A small access problem
This project started with the difficulty of pulling cards out of a compact holder. I developed a wallet layout around easier card access, then turned that requirement into a mechanical design concept.
The challenge was to make room for reaching and removing a card while keeping the holder compact. It helped me think about the movement the user needs before choosing a mechanism.
Making space for the cards
A basic packaging check is:
n is the number of cards, t is card thickness, and c is the clearance allowed for the stack. This simplified relationship explains one of the layout constraints; it is not a manufacturing tolerance specification. Card access also depends on where the fingers can reach and how the stack is supported.
The completed work was an early design concept for easier card access. It was not a mass-produced product or a formal user study. The photograph above is a third-party card holder used as a reference for the topic.