CO2 Powered Pinewood Derby Car Is Definitely Cheating

March 15, 2011 by Mike Szczys 37 Comments

The Pinewood Derby is a classic Cub Scout competition where dads and sons come together to build a small-scale race car. You start with a kit that includes a block of wood for the body, as well as four plastic wheels and four nails to act as axles. Most innovations in the ‘sport’ center around reducing friction between the wheels and the axles, and making the body as aerodynamic as possible.

This year [Sliptronic] grabbed an extra kit and threw the rules out the window by powering the car with compressed carbon dioxide. He used a 3D printer to make a housing for two CO2 cartridges that mounts on the center of the chassis. An official Pinewood Derby race track is on an incline and has a wooden gate that keeps each car in place until it is dropped to start the race. [Sliptronic] is using this gate as the triggering mechanism. Springs on either side of the car pull against an arm at the back of the vehicle. This arm is held in place by a rod protruding out the front of the vehicle. When the start gate is dropped that rod releases the trigger, which is pulled up by the springs to pierce the CO2 cartridges. You can see an overview of how that mechanism works in the video after the break.

Continue reading “CO2 Powered Pinewood Derby Car Is Definitely Cheating” →

Automatic Ball Launcher Is For The Dogs

March 15, 2011 by Mike Nathan 24 Comments

automatic_ball_launcher

A while back, [Dino] built an automatic ball launcher for his dogs, but he wanted to revise it to make it smaller and a bit more user-friendly. While watching an episode of “Prototype This”, he came across a great idea to improve his launcher, so off to the workshop he went.

He repurposed a power window motor from a car, and mounted it to some wood-reinforced aluminum sheeting in his garage. He added a piece of aluminum tubing to serve as a spring-loaded launch arm, which is drawn back by a small lever attached to the window motor.

When a ball is dropped onto a switch at the bottom of the launcher, the window motor starts turning, which pulls the launch arm back into place. Once the arm reaches the tipping point, the spring snaps it forward, launching the ball across the yard. The lever attached to the window motor eventually makes its way back under the launch arm, and is stopped by a switch that is also attached to the motor.

After the prototype was finished, he added some more wood to protect the mechanism from his dogs and vice versa. A hopper was added to the top of the structure to allow the dogs to load the launcher themselves, after a bit of training.

Now, some of you might wonder what is wrong with [Dino’s] arm. Truth be told, it works just fine. If you are a frequent Hack-a-Day visitor, you know that he spends plenty of time in the workshop, so this is an easy way to let the dogs entertain themselves until their owner is ready to play.

Check out the video embedded below for a demonstration of the launcher, as well as a detailed walkthrough of how the mechanism works.

Continue reading “Automatic Ball Launcher Is For The Dogs” →

DIY Digital Pinball Console Plays Hundreds Of Games

March 14, 2011 by Mike Nathan 23 Comments

pinball_console

Pinball machines, while likely considered pretty retro technology by most, are still a fun and engaging way to waste a little time. The problem with pinball machines is that they take up a lot of space, making the hobby of collecting them pretty prohibitive unless you have tons of spare room in your house.

[tbarklay] loves pinball machines but doesn’t have to room for an elaborate collection. Rather than purchase one machine, he opted to build his own pinball table that can be used to play any number of games. He repurposed an old PC to power his table, connecting it to a 24″ LCD panel for the main display board. A custom cabinet was built to contain the large LCD panel as well as the computer. A 19″ LCD screen was mounted on top of the cabinet to serve as the backglass display. A set of arcade buttons were also added to the console to provide realistic paddle control.

While we don’t have a video of his particular table in action, check out this video we found of a pinball machine that uses the same setup.

Continue reading “DIY Digital Pinball Console Plays Hundreds Of Games” →

CNC Etch-a-Sketch Draws On Itself

March 14, 2011 by Mike Nathan 9 Comments

cnc_etchasketch

Having never been any good with an Etch-a-Sketch, [Ben] decided it was time to tame the children’s toy that had taunted him for so long. He received one in a gift exchange a few years back and hung onto it, recently digging it out again to fit it with some CNC components.

Using his RepRap, he printed a set of mounting plates and gears to drive the Etch-a-Sketch’s dials. He installed a pair of Airpax steppers to the gears and wired them up to an ATmega AT90 USB board he had sitting around. He installed RepRap firmware on the microcontroller, since it has a built-in gcode interpreter, making it easy for him to upload any gcode file to the Etch-a-Sketch for drawing.

You can see a quick demonstration of the device in action below. He converted a spiral image to gcode, then uploaded it to the Etch-a-Sketch – the machine does the rest. It draws pretty quickly as well – [Ben] even suggests that he could probably get it moving fast enough to melt the stylus!

It would be great to see the Etch-a-Sketch configured to support an online interface. That way he could allow people to upload images to the device, later showing off the artwork in a web gallery not unlike the LOL Shield Theatre we featured last week.

[via Make]

Continue reading “CNC Etch-a-Sketch Draws On Itself” →

Domo Kun Robot Achieves Balance Sans Gyroscope

March 10, 2011 by Mike Nathan 14 Comments

Every time it tips over, the FSM kills a kitten

Most self-balancing robots use some sort of circuitry like gyroscopes or accelerometers to keep them upright. Some bots however, can achieve nearly the same effect by far less complicated means.

Meet the Domo Kun wobbly bot, created by [Chein]. The robot is essentially a pendulum, where the pivot point is even with the wheel axle. The base of the robot is loaded with batteries, motors, and weights, all of which keep the robot relatively steady while zooming about the room. A light balsa wood frame was fitted to the top of the metal chassis, and a thin cardboard Domo Kun shell was mounted on top of that. The robot is driven using the remote control circuitry that he stripped from a toy car. He also mentions that the positioning of the batteries and weights is key to getting the robot to balance and roll properly – something that took several attempts to get just right.

Now if he could only program it to autonomously chase kittens…

Be sure to check out the pair of videos we have below of the robot chassis in testing as well as the final product.

[via HackedGadgets]

Continue reading “Domo Kun Robot Achieves Balance Sans Gyroscope” →

Sound-sensitive Android Figure Speaks In Morse Code

March 10, 2011 by Mike Nathan 16 Comments

mechanized_android_figure

Instructables user [tanbata] recently got his hands on a Google Anroid figurine and thought that while it looked great, it served no real purpose. He decided to change that, and converted this once-useless hunk of plastic into a miniature robot that moves and responds to sound.

He pried of the head of the figure and got busy fitting a servo into the Android’s body to enable head movement. An ATiny was added to control the figure, along with a microphone to enable it to respond to sound. A piezo was inserted to relay Morse code messages, and a handful of LEDs were installed in the body cavity and eyes of the figure just for kicks.

When the bot is powered on and senses a loud enough sound, the eyes light, the head spins from side to side, and the robot spouts off a random message in Morse code as you can see in the video below.

It’s not the most advanced project out there, but with a few tweaks, it could make for a great USB-powered email or IM notification system for your PC. Better yet, it’s a great project to do with a child who is interested in electronics, since they get to make a cool robot toy they can keep.

Continue reading “Sound-sensitive Android Figure Speaks In Morse Code” →

Controlling Fire With Your Mind (and Your Thumb)

March 8, 2011 by Mike Szczys 6 Comments

[TechB] is using his mind to control fire. Well, what he’s really doing is using a Mindflex to control a lighter.

Many will remember the Mindflex from this shockingly awesome hack. But [TechB’s] approach follows in the footsteps of this Arduino interface for the device. He’s using the Arduino Brain Library to read data from the head-mounted EEG and sending commands to his own fire control system. Said system is composed of a cigarette lighter and a servo motor. The motor connects to the gas regulator on the lighter, opening it up when you concentrate and closing it when your mind wanders. The result is a higher flame to show more organized brain function. The only problem with the prototype is the burns you’ll get on your thumb from depressing the lighter’s valve while trying to get your thoughts in order.

Check out the video after the break to see this in action. [TechB] is looking a bit like the Borg at the beginning of the clip, making us wonder what other Mindflex hacks he’s already performed.

Continue reading “Controlling Fire With Your Mind (and Your Thumb)” →