Entrust You Kid’s Life To A Homemade Roller Coaster?

February 26, 2011 by Mike Szczys 49 Comments

So you fancy yourself as an amateur engineer? Been working on those welding skills for a while? The real test is to trust your children’s lives on a roller coaster you’ve designed and built (translated).

Now we’re not talking some tired old carnival ride like the teacups. This is a full-blown roller coaster, complete with an upside-down loop. The ride starts off with a chain-lift to the top of the garage/barn roof. From there it’s off and away on the single-rider train. We’d recommend keeping your hands and feet inside the car… if there was a car. The ride utilizes an automobile seat, but you’ll have to settle for a lap-belt as there’s no shoulder restraint here. We’re a bit wary of the track footings – we’d bet they’re not well anchored in the ground – but the fact that the entire length of track has been painted makes us think that [John Ivers] might have known at least a little bit about what he was doing. Don’t forget to catch the video below the fold.

Update: Much better video now embedded after the break thanks to [Tom 101’s] link in the comments.

Update: Source link changes to the original thanks to [Mike’s] comment.

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Image Projector Can Be Built In Minutes

February 25, 2011 by Mike Szczys 14 Comments

There’s a pretty good chance that you already have everything needed to make this image projector. We thought that yesterday’s video projector was simple, but this one makes it look like a super-computer in comparison. [Esrun] grabbed a flood light, some transparency film, and a common magnifying glass for use in his still-image project. This is more-or-less an overhead projector without the mirror, but we though it was worth sharing in hopes that it would spark your imagination and produce some other projector-oriented hacks.

The real tricks in this build are alignment and focal length. A single piece of lumber was used to help keep everything in a straight line, leaving just the vertical alignment to account for. In order to get the image in focus, [Esrun] had to do some testing for positioning the transparency film and the lens. In the end he added strips of velcro to the base to make the components easy to move. He plans to add an enclosure and change from an incandescent bulb over to a set of LEDs. We’d like to see the addition of a carousel that can house multiple transparency sheets. That or a side-scrolling roll to give it more of a film-strip feel.

Gauss Weapons

February 23, 2011 by Mike Szczys 34 Comments

This collection of gauss weapons use rare earth magnets to accelerate projectiles to damaging speeds. They work using the same concepts as a coil gun, but instead of just one projectile travelling along a length of guide track, there are many projectiles that work in a chain reaction. A series of magnets are placed at equal distances along the track. Each has a couple of large ball bearings on the muzzle side of the magnet. The first ball bearing is fired using mechanical force – like a spring mechanism – and accelerates as it approaches the magnet due to the attractive force of that magnetic field. When it impacts the magnet it sends one of the ball bearings on the opposite side down the track where it will accelerate when it nears the next magnet in the chain. The weapon above achieves a final projectile speed of about 68 miles per hour, breaking six fluorescent tubes in a row on at the right side of the apparatus.

Still prefer rail guns that use electromagnets? Check out this gauss pistol kit that is about as powerful as a BB gun.

DIY Fizzy Fruit

February 17, 2011 by Mike Nathan 37 Comments

co2inator

[Rich] over at Evil Mad Scientist Labs took it upon himself to make eating fruit a little more enjoyable for his kids by infusing it with CO2 using his CO2inator. Observing the same principles used in making soft drinks and force-carbed beer, he decided to build a CO2 pressure chamber for use in his kitchen. He gathered a handful of easy to find components to construct his rig, including a household water filter housing and a CO2 cylinder from a paintball gun. He has some helpful hints for those who are not familiar with the process, noting that refrigerated fruit absorbs the gas more quickly than warm, and that considering the water content of the fruit is important when selecting what to carbonate.

Once [Rich] had everything safely connected and checked for leaks, in went the fruit. After about half an hour to an hour, the fruit was carbonated, much to the delight of his children. This looks like a quick and fun project for adults and kids alike, that can easily fit into a busy weekend schedule.

[via Neatorama]

Screamer Doll Prank Toy

February 15, 2011 by Mike Nathan 10 Comments

screamer_doll

While it is only the middle of February, it might be a good time to start thinking about your plans for April Fool’s day. [Dino’s] Screamer Doll is his submission to the upcoming 555 Contest. This fun little circuit can be used to easily annoy your cube or house mates and is perfect for all of the April Fool’s day pranksters out there. He fit all the components into a small plastic toy, replacing the eyes and mouth of the doll with three photo cells, and swapping the nose out for a bright LED. When light hits the photo cells, a loud high-pitched squeal is emitted, and the LED blinks furiously until the light source is removed. Shielding the device from light will cause both the sound and LED to slow down, but the brightness of the LED ensures that the toy still makes noise when covered.

It would be great to see a version of this project that is completely silent in the dark, allowing it to be hidden at night, greeting its victims come morning.

If you want to see video of the device in action, read on – just be sure to keep your speaker volume at a reasonable level!

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Pactuator: Mechanical Pac-Man Frame

February 14, 2011 by James Munns 16 Comments

As a proof of concept for his long term work in progress “The Pac-Machina” (an electro-mechanical reimagining of a Pac-Man cabinet), [Jonathan] needed some way to make a mechanical Pac-Man, flappy jaw and all. After working through a couple different design possibilities, he decided on an interesting setup which includes using a cog with only half its teeth to make the mouth open and close. Unfortunately, NAMCO BANDAI has asked him nicely not to sell these as kits, but he has helpfully included just about all that is required to make one of these from scratch. [Jonathan] even cut and laser etched his own faux-Victorian frame to keep his proof of concept Pac-Man ready until needed for the main project.

Nixie Tube Thermometer

February 14, 2011 by Mike Nathan 17 Comments

nixie_therm

After seeing a picture of a thermometer using a bargraph style nixie tube in place of a mercury column, [Juergen Grau] decided he wanted to build his own. Dubbed the “Nixietherm”, his replica looks even better than the original. He used an IN-9 Nixie tube mounted on top of a custom plastic case, all powered by a 5v USB connection. He points out that his version does not use a PIC or any other sort of processor – it is built entirely from analog circuits. There are some RGB LEDs embedded in the plastic case that make for a cool effect, but they seem to simply cycle through the colors rather than represent how warm or cold the temperature is at any given time.

[Juergen] does not give a lot of details regarding the build as far as PCB layout or a parts list is concernred, but most of that can be extrapolated from the wiring schematic he provided. He also mentions that he will be making kits available in the near future. Be sure to keep reading to see the thermometer in action.

Thanks [Brian]

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