Electric tricycle build log is like hacker crack

April 5, 2013 By 24 Comments

electric-tricycle-burns-rubber

This tiny little scratch-built electric tricycle is a insanely powerful. Some might think you don’t need a crash helmet for testing a trike, but seeing the video after the break where [Ben Katz] is flying through a parking garage while slaloming between the support beams proves that this ride has some pep to it.

Looking through the presentation post linked above is fun, but when we started digging though the six build log posts we felt ourselves getting sucked into the project. It’s a delight every step of the way. It started with an aluminum box which will host the two rear wheels, drive train, motor, and battery. [Ben] decided to go with A123 Lithium cells, and after testing to see how many he could fit in the space available he started making choices on the motor and driver circuit. When he finally got his hands on the actual cells for the project he took on the fascinating process of constructing his own battery. Dozens of them were hot glued, then soldered together before being encased by placing them in soda bottles and hitting the plastic with a heat gun. And we haven’t even gotten into the bicycle hub-gear transmission system, disc brakes, differential, chain-drive, and motor… you see what we mean about sucking you in.

Oh, and in case you’re wondering this is not [Ben's] first electric vehicle build. Last year he was showing off his all terrain scooter.

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Filed Under: High Voltage Hacks, transportation hacks Tagged With: , , , , ,

Snowboard goggle HUD displays critical data while falling down a mountain

April 5, 2013 By 17 Comments

snowboard-google-hud

[Chris] has been hard at work building a Heads Up Display into some Snowboarding goggles. We’re used to seeing the components that went into the project, but the application is unexpected. His own warning that the display is too close to your face and could cause injury if you were to fall highlights the impractical nature of the build. But hey, you’ve got to start somewhere when it comes to prototyping. Perhaps the next iteration will be something safe to use.

A set of MyVu glasses were added to the top portion of the goggles, which lets the wearer view the LCD output by looking slightly up. The display is fed by a Raspberry Pi board which connects to a GPS module, all of which is powered by a USB backup battery. In the video after the break you can see that the display shows time of day, speed, altitude, and temperature (although he hasn’t got a temperature sensor hooked up just yet). His bill of materials puts the project cost at about £160 which is just less that $250.

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Filed Under: wearable hacks Tagged With: , , , , , , ,

Home security hardware makes you the monitoring service

April 4, 2013 By 16 Comments

diy-home-security

[Nick] and [Simon] both have home security systems with a monitoring service who will call whenever an alarm is tripped. For [Simon] this ends up happening a lot and he wanted to change the circumstances that would trigger a call. Because of company policy the service is inflexible, so he and [Nick] went to work cutting them out of the loop. What they came up with is this custom electronics board which monitors the security system and calls or texts them accordingly.

They started with the self-monitoring alarm system design we looked at back in September. This led to the inclusion of the SIM900 GSM modem, which is a really cheap way to get your device connected to the cellular network. It also uses a DTMF touch tone decoder to emulate the phone line to keep the security system happy. [Simon] highlights several changes he made to the design, as well as the reasons for them. One idea he has for a possible revision is to do away with the MT8870 chip which handles the touch tones. He thinks it may be possible to use the SIM900′s DTMF features to do that work instead.

Filed Under: arduino hacks, home hacks, security hacks Tagged With: , , , ,

High speed circuit design for quantum physics light sensing

April 4, 2013 By 17 Comments

high-speed-sensor-sampling

[Limpkin] designs circuits for a living. This board is one of his recent projects, and although his skills are light years ahead of our own experiences, he did a pretty good job of explaining how he put this board together.

He was tasked with measuring the light intensity of two photodiodes. The expected impulses picked up by those components will be less than a nanosecond in duration, putting some special design constraints upon him. To register this signal he’s using three cascading op-amps per input. To ward off false readings from RF interference he also designed in the shielding which you see surrounding the majority of the circuit.

His package choice for the THS3202 op-amps is quite interesting. He didn’t go with the footprint that includes a thermal pad to dissipate heat because he didn’t want to interrupt the ground plane on the underside of the board. To keep the parts from melting he added an aluminum spacer that contacts the top of the package, then a heat sink that covers the entire shield frame. In a future revision he figures he’ll move to a four-layer board so that the can opt for the MSOP package that does the work for him.

Filed Under: misc hacks Tagged With: , ,

Steampunk theremin goggles

April 4, 2013 By 10 Comments

wearable-theremin-goggles

Lots of people build custom steampunk goggles, but most don’t implement any interactivity – they’re just an aesthetic accessory. [Sarah] recently decided to built a pair that, besides looking cool, would engage the wearer in creating sound. She accomplished this by integrating an optical theremin into their design.

To keep the build both affordable and wearable she researched simplified theremins, and eventually settled on creating a basic model that uses only a handful of components and two 555 timers. The main body of the goggles was constructed using mostly random mismatched pieces of metal and leather.  Mounted on the outer edge of each lens, there is a photo sensor and a corresponding slider control. Adjusting the slider alters the level of resistance, therein changing the pitch of the sound. The theremin will produce different pitches and octaves depending on how much light the sensors receive. So, the wearer, or a nearby friend, waves their hands around the wearers head to control it.

The speaker and volume knob are cleverly disguised as the two ‘lenses’. Rotating the volume knob lens adjusts an internal potentiometer that’s held in place by a custom laser etched piece of acrylic. To top it all off, she even designed her own PCB using Eagle.

Check out a video demonstration after the break.

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Filed Under: musical hacks Tagged With: , , ,

Top 10 Hacking Failures in movies: part 2

April 4, 2013 By 81 Comments

After going through the original quick list we tossed together, people were chiming in like crazy. We felt another 10 might help satiate the desire to smirk at the silliness of tech portrayed in movies and TV. Gathering examples from your comments, we have compiled part 2.  While I would have loved to narrow this down to a specific item like incorrect lingo or screen grabs, I didn’t quite have enough specific scenes to do it yet.  Be sure to keep the comments coming and be specific, I haven’t seen many of these till someone points it out.

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Filed Under: Ask Hackaday, rants Tagged With: ,

Melting Metal with a DIY Foundry Furnace

April 4, 2013 By 33 Comments

Foundry Furnace

If you want to do casting at home, you’ll need a way to melt metal. [Jake]‘s DIY foundry furnace gets hot enough to melt aluminium, and is built out a mix of scrap parts.

The chamber of the furnace is built out of a water heater tank which has been lined with a special cement that refracts heat. The furnace is heated by a Babington burner. This type of burner works by atomizing the fuel and injecting it into the furnace. They are good for burning waste oil to achieve high heats.

A scrap Volkswagen oil pump and a cordless drill are used to feed oil into the burner. Once it’s fired up, the furnace takes about 10 minutes to melt the 11 pounds of metal that it can hold. [Jake] melted about 40 pounds of aluminium alloy from scrap alloy wheels in 2 hours, which should be more than enough for a home casting project.

After the break, check out the overview of the device and a demo of melting aluminium.

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Filed Under: tool hacks Tagged With: , , ,
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