Based on user feedback I made a larger version for Language Box for use with full-size index cards. 
Please use the link for download and print it! 
 

[Important: I suggest using supports and rubbing assembled surfaces to each other with force as shown in the video. ]

[Important : Card dimensions for the current size shouldn't be larger than the following values:
Height: 4.2 cm
Width: 7.8 cm
If you scale the model, you can scale the card dimensions with the same constant ratio.]


Learning a language using index cards in a sectional box is an effective method that leverages spaced repetition, a powerful memorization technique.

I developed a smart box that can be used for learning languages and building vocabulary much easier and faster. This box is self-locked so it can be carried around without the fear of creating a mess. You can also use the box for storing anything you want. 
 

Here's a detailed guide on how it works:

Introduction to the parts, assembly and operation of the box: 
 

Using The Smart Box for Language Learning

Materials Needed:

• Index cards (half of a standard index card to save space, measure before make size adjustments index card sizes may vary.)
• Language Box / smart box with sectional divisions (Print profiles are available)
• A pen or marker

Steps:

1) Create Flashcards:

• Write a word or phrase in the target language on one side of the index card.
• Write the translation, definition, or explanation in your native language on the other side.

2) Set Up the Smart Box:

• Divide the box into five sections (or however many sections your smart box includes). Label these sections according to the spaced repetition schedule (e.g., Daily, Every 2 Days, Weekly, Biweekly, Monthly).

3) Initial Review:

• Place all newly created flashcards in the first section. Review these cards daily.

4) Spaced Repetition Process:

• Daily (Section 1): Review all the cards in the first section. If you recall the information on a card correctly, move it to the next section. If not, keep it in Section 1.
• Every 2 Days (Section 2): Review the cards in this section every other day. Correctly recalled cards move to Section 3; incorrectly recalled cards return to Section 1.
• Weekly (Section 3): Review the cards in this section once a week. Correctly recalled cards move to Section 4; incorrectly recalled cards return to Section 1.
• Biweekly (Section 4): Review the cards in this section every two weeks. Correctly recalled cards move to Section 5; incorrectly recalled cards return to Section 1.
• Monthly (Section 5): Review the cards in this section once a month. If you recall a card correctly, you can either retire it from the box or keep it for occasional review. Incorrectly recalled cards return to Section 1.

Video describing how to use : 
 

Features of the Smart Box:

• Self-Locking Mechanism: Ensures that the cards are secure and the box can be carried around without the fear of creating a mess.
• Portability: The box is designed to be compact and lightweight, making it easy to carry around for learning on the go.
• Sectional Divisions: Clearly divided to help in organizing the flashcards according to the spaced repetition schedule.

Tips for Effective Use:

• Consistency: Regularly review your flashcards according to the schedule. Consistency is key to the spaced repetition method.
• Active Recall: When reviewing a card, try to actively recall the information before flipping it over. This strengthens memory retention.
• Mix It Up: Occasionally shuffle the cards within each section to prevent memorization based on order.
• Add Variety: Include different types of cards, such as vocabulary, phrases, grammar rules, and example sentences to cover various aspects of language learning.
• Personalization: Customize your flashcards with mnemonics, drawings, or any other method that helps you remember better.

Benefits:

• Enhanced Memory: Spaced repetition helps move information from short-term to long-term memory.
• Efficient Learning: Focuses more on cards that are harder to remember, optimizing your study time.
• Flexibility: You can use this method anywhere and adapt the frequency of reviews based on your learning pace.
• Convenience: The self-locked design ensures that you can carry the box around without worrying about losing or mixing up the cards.

By following these steps and leveraging your smart box, you can make language learning more efficient, organized, and portable.