Everybody knows about Lego sets, but not everyone can afford them. Thankfully, there are other brands that also produce high-quality building sets. For instance, this Mould King model engine kit is ...

Hack A Day’s very own [Jeremy Cook] was trying to figure out how to push four ‘arms’ out one at a time. What he came up with is a very nice model of a radial engine. Everything was cut on a CNC router ...