Adapted from a tool I saw in this video:
It is quite long so I will attempt to get the point in my instructions.
Clamp a glass cutter within this setup and you'll quickly have the ability to turn empty beer, wine, etc., into useful things like drinking glasses.
I have an idea for how the top end of wine bottles can be used, so don't go throwing away those bits yet. Kinda building up to something here ;)
All the bolts in the diagram are M4x20mm, and there's a 30mm piece of M8 studding holding the 608 bearing in place.
- Bolt and Print (or adhesive, melt, whatever) the parts together as per the picture.
- Fit a bearing of whatever size you like.
- Clamp a glass cutter in place.
- Fix them so that a bottle can easily turn on both points of contact.
- Adjust the conical plug so that the cutting wheel is at the height you wish to cut away.
- Turn the jar through ONE rotation on the blade to make a single small score all the way round.
- Carefully dribble some hot water over the score line.
- Dribble some cold water over the score line.
- Continue to alternate the last two steps until the heat pressure pushes the fracture through along with the jar comes apart.
- Sand/grind down some remaining sharp edges.