#HTE

An Unusual Design for a DIY Spring-Action Knife Sharpener

This is a very creative way of turning lemons into lemonade. John Heisz accidentally dropped and broke his oilstone, rendering it useless. But then he devised a way to repurpose it by cutting it up and building a spring- (actually sponge-) loaded contraption to turn it all into this nifty knife sharpener:

http://www.core77.com/posts/71319/An-Unusual-Design-for-a-DIY-Spring-Action-Knife-Sharpener