The Stringhammer (patent: US 9,997,145 B1) is a fun new tool for guitarists, bassists and anyone who plays a plucked string instrument held sideways... e.g. banjo, mandolin, ukelele, etc. It allows you to use an ordinary pick and play as you normally play, and be able to switch at any moment to a hammered sound similar to hammered dulcimer, santour (aka santur, santoor) or kanun (kanoun) and back again at any moment. It turns your instrument into two instruments, without having to learn a whole new one!
Just clip your favorite pick into the ring and you're ready to go!
Hold the pick normally when plucking the strings, as usual.
When hammering, you can stay in normal position, or move your thumb up slightly to grip the spring. Holding the spring allows you to control the hammering speed: twist the spring to increase the speed, relax to slow down. The combination of the weight of the brass striker and the spring action cause the solid brass striker to bounce off the string or strings (you can play one or two strings at a time) while holding the instrument normally. Don't lay your instrument flat like a dulcimer... it won't work! To change between playing a single string and playing two strings, just tilt your hand to change the angle that the striker hits the strings.
Unlike an effects pedal, it doesn't need batteries, and works with acoustic as well as electric instruments. It allows for as much expressive nuance as a pick, and it's in addition to your pick, not a replacement for it.
It fits in your pocket, and it's built to last. The parts are connected together in a process called brazing, which is kind of in-between welding and soldering. The brazing points are reinforced with a super strong, high-impact epoxy.
The possibilites are unlimited... you can find ways to incorporate it into any style, and create a sound that's all your own.