Another take on using ‘dead’ batteries

Here’s another circuit that can be used to squeeze the remaining potential from supposedly dead batteries. Just like the AASaver, we see this as a useful prototyping tool, providing juice for a breadboard even though it’s not reliable enough for long-term use (the batteries are just about through after all).

First off, the image above shows rechargeables instead of alkalines. We don’t recommend this as the circuit has no cutoff feature and the 0.7V input for the boost converter surely is below the recommended low-voltage limit for those cells. But that aside, we like the diminutive board which solders onto the end of a battery pack. It uses an SC120SKTRT which is a variable boost regulator capable of outputting 1.8-5V depending on resistor choices. You can leave the resistors off and it will default to 3.3V, set the output explicitly, or roll in some potentiometers and use your multimeter to tune the output.

This regulator costs more than the MCP1640 used in the AASaver, but it appears to use less passive components making for a smaller footprint. At a total of $3.50 plus the PCB (which will be a snap to etch at home) this is another great option to top off your next parts order.

[Thanks Uwe]

New extruder 3D prints tasty treats using chocolate

If you’ve never felt at home with a piping bag in your hands this chocolate extruder will come to your rescue. It can replace the plastic extruder head on your 3D printer (RepRap, Makerbot, most 3-axis CNC machines, etc.), letting you turn your digital creations into decadent reality.

The head uses a progressive cavity pump to feed the chocolate from a reservoir through the printing nozzle. It’s important to keep the chocolate warm or it will set up so when [Tomi Salo] designed the print head he included a heat shroud through which warm air can be circulated. He uses a shoe dryer to source the hot hair which is patched into the heat shroud with a length of tubing.

This extruder can be 3D printed but be careful what material you use. [Tomi] mentions that PLA is ‘sort of food-safe’ but ABS is not. We wonder if the design could be altered for milling out of aluminum or stainless? At any rate, if you’re going to give it a try you might find [Tomi's] advice on working with chocolate useful.

[via @clothbot]

Python PIC useful when attached to a computer

[Richard] sent in a link to the Python controlled microcontroller he’s been working on. Unlike the previous portable Python boards we’ve seen, [Richard] thinks his pyMCU isn’t best used autonomously. This board is meant to be used only when connected to a computer and to serve as a bridge between the digital world of computers and our analog world.

We’ve seen boards running lightweight Python interpreters, but we’re fairly intrigued by the idea of this board only being useful when plugged into a computer. The on-board PIC 16F chip has enough digital, analog and PWM pins to just about any task imaginable, and there’s also a 16-pin LCD display header if you’d like some output with your microcontrollers.

[Richard] says he’s been working with PICs for longer than the Arduino is around, but depending on the level of interest he’ll consider developing an Arduino version of the pyMCU. All we know is that the pyMCU would be awesome to teach electronics and programming to the younglings, and we could certainly find a few more uses for the board when they’re done with it.

Human-shaped planes troll NYC

It looks like a genetic leap has unleashed the age of mutants, but this is really just a few guys trolling New York City with some custom RC aircrafts. The video after the break shows the fliers up close. They’re pretty much full size, we’d guess 5’10” from head to heel. The outstretched arms and body act as wings, while the legs act as ailerons and rudders. But from afar (or even a medium distance) it’s quite difficult to make out the flat surfaces… they look like office workers loosed from their cubicles. Unfortunately we don’t have more than a flight demo to share with you. If you know where to find build info (or any extra details at all actually) don’t forget to send in a tip We wonder if these are the same guy who made the flying hero we posted back in July?

There’s another nugget of delight right at the beginning of the video. A sweet octocopter which looks much like this one was used to capture the aerial footage.

[Read more...]

$15 toy becomes fully programmable robot

[Kevin] undertook a robot build partly for his own enjoyment, but also to include his kids in the action. He acquired a cheap toy and packed it full of programmable goodness. The starting point was a $15 toy called Rad 2.0. It’s a great starting point as it already included some motorized parts, and takes care of much of the mechanical issues like joints and structure.

The image on the left is the fourth update which [Kevin] has posted. The robot now responds to voice commands (with the same syntax as Chippu uses), moving its gaze to face forward or to either side. You’ll notice there’s a wireless webcam which lets him spy on what’s in front of the robot’s gaze. An ultrasonic range finder makes itself at home in the beak of the bot, and a Larson Scanner is nestled in the brow using the kit from Evil Mad Scientist Labs. Check out the video after the break for an overview of the hardware modifications.

The build log for this project is a forum post. That forum is run by [DJ Sures], a veteran at taking cheap toys and making them awesome. It seems like he’s taken a web forum and made it awesome too because the conversation about [Kevin's] project is packed with constructive tips and encouragement.

[Read more...]

Building a flex sensor from component packing materials

Hacks like this one don’t help us recover from extreme pack-rat behavior. Driving home the point that one should never throw anything away [Peter] built a flex sensor from component packing material. It uses the black conductive foam in which integrated circuits are sometimes embedded for shipping. Above you can see the grey rectangle which is the sensor itself. in the background of the image, each component used in the build is labelled except for the tape.

The project starts with the foam being cut to the appropriate size and thickness. He does the same with some aluminum foil, then rips tape strips to act as the enclosure. Fine wire from some cable shielding serves as the two conductors for the sensor. He attaches each wire to an upturned piece of tape, followed by the foil, and finally the foam. When the two halves are assembled in the video after the break, [Peter] hooks up his multimeter to show the change in resistance as the sensor is bent.

We think it will take a clever calibration algorithm to get this working reliably, but it’s no more troublesome than the optical flex sensors we saw in this links post. [Read more...]

Motorcycle engine hack like having an old F1 between your legs

The difficulty of rolling a 16-cylinder engine into a motorcycle really boggles the mind. But that’s exactly what [Andreas Georgeades] is doing in his garage. It’s two straight-8 engines sandwiched on top of one another with a custom crankcase connecting them. And get this, those custom parts are being milled by hand, using time-tested techniques rather than modern computer assistance.

So, where does the complexity come in? Well first of all you’ve got to solve all of the problems that go along with combining two engines. It sounds like this isn’t a new concept, as older generations of Formula 1 engines used the technique. But we still think it’s the pinnacle of hardcore when it’s an enthusiast undertaking the challenge. Then there’s the issue of weight. The engine is bulky, but needs to balance in the frame. And you still must find a way for the rider to sit on the thing (even the most bow-legged of people won’t be able to get their hips around the thing).

Seems like something out of a Mario Kart game that should have no chance of being roadworthy. But we’re sure [Andreas] is going to prove us wrong.

[Thanks Th3BadWolf]

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