ThinkFun- a simple Corner connector and a Cross connector.

thingiverse

This is a basic building block, essentially a simple connector and cross-over joint. I needed an easy way to upgrade my complex contraptions, so these versatile connectors helped me increase the standard array of parts. They enable expansion on both sides, effectively doubling the original quantity. Directions: Print two sets of each model, then firmly fasten them together. This simple solution easily enhances your standard ThinkFun's connector pieces. These modules will seamlessly fit all components and sections from ThinkFun kits. A simple tap of the "Like" button (the heart icon) is greatly appreciated!