66% or better

Recurve bow make from wood and skis

bow-made-from-ski

A little face protection is a great idea when first testing out your homemade bow. [Austin Karls] made this recurve bow during what he calls an engineer’s Spring break.

He settled on the idea after seeing a few other projects like it on Reddit. After first drawing up a plan he headed down to the shop to cut out the wooden riser (the middle part of a bow). Unlike traditional recurve bows this is made up of three parts. Traditionally you would laminate different types of wood to achieve the flexibility and tension levels desired. But [Austin] went with a synthetic material: the tips of two skis. Each were cut to the final length and affixed to the riser with a pair of bolts.

After a few test shots he gained confidence in the design and did away with the face mask. Now if you’re in the market to take your existing bow and add some firepower to it you’ll want to look in on this shotgun enhanced compound bow.

[Thanks Schuyler]

Virtual Archery game makes practicing convenient, safe, and inexpensive

Virtual-Archery

Inspired by playing The Legend of Zelda video game series, Cornell University students [Mohamed Abdellatif] and [Michael Ross] created a Virtual Archery game as their ECE 4760 Final Project.   The game consists of a bow equipped with virtual arrows and a target placed about 20 ft away. The player has three rounds to get as high of a score as possible. A small display monitor shows the instructions, and an image of where the shot actually hit on the target.

Pressing a button on the front of the bow readies a virtual arrow. A stretch sensor communicates with a  microcontroller to determine when the bow string has been drawn and released.  When the bow is drawn, a line of LEDs lights up to simulate a notched arrow. The player aims, and factors in for gravity. An accelerometer calculates the orientation of the bow when fired. The calculated shot is then shown on the display monitor along with your score.

This immediately makes me think of Laser Tag, and feels like a product that could easily be mass marketed. I’m surprised it hasn’t been already. Good work guys.

[via Hackedgadgets]

Check out the video demonstration after the break:

[Read more...]

Building a Yagi-Uda antenna

[Tommy Gober] built this Yagi-Uda antenna that has some handy design features. The boom is a piece of conduit with holes drilled in the appropriate places. The elements are aluminum arrow shafts; a good choice because they’re straight, relatively inexpensive, and they have #8-32 screw threads in one end. He used some threaded rod to connect both sides of the reflector and director elements. The driven elements are mounted offset so that a different machine screw for each can be connected to the appropriate conductor of the coaxial cable. The standing wave ratio comes in right where it should meaning he’ll have no trouble picking up those passing satellites as well as the International Space Station.