MagicExpand Pencil Case

Design Description:

• This is a magnetic pencil case that expands to double its storage capacity when opened.
• When closed, it measures 56 × 56 × 180 mm, suitable for daily stationery storage and easy to carry.
• It can stand upright on a desk, helping save space.
• The exterior design is clean and minimal, while more structural details are revealed when opened.
• Inside, there is an elastic divider for holding sticky notes or a class schedule.
• The back features three integrated printed pivot joints, providing high strength and structural stability.
• Magnet size: D5H3 or D6H2.

Materials & Printing Recommendations

For the MAIN BODY, PLA Basic is recommended.

• PETG is not recommended, as it may shrink slightly after cooling, which can affect overall dimensional stability.
• PLA Silk and PLA Metal may have reduced layer adhesion due to additives, increasing the risk of cracking. Strength can vary between different brands and colors, so if you plan to use them, it is recommended to print a small test piece first.
• Non-enclosed printers may produce misaligned closure seams in winter due to uneven cooling; keep ambient temperature above 25 °C.

Hinge Options (Three Solutions)

Hinge Option 1: One-Piece PETG Hinge

• Print using PETG with a 0.2 mm nozzle.
• This version requires no glue and is the simplest to assemble.
• Please maintain the original print orientation and settings.
• A 0.2 mm nozzle is required. Using a 0.4 mm nozzle will increase bending resistance and may prevent the case from fully closing.
• PETG should be properly dried before printing. High moisture content can make the part brittle.
• During the first fold, bend slowly along the designed direction to reach the working angle. Avoid bending too quickly to reduce internal stress.
• After the initial conditioning fold, the material will enter a stable working state.
• Ensure the foldable part is fully folded into position before installation.
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Hinge Option 2: TPU Sandwich Structure (Recommended)

• The inner bendable tab should be printed in TPU using a 0.4 mm nozzle
  The outer shell layers can be printed in PLA or PETG using a 0.4 mm nozzle. (a 0.2 mm nozzle can improve fine detail).
• Using TPU for the flex layer provides the best flexibility and durability.  It remains stable even in low temperatures.
• B-7000 E-8000 or UHU-type adhesives are recommended. They cure clear and remain slightly elastic, which works well for moving structures.

• See the assembly diagram below for detailed instructions.

   

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Hinge Option 3: PLA Sandwich Structure

• The inner bendable tab should be printed in PLA using a 0.4 mm nozzle (a 0.2 mm nozzle can improve the smoothness of the top surface).
  The outer shell layers can be printed in PLA or PETG using a 0.4 mm nozzle  (a 0.2 mm nozzle can improve fine detail).
• Flexibility and durability are moderate.  The PLA in the sandwich structure shows significantly better performance than the one-piece PLA hinge.
• In low temperatures, the hinge may become stiffer, but it will not snap under normal use.
• The inner bendable tab differs in thickness between PLA and TPU versions and cannot be swapped.
• Assembly is the same as the TPU version.
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Divider Section
The divider is used to hold notes or a class schedule.
If a divider is not needed, the triangular plug provided in the files can be used instead. It is recommended to match the plug material with the hinge material.
Materials can be PLA Basic or PETG, with PETG offering slightly better elasticity.
A 0.4 mm nozzle is recommended for printing, while 0.2 mm can be used for finer details.

Installation
Magnets need to be secured with glue.
The divider and hinges are installed via a friction-fit and do not require glue.

• UPDATE 20241119

  1 Print parameter of PETE folded plate  has been improved.

  2 Adjusted the thickness of the TPU part， now thinner, softer and easier to align and paste.

  3 Support pattern angle adjust, easy to remove with a knife or flush cutter. 

• UPDATE 20241128

  1 The folded plate of the pencil case has been optimized in terms of design and parameters, enhancing its thickness and bend strength to better withstand 90-degree folding.

  2  The folded plate can now be directly inserted into the pencil case without the need for glue. This allows you to easily switch to your favorite colors or replace damaged plates whenever needed.

  3 TPU solution optimized

• UPDATE 20250910

  Based on user feedback, I added a version without magnets. In this version, the opening edge has been slightly modified to look more lively, and the elastic mesh inside has also been adjusted a little.

• UPDATE 20250917 

  Added 6×2 mm magnet version

• UPDATE 20251019

  Added a 20cm lengthened  version without magnets

• UPDATE 20251026

  The thickness of the TPU sheet has been optimized to reduce the risk of damage during printing and removal, and the clip structure has been improved.

• UPDATE20260214 

  Added Option 3 for the hinge section – PLA sandwich structure.