HAFC V2 - Hackman Automatic Filament Cutter V2

HAFC V2 – Hackman Automatic Filament Cutter

by Hackman3D

Here's a link to get the necessary hardware. No partnership or affiliation involved, but since the price is reasonable, I haven't asked for a commission.

HAFC Aliexpress Pack back in stock :

https://a.aliexpress.com/_EH25h7a

Video in use, sorry it's on a Bambu printer, I work on an holder for my prusa mini

https://www.youtube.com/shorts/-0ykCtMGRbw?feature=share

🧠 Concept & Purpose

The HAFC V2 (Hackman Automatic Filament Cutter) is a fully mechanical system compatible with any FDM 3D printer using 1.75 mm filament with a PTFE tube.

I designed it to solve a very common issue:

filament getting stuck on the spool (tangles, friction, jammed spool…).

Instead of forcing the extruder:

•filament tension increases

•the mechanism triggers

•the filament is cleanly cut

•the printer pauses thanks to its filament runout sensor

👉 You just reload filament and resume the print

No electronics, no sensors involved —

everything is passive, simple, and reliable.

⸻

⚙ What’s new in V2

This version is based directly on feedback from V1.

The main focus was improving reliability and behavior:

•more compact design

•faster to print

•improved tolerances (filament path + internal sliding)

•added return spring → automatic reset

•stronger resistance to reduce false triggers

•improved magnet alignment

•possibility to add extra magnets externally to fine-tune trigger force

The result is a more stable and predictable system, even on very precise machines.

⸻

⚙ How it works

The filament goes through the HAFC using a PTFE tube and Pneufit connectors.

If the spool gets stuck:

•tension increases

•the sliding module moves

•the blade cuts the filament

➡ The printer detects filament runout and pauses automatically

Magnets control the trigger force,

and the spring resets the system after activation.

⸻

🖨 Printing

•PLA or PETG recommended

•supports already included in the 3MF / G-code

Basic settings work fine:

•0.2 mm layer height

•3 walls

•20–30% infill

⸻

🔩 Required hardware

Mechanism

•2 × M6 Pneufit (good quality recommended)

→ cheaper ones may have an internal lip that restricts filament movement

→ Bambu Lab ones work perfectly

•1 × Bambu Lab cutter blade for X1/P1/A1, No P2S

•1 × spring (0.3 × 6 × 80 mm)

•3 to 5 × 8×2 mm neodymium magnets

Screws

•2 × M3×20

•1 × M3×12

⸻

⚠ About Pneufit installation

When installing the Pneufit on the moving part:

👉 the plastic might crack slightly

This is normal and does not affect functionality.

It depends on your printer tolerances and filament.

⸻

🛠 Assembly

⸻

🔧 Adjustment

Depending on your print, you may need to:

•slide the mechanism manually a few times

•“break in” the contact surfaces

This improves smoothness.

Some users added a bit of grease on V1 —

still an option if needed.

⸻

🔄 Compatibility

•all FDM printers

•1.75 mm filament

•PLA / PETG / ABS / TPU

❌ not compatible with 2.85 mm

⸻

⚠ Important

The HAFC does not replace a filament runout sensor.

It works before failure happens,

by intentionally cutting the filament to prevent a failed print.

⸻

❤ Support

If you use the HAFC V2:

•leave a like

•post a make

•share your feedback

👉 that’s what helps improve the project

⸻

💬 Creator note

V2 fixes the main issues reported on V1:

triggering, smoothness, and tolerances.

Thanks to everyone who tested and shared feedback 🙌

The future versions will depend on the community.

// hidden signal detected

If you’re reading this… you’re not supposed to

A small batch of 8 HAFC V2 kits is being dropped to selected makers.

No public giveaway. No announcements.

Just builders who:

• create

• share

• push the project further

If that’s you… you know what to do.

📩 Send proof of your posts (any platform) in DM.

Selection will be random… but only among those helping the HAFC grow.

// end of transmission 

Instagram link for the giveaway :

https://www.instagram.com/p/DWuOL7CDnDu/?utm_source=ig_web_copy_link&igsh=MzRlODBiNWFlZA==