2x1 building blocks

My little brother has gotten to the point where simple building blocks aren't advanced enough for him to use so I designed him this system of connectors for 2x1. Most of the blocks can print without supports you might want to print them solid so that they won't break. After you print al the pieces you want, you need to cut some 2x1 int the lengths you want some good lengths are 3" 2' 4'. Then start building!