As for the why, I’d agree it’s half for the fun of it, half for smelting.
Aluminium cans aren’t the cleanest things to cast with, but they’re still alright from time to time.
I guess it’s a matter of how much aluminium can you buy if you just traded all the cans in, if you’d get more trading in and then using that money to buy aluminium then sure, this is a BIT silly, but still, I end up with a fair few cans I can’t trade in anyway, so why not?
I’ve played with the idea of a can crusher for a while, and while pneumatic pistons are probably the most reliable (https://www.youtube.com/watch?v=DYM9kJFZgmg), they need fancy skills like “Welding” and “Knowing what you’re doing”, neither of which I have.
There were two options I came up with, one was using the “Transmission” from a DeLonghi superautomatic espresso machine (Bean-to-cup), of which I have boxes full of the (somewhat used) things back in Victoria (from one of my old jobs). Link to image
They have more than enough grunt to snap bone clean in half, I’m sure they’d have no problem with tin cans (Or, depending on your approach, comically lifting a sledgehammer to drop on the cans)
Online, new, they’re pricey, but if my old boss is on friendly terms with me, they’re actually pretty cheap (Plus I need to talk to him about getting a heating element for the broken DeLonghi that’s been donated)
The other option was something I’ve come across more recently, 12V electric car jacks (See )
There are numerous forms of these around, and while comically slow they would at least serve as a linear actuator with the forces needed to crush an undented can.
If someone has access to pneumatics, then I’d say that’s the way to go, but these are some other options that may be of use.