Stops your RepRap I2 slowly taking a walk across your desk. Simple as that.Print in TPU or your favorite flexible filament. Remember the rules of flexible filament:- Print slowly and at a constant rate so as not to vary the pressure in the hot-end or cause a ruckus. Typical flexible filament speeds I've been achieving are 19mm/s, much more and I end up untangling my extruder. Print with the fan OFF. Too much heat and you're print will curl, too little and your extruder will tangle in filament. Don't be shy, use a large layer height and extrude on the thick side. Print 4 of them. Some of you might need to print this part with a brim or whatnot otherwise it may curl at the edges. I included the FreeCAD file so you can change it anyway.