I needed an extra lock for my garden window but there simply isn't one on the market that fits my windowframe.
My neighbour encountered the same problem and made a spacer out of plywood. Sawing, sanding, drilling and painting.
I just made a simple 2 minute sketch, start up the printer, make dinner, and there's my custom part ready to be used and looking like it came right out of the box.

This is why everyone should have a 3d printer in their home. Need it? Make it!