Credit Card-Sized Utility Knife - 9mm Blades

1. Blade Mechanism

• The blade extends/retracts via a sliding button with controlled resistance to prevent accidental deployment.
• Audible "click" feedback is provided during sliding (multi-stage engagement confirmed).

2. Dimensions & Compatibility

• Exact credit card footprint (85.6×54mm) with 6mm thickness (slightly thicker than standard cards).
• Blade Compatibility:
  • Designed for 9mm-wide utility blades (e.g., Stanley 11-300T-22: 9mm×85mm).
  • Modification Required: Snap off the first 3 segments (~15mm) to fit the compact frame.

  • Pro Tip: Ideal for repurposing used blades!

    

3. Material & Calibration

• Tested with PETG/PLA - both functional but may exhibit varying shrinkage (risk of over-tight assembly).
• Included Backup Parts (in .3mf files):
  • Low-friction Slider: Reduces sliding force if primary part feels stiff.

  • Looser End Cap: Easier installation if original cap fits too tightly.

    

Printing Instructions:

Supports needed—peel-off easy! But DON'T skip the ones I added manually. They're there to save your print!

Assembly

All parts displayed

Insert blade & slider from rear
→ Critical: Press blade flush against top of knife casing!

Extend blade 3 notches beyond casing (~15mm)

Snap off blade segment
→ Use grooves on end cap or pliers for cleaner break

nstall end cap. Done!

The strength of 3D-printed knives cannot be guaranteed and they are suitable only for light-duty tasks, such as cutting paper or opening Amazon packages. Unless otherwise specified, all of my knife designs are intended for light-duty use only.

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