I love working with metal, but I've always struggled to get perfect 90° bends. Generally, I'll stick the piece to be bent in the vise and smack it around until it's bent. Since it almost always bends crooked, I end up rebending - and generally just making a mess of it.
For my next project I was going to need to bend some cardboard, which inspired me to first tackle a bending brake. Since I knew I would end up bending things much harder than cardboard in the future, I designed the brake to handle thin aluminum and steel.
Inspiration for the design came from several other DIY brakes, such as this one by Improbable Construct and one by the Youtuber JDCD Design. Since I don't have easy access to a welder (and also try to avoid welding as I'm not terribly great at it), I modified the design to make it weld-free.