Files are a very useful important tool if you’re machining your own parts. They can do plenty of shaping themselves on smaller parts in particular. Powering such a tool just makes sense, and a die ...

If you're enjoying this article, consider supporting our award-winning journalism by subscribing. By purchasing a subscription you are helping to ensure the future of impactful stories about the ...

If you enjoyed this article, I’d like to ask for your support. Scientific American has served as an advocate for science and industry for 180 years, and right now may be the most critical moment in ...