[Adrian] came across a treasure trove of 507 mechanical device designs. It didn’t seem quite right for a Retrotechtacular post, but we wanted to share it as it’s a great place to come up with ...

For the price of a mid-range Android phone, [Kenneth Finnegan] turned a 50 caliber ammo can into a 50 amp-hour ... All it took to fit them in the case was to grind off the spacers’ dovetails ...