A Solenoid-Triggered Gun

Monday, June 4th, 2007

The NXT servos and other Lego motors are useful actuators, but it’s interesting to explore other actuators. The “Extreme NXT” book by Michael Gasperi, Philo, and Isabelle Hurbain shows how to use many more actuators with the NXT: LED’s, lamps, relays, motors, and a really exotic one called a muscle wire. But it’s always an interesting challenge to find out how to control new kinds of actuators, and it’s often even more interesting to find out ways to integrate them into the Lego/Technic/NXT building system.

In this project I tried to use a solenoid, which is basically an electromagnet that pulls a metal plunger when current flows through it. There were three main challenges in this project: to integrate the solenoid into a Technic mechanism, to find a good use for it in spite of the very short stroke (length of movement), and to drive it either from a motor port or from a sensor port. The difficulty in using a sensor port is that sensor ports cannot provide the high current required to activate the solenoid.

A web page describes the project with pictures and a short video. If you are interested, you may also want to join the lively discussion on actuators in the hardware forum.

Posted in hardware, hacking | 2 Comments »