They’re relatively simple contraptions, and a common enough DIY project. But even still, this largely 3D printed rock tumbler from [Fraens] is unique enough to stand out. To make a basic rock ...

I tried the Tumbler Knife Sharpener(a popular magnetic, amateur-friendly tool) for about a month, using it to sharpen knives for cutting meat, vegetables and fruit to see how effective it was.

They’re relatively simple contraptions, and a common enough DIY project. But even still, this largely 3D printed rock tumbler from [Fraens] is unique enough to stand out. To make a basic rock ...