Automating The Bottle Cutter

[Sensei82013]

Some ideas:

- Hot exacto-knife
Basically attach a knife blade to a heating element so it can easily cut the bottle without the need for much torque or relying on the knife to be extremely sharp. The knife would be moved up and down into position by a servo, although the biggest concern is how the attachment to hold the knife and heating element should be made out of metal. PET's melting point is >220C which is well above the melting point of PLA, complicating the material needed for the knife-to-servo attachment.

- Sowing machine piercing motion
The idea here is to have a strong needle or fairly sharp knife pierce the bottle in and out like a sewing machine, making cuts as the bottle rotates in place. This wouldn't require heat to pierce the bottle (at least I don't think so), making the implementation a bit easier with readily available parts. Still a bit tricky to design the tool but seems like a fun and approachable method using a simple DC motor, with the sharp edge coming from the botom as the MG996R servo holds the bottle from the top.