and heat resistance, though advanced users may opt for nylon for added toughness. Use a layer height of 0.1-0.2mm for precision, a nozzle temperature of 230-250°C (for PETG), and a bed temperature of 80-90°C.
Ensure proper bed adhesion to prevent warping, and consider using supports for complex geometries like the safety channel. A well-calibrated printer is crucial to achieve the tight tolerances required for functional trigger parts. Always test-fit printed components before final assembly to confirm compatibility with your specific milspec lower.
Conclusion
The HT-FRT milspec mod is an invaluable resource for AR-15 builders seeking a custom trigger solution that fits seamlessly into a milspec lower, thanks to its thoughtful design updates and compatibility focus. With detailed modifications and included build instructions, it empowers users to achieve a professional-grade result with their 3D-printed components. Download this file today, follow the provided guide, and elevate your firearm customization game with precision and reliability.
