SawStop is a safety feature that immediately stops and retracts a spinning saw blade if it comes in contact with anything that even remotely resembles your finger. Check out the startling video above, where it practically self-destructs in order to save this innocent hot dog's life. If that were actually your finger, you would escape with just a scratch and maybe need a stitch or two rather than running around your woodshop looking for your finger.
How does it work?
The SawStop safety system includes an electronic detection system that detects when a person contacts the blade. The system induces an electrical signal onto the blade and then monitors that signal for changes. The human body has a relatively large inherent electrical capacitance and conductivity which cause the signal to drop when a person contacts the blade. Wood has a relatively small inherent capacitance and conductivity and does not cause the signal to drop. A fast-acting brake stops the blade when contact is detected.
This invention has been around for a half a decade, but we're wondering why every saw in the world doesn't have this technology on board. It's not a retrofit; a saw must be built around this mechanism. How many fingers have been lost since its invention, because manufacturers were afraid the extra $100 it would add to the cost of the saw might drive buyers away?
Product Page [SawStop, via TGISFW]