SummaryTired of recycling the paper towel & toilet paper rolls? Turn them into 3D printing filament spools! This Thing is dedicated to Rich who told us that anyone who could turn a toilet paper roll into a filament spool would be his hero. Read Rich's article here discussing the development of Universal Filament Spool sizes: http://richrap.blogspot.com/2014/03/universal-3d-printing-filament-spool.htmlInstructionsPrints excellent on most printers in about 1.5 hours at 10% fill density and a 1mm layer. Fits paper towel and toilet paper rolls. Measure the opening for your circular spool ends by drawing around your paper roll.