Cut slotted steel to desired length and assemble with these printed parts on 12mm linear rods. Build whatever size printer you want. The one pictured prints 12" cubed. Many of them are Remixes or modifications of Printrbot Plus designs by others: Remix of: http://www.thingiverse.com/thing:832468 Remix of: http://www.thingiverse.com/thing:643475 Remix of: http://www.thingiverse.com/thing:339763