$20 Fuel Injector Tester

January 16, 2011 by Mike Szczys 39 Comments

[Dino] is an auto mechanic and needed a way to test out fuel injectors. Commercially available tools start well over $100 and go up from there, but he built his own for about $20.

The injectors have a coil in them that needs to be tested. His design calls for a series of 0.008 millisecond pulses to test the coil. He started by setting up a 555 timer to output a one second pulse. This signal is fed into a second 555 chip that outputs the 0.008 pulses and in turn actuates a MOSFET to switch the coil on and off. To use it [Dino] connects to a 12V bench supply and to the injector, using a single button to start the test. See him explain the setup in the video after the break.

Continue reading “$20 Fuel Injector Tester” →

Binary Clock Using Logic Chips And Mains Frequency

January 16, 2011 by Mike Szczys 29 Comments

[Osgeld] built himself a binary clock. He didn’t take the time to explain his project, but he did post beautifully hand-drawn schematics and pictures of the circuit (PDF) as he was building it. We’ve seen clock projects that use mains frequency as the clock source and that’s the route that [Osgeld] chose for his build. He started with a 9-12V AC wall wort as a power input. From there it’s just a matter of using a bridge rectifier to convert to DC, then a 7805 linear regulator to establish a steady 5V rail. A resistor and a couple of diodes allow him to pull the 60 Hz frequency off of the incoming AC, and then use a combination of 4000 and 7400 logic chips to count the pulses and keep track of the time.

Quiz-o-Tron 3000

January 16, 2011 by Caleb Kraft 19 Comments

Who would have known that being given the task of planning a holiday party at a wine bar would turn into a hacking project? Well, here’s how that happened. A committee was in charge of the festivities and had decided on doing a mock game show. It wouldn’t really feel like a game show unless you had a contestant lockout system where the first one to hit the button gets a light and a sound while the runners-up get nothing. This is where [RoysterBot] comes in. He built the Quiz-o-Tron from 4 “easy buttons” from staples and an Arduino. After having finished it, he found the system to be somewhat lacking in the excitement area. When a button was pressed it only lit an indicator on the main Quiz-o-Tron box. He decided to add a small circuit inside each of the Easy Buttons using a 555 timer and some LEDs to give them some better feedback. Apparently he was going to patch into the speaker as well, but didn’t have time to get that added.

[via Adafruit]

Improving A Hexapod Design

January 15, 2011 by Mike Szczys 7 Comments

[JC] built himself a hexapod based on a project he found on the Internet. It worked fairly well, but was mechanically weak and prone to breakage. He set out to improve the design and came up with the unit seen above. It uses three servo motors to control the six legs, and walks quite well as seen in the quick clip after the break. It’s not quite as agile as the little acrobatic six-legger we saw yesterday, but the movement is quite pleasing and it’s capable of moving forward, backward, and turning. [JC’s] post is four pages in all so don’t forget to seek out his links for the construction, linkage, and servo control pages to find concept drawings, cad designs, and his thoughts on the process.

Continue reading “Improving A Hexapod Design” →

Two Generations Of Ocean-going ROV

January 15, 2011 by Mike Szczys 19 Comments

[Eirik] wants to help inspire others to take on big projects to he sent in a link to his ROV project. He started it about one year ago and the image above shows the first generation. After the break you can see the video that the ROV captured during a couple of it’s initial voyages. They’re pretty clear and right off the bat you’ll see the little guy following a jellyfish. Like a lot of homebrew ROV’s [Eirik] is still searching for the right way to pass wires through the housing without leaks. He does okay so far, and has designed a nice cable spool for the topside tether, but some water does get in. He’s almost finished the second generation which re-designs the camera mount to aim downward so that what’s in frame is more interesting.

Continue reading “Two Generations Of Ocean-going ROV” →

Converting 8mm Film To Digital

January 15, 2011 by Caleb Kraft 24 Comments

Many of us have these old 8mm family videos lying around and many of us have lamented at the perspective cost to get them converted to digital. [Paul] came up with a pretty slick way of digitizing them himself. He cracked open an 8mm projector and replaced the drive motor with one he could run at a much slower speed, allowing him to be able to capture each frame individually with his digital camera. He’s rigged his remote shutter control to the shutter of the projector so that it would be perfectly synchronized. There’s a video of it in action on the flickr page, and a video of the full 16,000 frame clip after digitization here.

[via Make]

R2D2 Wannabe Lacks Lightsaber Launcher, Autonomy

January 15, 2011 by Mike Szczys 14 Comments

Is this what the lovable Star Wars droid would look like without its protective skin? This R2D2 inspired robot is another Olin College of Engineering (where that CNC cake decorator came from) build developed by [Nathaniel Ting] and his classmates. Alas, it lacks autonomy, relying on an operator for guidance. But we enjoy it for the build quality. Two motorcycle batteries supply DC motors on the two rear legs of the trike. It can be driven with a wireless Xbox controller or through a Python interface that also randomly plays droid audio clips from the movie. That’s a tilting projector on top, which would be used to show Princess Leia’s pleas for assistance. That is, after the operator plugs in an extension cord to power it up. Oh well, it’s still a lot of fun to watch. See for yourself after the break.

Continue reading “R2D2 Wannabe Lacks Lightsaber Launcher, Autonomy” →