This is doorstop that I designed in Sketchup as my first fully homemade 3D print... thought I'd upload it since I had it sitting around. It's 40 x 40 x 120mm so not huge, but probably bigger than it needs to be unless you had a really big gap under your door! The bottom surface is designed to grab onto carpet without damaging the pile and the top is stepped to grip the bottom of the door nicely.