HAFC (Hackman Automatic Filament Cutter)

HAFC V2 available here : 

https://makerworld.com/fr/models/2548786

🔪 HAFC – Hackman Automatic Filament Cutter

by Hackman3D

Mount available here:
https://makerworld.com/fr/models/2216044

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🧠 Concept & Purpose

The HAFC (Hackman Automatic Filament Cutter) is a universal, 100% mechanical system compatible with all FDM 3D printers using 1.75 mm filament.

It was designed to solve a common issue:
👉 filament jams on the spool side (tangles, stuck spools, excessive friction).

Instead of forcing the extruder, the HAFC:

1. detects abnormal tension on the filament,
2. triggers a sliding mechanism,
3. cleanly cuts the filament,
4. the printer detects a filament runout and automatically pauses.

➡️ You just reload filament and resume the print.

No electronics, no sensors — 100% passive and reliable.

⚙️ How It Works

• Filament passes through the HAFC via a PTFE tube
• An internal moving part is held in position by magnets
• If the filament is blocked on the spool side, tension from the extruder:
  • moves the sliding part,
  • actuates a standard BambuLab cutter,
  • cleanly cuts the filament
• The printer’s filament runout sensor then takes over

🧲 8×2 mm magnets prevent accidental triggering caused by normal tension variations.

🖨️ 3D Printing

• ✔️ PLA is sufficient (no thermal stress)
• Supports are already included in the 3MF file provided here
• Designed tolerances for smooth operation
• 5 printed parts make up the HAFC

👉 Recommended orientation and standard settings:
(0.2 mm layer height / 3 perimeters / 20–30% infill)

🔩 Required Hardware

Fasteners & Hardware

• 4 × M3×25 socket head screws
• 1 × M3×16 socket head screw
• 4 × M3 nuts
• 1 × Ø2 mm × 25 mm rod (optional)

Mechanism

• 2 × 8×2 mm magnets
• 1 × BambuLab cutter
• ~12 cm PTFE tube

Filament Connectors

• 2 × M6 pneufit (optional)

➡️ Two versions are available:

• Version with pneufit
• Version without pneufit

AliExpress purchase links

⚠️ Make sure to select the correct product on each page:

M6 Pneufit & PTFE tube     4,19€

M3 screws & nuts                  8,99€

BambuLab cutter               1,93€

Magnets 8x2mm                   2,84€

2x25mm rod                       2,12€

➡️ Total: ~€20, enough to build up to 3 units
(2 versions with pneufit + 1 without pneufit)

🛠️ Assembly Guide (Summary)

🛠️ Assembly Guide (Summary)

1. Insert and glue the 8×2 mm magnets into their slots (check polarity)
2. Assemble the moving part with the Ø2 mm rod
3. Clip the BambuLab cutter into its dedicated slot
4. Assemble the body using M3 screws and nuts
5. Install the PTFE tube (direct or via pneufit, depending on version)
6. Check that the mechanism slides freely

➡️ The system should slide easily. If needed, move it by hand a few times to break it in.

Assembly Details (Photos)

All required parts:

First, install the magnets in the cover (pink part) and in the slider. Glue is recommended.

   If you chose the pneufit option, install them now on the body (large part) and on the slider (smaller part).

Install the cutter by clipping it into the lever.

Install the lever (with cutter) onto the slider.

Insert the assembled slider into the body from the top and secure it using the M3×16 mm screw.

If using the Ø2×25 mm rod, insert it through the side slot of the body into the slider.

Finally, slide the body into the cover and secure everything using 4× M3×25 mm screws and 4× M3 nuts.

⸻

🔄 Compatibility

• ✅ All FDM printers
• ✅ 1.75 mm filament
• ✅ PLA / PETG / ABS / TPU (as long as filament runs in PTFE)
• ❌ Not compatible with 2.85 mm filament

⸻

V1 (Current)

✔️ Fully functional
✔️ Tested in real conditions
✔️ Simple and reliable mechanism

🔹 Coming soon: multiple lever arm lengths, as some cutters are longer than others.
The base version is included; 2–3 longer versions are in preparation and may be uploaded based on feedback.

V2 (If the project gains traction – planned around March 2026)

• More compact housing
• Addition of a return spring for automatic reset
• Design optimization

Thanks to the feedback received across the different platforms, V2 is almost ready. It’s more compact, includes a return spring, and features a new design. I’m planning to release it in late February or early March, but if the project reaches 50 boosts, I’ll release it immediately.

Thank you all!

V3 (Final goal – planned around August 2026)

• Ultra-compact version
• Fully optimized design
• Universal mounting system for all printer brands
  (Prusa, Elegoo, Wanhao, BambuLab, Creality, Anycubic…)
  👉 With your help, as I don’t own all these printers
• Final, definitive version

💬 Downloads, feedback, and likes will decide the future of the project.

⚠️ Important Notes

• HAFC does not replace a filament runout sensor
• It acts before, by intentionally cutting the filament
• No electronic adjustment required
• Works independently of printer brand

❤️ Support & Feedback

If you use the HAFC:

• leave a like ❤️
• post a photo 📸
• share feedback (positive or critical)

👉 This is what will enable V2 and V3.