When you push or pull with a simple machine, you are applying a force and doing work. And, if you get more force out of a machine than you put into it, then that machine has a mechanical advantage.

Lead screws are one of the most common linear-motion devices, thanks to their low cost and reliability (see "A Short History on Ball Screws"). And recent advances in modern machining can make them ...

While single-screw extruders perform the lion’s share of recycling applications, twin-screw machines have a lot to offer recyclers—especially when the goal is a higher-value end product. Are ...