66% or better

Open source artillery

Thanks to [Josh, Kyle, and Mike], it is now possible to wage (Nerf) war with an Arduino. The turret designed around it is capable of shooting 6 foam projectiles in close succession, between reloads. The faux weapon interfaces with a computer through the Arduino’s onboard serial link (via USB). Software on the PC sends commands to the Arduino, which then executes functions, such as panning, tilting, firing, and rotating the cylinder. The power for the firing itself comes from a 5 gal, 80 psi air compressor. The Java software on the host PC also does smarter things, like show streaming video from the turret’s webcam and even performs basic object tracking (with mixed success). All the code for building the brute is available on [Josh's] website.

Dry Ice Cannon

[Alexander] sent in his entry into a “creativity contest” at his university. He and some friends put together this dry ice cannon.  Take note of the creative mechanism they used to mix the water with the dry ice. A large amount of gas is expelled as soon as the two begin to meet. If the gas is supposed to escape through the same opening, it is difficult to get all the material through. They have added a second opening just for the exhaust during mixing. Great job guys. How about some downloadable plans.

Building the Shmooball cannon

shmoo

We’ve been eagerly anticipating this, [Larry] has published the entire build of the Shmooball gun for 2009. This design is more compact and elegant than the one for 2008 and has a slightly more Ghost Buster’s aesthetic about it.  The pictures are great and there’s lots of good tips along the way. We can’t wait to see what they make next year. How about a gattling version?

Replacing a point and shoot lens

cockeyed

Cockeyed.com is a peculiar site. It is spattered with links in an almost unintelligible manner, but if you dig hard enough, or just click randomly, you can find some pretty fun stuff. One nice writeup they’ve done is how to replace the lens in their point and shoot camera. This one happens to be a Canon Powershot sd750, but it will give you an idea about how difficult it can be for any point and shoot. The lens assembly couldn’t be replaced until almost every single piece had been disassembled. There are tons of pictures showing the process and the final result. Though the install was a success, his replacement lens was already beat up pretty bad. Looks like he’ll have to go through it all again.

[via The Old New Thing]