Overview:

I wanted to speed up the process of preparing PET bottles for making filament. One of the steps is to cut the bottom of the bottle. Using scissors is not very convenient and fast so I have designed this cutter which uses a snap-off blade. The blade is rotated by hand using a simple crank mechanism.

The PET_Bottom_Cutter_Insert.stl is added for smaller bottles (1.5l) with diameter ~88mm. For these bottles it is beter to use the short version of the blade holder - PET_Bottom_Cutter_Blade_Holder_18mm_Short.stl.

Here you can see how I'm using the cutter:

Bill of Material:

• Base
  • Plywood ~300x120x18 mm
  • 4x Corner_Protector.stl (Optional)
  • 4x Screw 2.5x12mm (Optional)
    
• Cutter
  • 1x PET_Bottom_Cutter_Crank_Base.stl
  • 1x PET_Bottom_Cutter_Crank_Spacer.stl
  • 1x PET_Bottom_Cutter_Crank_Handle_Distance.stl
  • 1x PET_Bottom_Cutter_Crank_Handle_Arm.stl
  • 1x PET_Bottom_Cutter_Crank_Handle.stl
  • 1x PET_Bottom_Cutter_Blade_Holder_18mm_Long.stl or PET_Bottom_Cutter_Blade_Holder_18mm_Short.stl
  • 1x PET_Bottom_Cutter_Socket_Wrench.stl (Optional)
  • 2x Bearing 608ZZ (8x22x7mm)
  • 4x Screw 4x25mm
  • 1x Screw M8x100mm
  • 1x Screw M8x50mm
  • 2x Nylon Lock Nut M8
  • 2x Nut M8
  • 2x Washer M8
  • 1x Nut M3
  • 1x Screw M3x10mm
  • 1x 18mm snap-off blade
    
• PET bottle support
  • 2x PET_Bottom_Cutter_Support.stl
  • 1x PET_Bottom_Cutter_Insert.stl
  • 4x Screw 4x25mm