Funnels and Channels
One form of invention that sorts LEGO by size consists of a system of funnels or channels that LEGO blocks slide through. Carefully calibrated holes or trapdoors let blocks of a certain size fall through while larger blocks slide on into a different channel or container. Progressive layers of channels and sorting holes redirect the blocks into a set of containers by size category. This method will not separate blocks by color or specific type.
Human-Directed Sorters
Another type of LEGO sorter depends on human instructions. You can create a system that releases one block at a time from a bin of blocks to be sorted. The user then indicates which bin the piece should end up in and the sorter responds by mechanical means or programmed electronics. This method allows maximum control but is quite slow. It may be best combined with other systems to deal with unusual pieces the automatic system could not make sense of.
Storage Systems
Sorting LEGO blocks also involves creating a storage system that leaves pieces easily accessible according to certain properties. This can range from a few broad categories to a whole array of tiny drawers, each set aside for a single size, shape and color of block. Whatever the case, sorting blocks does no good if you cannot store and access your LEGO blocks according to the qualities you sorted by in the first place. The key is to maintain access to the distinctions made during sorting.
Storing by Building
A simple, intuitive and attractive way to store your sorted blocks is by connecting like blocks into constructions of their own. Create a wall of blue blocks two units wide or an array of all the wheels you own. This method is highly flexible. Since LEGO are made to connect to each other, you can build many categories of blocks into their own structures. This method works especially well if you'd rather sort by LEGO set than by size or shape, and the results can be left on display instead of tucked away in buckets and drawers.