The SLUK (Slim Logical Utility Knife) is an ultra-compact, fully 3D-printable utility knife designed to be as small, slim, and practical as possible while still using a standard utility blade.

This design focuses on simplicity, safety, and everyday carry usability. It uses a compliant locking slide to positively lock the blade in both the open and closed positions, and assembles without screws or hardware using a snap-together construction.

The SLUK is designed for people who want a minimal utility knife that can live on a keychain, in a pocket, or clipped onto a bag without bulk.

• Uses a standard utility blade
• Compliant locking slide controls blade movement
• Blade locks open and closed
• Optional snap-on clip
• Integrated keyring hole
• Fully snap-together assembly

• Ultra-slim, compact utility knife design
• Uses a standard utility blade
• Compliant locking slide locks blade open and closed
• Fully snap-together, no hardware required
• Optional snap-on clip
• Integrated keyring hole
• Designed specifically for 3D printing

Opening the Knife
Press the thumb grip up, then slide it forward until the blade is fully extended and locked.

Closing the Knife
Press the thumb grip up, then slide it backward until the blade is fully retracted and locked.

The compliant locking mechanism provides clear tactile feedback at both end positions.

Assembly is simple and requires no tools:

• Carefully remove the small printed support from the blade carrier (shown in orange in the images)
• Seat the utility blade into the blade carrier until fully seated against the blade notches
• Place the blade carrier with blade into the main body
• Slide the lid into the main body until fully seated and locked
• (Optional) Snap the clip onto the rear of the body

• Length: 94 mm
• Width: 25 mm
• Thickness: 6 mm (front), 11 mm (rear / clip area)

Functional designs require stronger settings than typical decorative prints. Recommended settings:

• Material: PLA, ABS, or ASA
• Nozzle Diameter: 0.4 mm
• Layer Height: 0.2 mm
• Line Width: 0.4 mm
• Walls: 4 (1.6 mm)
• Top / Bottom: 5 (1.0 mm)
• Detect Thin Walls: On
• Wall Generator: Arachne
• Infill: 40% Cubic
• Brim / Raft: No
• Support: None required
• Print Orientation: As per STL / 3MF files

Related Links

Join the LogicalPlanet Discord
https://linktr.ee/logicalplanet

Visit my blog for more details and other designs
https://www.logicalplanet.com/

Revisions and Updates
I occasionally update and revise my designs. When I do, I’ll document the changes here. Check back periodically for the latest revision notes or if you’re experiencing any issues with a model. Please email me at logicalplanet3d@gmail.com if you would like me to make a revision or have comments about this design.