Letter Opener

Magnetic Envelope Opener – Original Design (Idea Inspired by Midori)

This is my own original 3D-printed magnetic envelope opener.

The idea came from the Midori magnetic opener, but the entire design, mechanism, dimensions, and internal system are fully my own work.

The model is larger and easier to hold, and it uses a single small piece of a razor blade as the cutting edge.

Parts Breakdown

Printed Parts (4 pieces total):

1. Main body (1 piece)
2. Upper blade holder (1 piece)
3. Lower blade holder with integrated spring (1 piece)
4. Blade holder cover / cap (1 piece)

Extra parts required:

• 1 piece of razor blade (cut from a standard utility blade)
• Six round magnets (6 × 4 mm) for the back

The lower blade holder’s integrated spring keeps the blade under tension.

How It Works

The two blade holders clamp one small piece of razor blade inside the main body’s cutting channel.

When you slide the top edge of the envelope through the center slot, the blade cuts it open smoothly.

Safety tip

• The razor blade inside has a 2 mm cutting height.

• Shake or tap the envelope so the contents fall to the bottom before opening.

   

Print Information

• Print with supports
• Dimensions: 160 × 80 × 20 mm
• I used ABS
• Blade holders and cap are press-fit 
• Magnets fit into the rear pockets

Overview

A clean, functional magnetic mail opener that stays on your fridge or filing cabinet.

Simple to assemble, easy to use, and designed completely from scratch with inspiration only from the magnetic concept.

Fill free to redesign and improve on design.