Does your drill go as fast as the manufacturer says it will? Well, you’d need a tachometer to figure that out. They’re not that expensive to buy, but as [Elite Worm] shows, they’re not that expensive ...

To measure how fast something spins, most of us will reach for a tachometer without thinking much about how it works. Tachometers are often found in cars to measure engine RPM, but handheld units can ...

We all like cheap items off eBay especially if they do cool and unusual things, sometimes we get so carried away by the price that we do not even realize that fact that we do not know anything about ...