You can use the PET Bottle Cutter to cut sprips from the PET bottles with selected width. The width is defined by spacers which are put under the blade. The PET strip can be then used in machine which converts it to filament for 3D printers.

I'm using this bottle cutter for some time and it works very well. You will gain the skill after a few bottles.

The metal sheet from the bottle can protects the plastic body because the edges of the bottle and strip are quite sharp and can scratch the plastic.

Bill of material:

• M8 screw rod with length about 40-45cm
• 2x M8x40 screw
• 4x M8 nut
• 4x M3.5x20 woodscrew
• 9mm cutting blade
• Bottle can

Assembly:

• Print all the parts (M8 nuts are inserted inside the knobs during print)
• Cut the bottle can sheet according to the template
• Wrap the sheet abound the body
• Insert the nut and screws inside the body
• Insert the needed spacers
• Put the cutting plade on the spacers and prot it up agains the screws
• Add the rest of the spacers and tight them with the knob
• Add the screw rod to support the bottle

You can follow the photos.

Here you can see how I cut a bottle using this cuter: