One of the best parts of building a coil gun is seeing just how fast you can get that slug to move through the air. [Daniel] built this speed meter to be able to see exactly that. It is comprised of two optical sensors, one at each end of a barrel. As the projectile passes them, its speed is calculated using an Atmega16. Since the distance between the sensors is pre determined, its only some simple math to figure out the speed of an object passing between them. The result is then displayed on a nice looking blue LCD.
If the blue accent lighting and acrylic stylings look familiar, that’s because we’ve seen [Daniel] before. He’s the one that built the portable coil pistol.
TechEBlog has posted a few pictures of a student constructed coil gun. It’s bolt-action and includes a six round magazine. The gun only has a single stage to accelerate the projectile. While not as impressive as the portable coil pistol, it’s still more fun than most shop projects we’ve seen. You can find a video of the device below.
Continue reading “Bolt-action coil gun”
[Daniel] had to have runaway in his mind when he built this coil gun. It’s hand held, holds 14 42 gram rounds and can propel them at speeds of 110km/h. Of course when it is battery powered, you have a 90 second warm up time between shots. It can also be used while plugged into a wall socket, which reduces the charge time to roughly 3 seconds. Great job [Daniel].
[thecapacity] sent us his iobridge project where he controls a coil gun with a Wiimote. To make the coil gun, he took apart an office golf putter that had a ball return. The mechanism to return the ball is a metal cylinder that is moved magnetically. He simply replaced the cylinder with a smaller diameter piece of metal to create the gun. His computer monitors the Wiimote axis changes and sends them to the ioBridge. The unit could be located anywhere, but without a camera on it, he’ll have a hard time aiming. There’s a video of it working after the break.
Continue reading “Wiimote controlled coil gun”
[rocketman221] wrote up one of the simplest ways to build a high voltage power supply. This one in particular was used on his coilgun. Instead of building a custom circuit, he’s using flash charging boards from disposable cameras. Six 450V 470uF caps are wired in parallel to make up the bank. Two of the charger boards are wired to one switch to initiate the charging process. Four additional boards are wired two a second switch for the second charging stage. The part cost on this is incredibly cheap and it only requires a 3.3V input to reach 450V. The writeup has plenty of warnings about the dangers of high voltage; you need to clean off all flux residue to prevent arcing across the circuit boards. Embedded below is a video of the bank being discharged through several objects. Continue reading “Easy high voltage power supply”
The Leyden jar capacitor posted the other day fails to compare to what [FastMHz], one of the members over at the 4HV.org forums, has been busy building, a 24kj capacitor discharge bank. This capacitor bank will be configured for 4500v @ 2400uF and can be charged up slowly using microwave oven transformers. It can then release all its stored energy in under a millisecond through a triggered spark gap. This allows for some pretty big sparks as seen in this video, we are not sure about the laughing in the video maybe the power has gone to his head? Continue reading “24kJ Capacitor Bank”
[Andrew] sent in his low voltage coil gun. He used some control hardware that most hardware hackers probably don’t have on their shelf, bit it’s still a good proof of concept. Each coil is driven by a dedicated relay, and a PC power supply feeds the system juice, while a programmable logic controller does the work. Since it’s just a matter of triggering the coils in order, the PLC could be easily replaced by a micro controller.