This 3D printed part is a Clamp that is used to connect to an aluminum Cookie Sheet Pan so that it can be used as a build plate in a 3D printer. You will need two nuts and bolts to secure the Clamp to the Cookie Sheet round rim. Cookie Sheet Pans are stamped out in a metal press and some are fairly flat. They make some that are really nice and flat on the bottom. The Cookie Sheet Pans are low cost and they will trigger inductive sensors that are used in auto bed leveling for 3D printers. Cookie Sheet Pans come in a variety of sizes and with some Blue Painters Tape might make a good low cost build platform for a low-cost 3D printer.
This 3D part was designed using the free software package eMachineShop.