Cheap Toy Yields Good Parts

December 19, 2009 by Mike Szczys 25 Comments

We’ve spent some serious time building robot chassis and motor controllers. [Whamodyne] does the smart thing and scavenges what he needs form cheap sources. He picked up an RC car from the local pharmacy for just $10, tore the body off and behold, a bounty of robot-friendly parts.

We’re not talking precision parts here, but we don’t scoff at two geared motors, four wheels, a driver board, and steering. There’s no great way to attach your own stuff but that’s half the fun of hacking. [Whamodyne] used the 9v battery that came with the toy to power his boarduino and quickly patched in to produce a miracle of automated locomotion.

Movie Mover: A Mobile Theater

December 4, 2009 by Caleb Kraft 18 Comments

[youtube=http://www.youtube.com/watch?v=po8F6lIFhkk]

[Electricunicycle] put together this radio controlled mobile theater system to amuse his neighborhood pals. It is a projector and what looks like an electric wheelchair base. He has managed to fit a decent sound system in there as well, which required a second battery. This is pretty cool, though we could see ruggedizing it a little more to be able to drive around in fields. He states “this is one of the faster movie theaters around”. This makes us wonder what the competition is like.

Phone Controlled Solar Charged Tank

December 3, 2009 by Caleb Kraft 11 Comments

[youtube=http://www.youtube.com/watch?v=RmLU4GS7zAI]

This looks like a fun little project. [Chris] has built a tank that he is controlling using his iPhone. Constructed mainly of off the shelf parts, like an Arduino and an Xbee wireless unit, the tank is controlled via processing. You can see that it is fairly responsive as he changes the speed of the motors. You don’t need an iPhone for this, really to do exactly what he’s doing any multi-touch input would work. You can download the code for it from his site.

We’re a bit curious about the solar charging. How much power does this use? Doesn’t that panel look a bit small? How long does it take to charge?

[via HacknMod]

R/C Airplane Motors From Computer Trash

November 17, 2009 by Caleb Kraft 18 Comments

Here’s something that the R/C airplane crowd might think of as old news. These directions show us how to rework floppy drive and CD Rom motors to be high power airplane motors. There are several listed, with details on each, but those unfamiliar might want to start with the most basic CD Rom version. It covers winding your own copper and installing the magnets in the “bell”, putting it all together and mounting it. This is a great writeup for those who haven’t seen this done before. If you want something even simpler though, you might enjoy the homopolar motor post. If you’re more advanced, they have tips for you too on machining and balancing the motors as well as winding density.

Radio Assisted Drawing Device

November 16, 2009 by Mike Szczys 7 Comments

radio-assisted-drawing-device

An exhibition just wrapping up at the Russian Frost Farmers Gallery in New Zealand presented an interactive artwork hack. Called the Radio Assisted Drawing Device (R.A.D.D), it is a plotter that mounts on the wall. It isn’t computer controlled, but rather relies on a remote control with two sticks to move the plotter Etch-a-Sketch style.

A clear gantry mounts vertically and travels along the top edge of the wooden backing. A slot cut in the acrylic steadies the plotter and allows for smooth vertical movement. Obviously built by hand, the mechanics seem to have tight tolerances for precise movements of the stylus. See the exhibit in the video after the break.

Wouldn’t you love to have one of these on the wall at your next party? It adds a whole new spin on a guest book.

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R/C Lawnmower

November 14, 2009 by Caleb Kraft 56 Comments

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[Johndavid400] built this incredible looking R/C lawnmower. After spending some time repairing broken R/C cars, he wanted to move on to something a little more useful and powerful. He decided to build a mower. He’s using a transceiver set from ebay, with an Arduino interpreting the signal and outputting to his custom motor board. In the video after the break, you can see that the mower looks responsive and quick. He does note, however, that he had some glitches early in the process that left him with a runaway mower. We covered a very similar mower ages ago that used a wheelchair as the base.

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Battery Capacity Tester

November 11, 2009 by Mike Szczys 16 Comments

battery-capacity-tester

[Moris_zen] built a device to accurately measure the capacity of batteries. He needed to have an accurate measurement for the batteries he uses in a RC airplane. Knowing the discharge time allows him to fly the friendly skies while avoiding crashes from lost communications.

He based the tester around the Arduino platform. Instead of using a pre-built Arduino board he referenced the open source schematics and built the device from components to fit his needs. His solution automatically detects the battery type (Lithium-Ion, Nickel Metal Hydride, etc) based on voltage when the battery is added to the circuit. It then uses a 2.2 Ohm resistor and ADC measurements to take the battery through a discharge cycle. A character display shows status information with the ability to track discharge information using a computer to graph the data.

Apart from flashing an LED this was his first Arduino project. It’s a great use of the platform and much more automatic than other solutions we’ve covered.