He never mentions what the part is going to be used for, but at 376 x 376 x 250mm (14.8 x 14.8 x 9.84in), he estimates that this is the biggest single part printed with a DIY 3D printer.

This Low Cost, Open Source, LCD based SLA 3D Printer design by [Dylan Reynolds] is a concept that aims to make DIY SLA 3D printing ... with whatever part or parts they wish.