Rotating platform makes most useless machine concept useful

[Valentin] used a simple concept to build this auto-reversing rotating platform. The concept is extremely simple, the leads for the motor are attached to a double-pole double-throw switch which allow the polarity to be reversed. Flip the switch in one direction and it spins clockwise. Flip it in the other direction and it spins counter-clockwise.

In this case, he’s harnesses the power of the most useless machine. That often seen hack uses a similar switch, but accomplishes nothing by having the moving parts act as the actuator. This one is useful, taking advantage of a single or double arm to flip the switch and make the platform spin backwards. In the video after the break you can see it’s used to create a scanning security camera. But [Valentin] also shows it at work as a turntable for salable goods. We think’s the gearing is a little brisk for both purposes, but slowing it down is a hack for another day. [Read more…]

A TV-B-Gone with a PIC twist

pic-tvbgone

[Kayvon] thought that the TV-B-Gone was a fun little device and wanted to build one, but he didn’t have an AVR programmer handy. Rather than picking up some AVR kit and simply building a replica, he decided to give his PIC skills a workout and build a Microchip derivative of his own.

The PIC-based TV-B-Gone is pretty similar to its AVR-borne brethren, featuring a PIC24F08KA101 at the helm instead of an ATTiny. His version of the TV-B-Gone can be left on indefinitely, allowing him to situate the device in a convenient hiding place to wreak havoc for as long as he likes.

[Kayvon’s] TV-B-Gone does everything the original can at just under $7, which is quite a bit cheaper than the Adafruit kit. If you’re not averse to perfboard construction, be sure to check out the build thread over in the Adafruit forums. [Kayvon] has done most of the heavy lifting for you – all you need to do is build it.

Worried about Haloween this Year? Why not a Giant T-Rex Costume?

Although some might note that [Jamie]’s creation could mistaken for a Velociraptor or even Allosaurus, his giant T-Rex costume/model is quite a feat of artistry. It stands at over 14 feet tall and 10 feet long. For comparison, the room that you see in the picture above measures 25 x 25 feet. If you happen to live in the Atlanta area, or are willing to travel, this costume is expected to make an appearance at Dragon*Con in 2012, so be sure to look for it there.

The whole thing is made from poly foam plank cut with a CNC router.  It also has a metallic support structure. As noted in the article, you could, in theory, cut all these parts out by hand. Persistence would be required though, since there are over 140 parts!

[Jamie]’s making capabilities are obviously quite advanced at this point, but he’s trying to expand them by winning a router in the Instructables Shopbot contest. If you like his creation, be sure to vote for him! Check out the video of this costume in action after the break. [Read more…]

Data broacasting "Transparency Grenade" ads whimsy to your meetings

If you’re tired of underhanded deals going down behind closed doors maybe you need to start carrying around this transparency grenade. The enclosure is modeled after a Soviet-era F1 Hand Grenade. But it’s not filled with explosives and won’t send deadly shrapnel around the room. Instead, when the pin is pulled it starts recording audio and sniffing network packets, then broadcasts both to a remote server. Perhaps you could consider this to be data shrapnel sent around the world.

The exploded parts image above shows what hardware is at use. There’s a Gumstix board at the heart of the device which uses a WiFi module for sniffing and broadcasting data. The LED bar graph which you see in the fully assembled unit shows the wireless signal strength.

It sounds like the enclosure itself was 3D printed from Tusk2700T translucent resin but we’re a little confused by this part of the hardware description. We don’t have much of a need to transmit recordings of our meetings, but we’d love to use this case design for that MP3 enclosure.

[via Reddit]

Wedding gift fail has happy couple cursing your name

[Superluminal] received an invite to his friend’s wedding. He got together with some mutual acquaintances to take up a collection as a wedding gift. But as things go, a suitable present couldn’t be found. The pooled money itself ended up being the gift, but apparently a greeting card with a money pocket inside of it wasn’t good enough. The group decided to encase the coinage in a block of sugar that doubles as a lamp.

Now as with many well-meaning projects this started out with a rendering of what the final product would look like. That image came out great, with a high-gloss dark amber cube lit from the bottom with the coins suspended throughout catching a bit of a glint. They bought 43kg (almost 100 pounds) of refined sugar, and made a base/mold combination out of sheet metal. A lot of induction cooking went into producing thick syrup that could be poured into the mold. The problem is the final product is basically opaque. Not a sign of the 300 Euros within.

But don’t feel too bad for the groom and his bride. The image above shows him trying to get at the prize. He must do some hacking himself because he has a pressure washer, jack hammer (or is that big drill?), humongous cold chisel, and sizable hatch already at his disposal.

We can’t help but wonder if a heat gun could have polished the sides of the cube and helped add translucence?

Intro to Phase-Locked Loops

[Kenneth Finnegan] put up a lengthy primer on PLLs (Phase-Locked Loops). We really enjoyed his presentation (even the part where he panders to Rigol for a free scope… sign us up for one of those too). The concepts behind a PLL are not hard to understand, and [Kenneth] managed to come up with a handful of different demonstrations that really help to drive each point home.

A PLL is made up of three parts: a phase detector, a low pass filter, and a voltage controlled oscillator. It can do really neat things, like multiply clock speed (you see them in beefier chips like the ARM architecture all the time). The experiments seen in the video use a CD4046 chip which has two different types of phase detectors. The two signals displayed on the oscilloscope above compare the incoming clock signal with the output from the VCO. Depending on the type of phase detector used, and the quality of the low-pass filter, these might be tightly synchronized or wildly unstable. Find out why by watching the video embedded after the break.

[Read more…]