PET bottle 608ZZ bearing cutter adjustable

thingiverse

On the internet there are lots of designs of PET bottle cutters to make ribbons recycled into eco-friendly and economical filament for DIY printing. Bearing cutters are a little more complicated to make but they are more effective and easier to use than fixed blade cutters. I am joining the crowd with a design which uses common 608ZZ (22mm) bearings. There are many videos on line showing how to grind the bevel on bearings to make them sharp for cutting. I am not going to reinvent the wheel and repeat the process here. I normally design and make things in metric. However, it is difficult to get metric sized hardware here, so I use imperial sized hardware instead. This can be easily remixed to metric dimensions if required. This design uses two 5/16" threads to mount two bearing cutters, secured with two nuts, one above and one below. A ribbon width guide with a smooth 13/16" hole is slid onto a third 5/16" thread. This guide can move up and down, and fixed with a threaded knob underneath and a locking nut above. A 1/4"(or alternatively 6mm) hole allows a depth gauge to mark repetitively used ribbon width.The gauge is simply a short length of bamboo chopstick sanded to tight fit within the slotted hole in the guide. Once the depth is set, you can replace with a longer chopstick to serve as the prop-up for the bottle. The three long threads are mounted onto a base which is a small block of hardwood with holes tapped 17/64" separated 0-20mm-50mm apart, and bolted at the bottom. These dimensions are critical. The hardwood block provides rigidity. This base can be printed if preferred. Material Nylon (or PETG with change of slicer settings) Temperature 265°/75° Cooling none Nozzle 0.6mm Layer height 0.16mm Line width 0.5mm Tolerance exclusive Adhesion brim 10mm (to help prevent warping) Enclosure preferred