Neopixels Light The Way In Pressure-Sensitive Floor

November 7, 2016 by Dan Maloney 8 Comments

It’s got a little “Saturday Night Fever” vibe to it, but this pressure-sensitive LED floor was made for gaming, not for dancing.

Either way, [creed_bratton_]’s build looks pretty good. The floor is a 5×6 grid of thick HDPE cutting boards raised up on a 2×4 lumber frame. Each cell has a Neopixel ring and a single force-sensitive resistor to detect pressure on the pad. Two 16-channel multiplexers were needed to consolidate the inputs for the Arduino that’s running the show, and a whole bunch of wall warts power everything. The video below shows a little of the build and a look under the tiles. It’s not clear exactly what game this floor is for, but you can easily imagine a maze or some other puzzle that needs to be solved with footsteps.

Light-up floors are nothing new here, what with this swimming pool dance floor. But this interactive dance floor comes close to the gaming aspect of [creed_bratton_]’s build.

Continue reading “Neopixels Light The Way In Pressure-Sensitive Floor” →

A Car Stand Made Of Sand

November 7, 2016 by Manuel Rodriguez-Achach 19 Comments

When the guys at [Practical Engineering] say they have a dirty car stand, they really mean it! They made a block of dirt and sheets of fiberglass as reinforcement material, and the resistance was put to test by using it as a car stand. And yes, the block does the job without collapsing.

An exmple of MSE — A MSE structure. The lateral walls add no strength, they just look nice.

Soil is a naturally unstable material, it relies only on friction for structural stability, but it has a very low shear strength (the resistance of the material’s internal structure to slide against itself). Therefore, as soon as you put some weight, a soil structure fails. The trick is to form a composite by adding layers of a stiff material. Those layers increase the shear strength and you end up with an incredibly strong composite, or ‘mechanically stabilized earth‘ (MSE). You probably drive by some everyday, as in the picture at the right.

Even though the modern form of MSE was due to French engineer Sir Henri Vidal, reinforced soil has been used since the beginnings of human history, in fact, some sections of the Great Wall of China were made using this technique. [Practical Engineering] explanation and demonstration video is very well made, be sure to check it after the break. In case you don’t want to play with dirt next time you need to fix your car, you can always make a 3D printed jack.

Tony The Pinball Wizard 3D Prints Full Sized Pinball Machine

November 6, 2016 by Gerrit Coetzee 11 Comments

[Tony] has designed and 3D printed a full-sized pinball machine and it’s absolutely incredible. And by 3D-printed, we mean 3D-printed! Even the spring for the plunger printed plastic.

The bumper design is particularly interesting. The magic happens with two rings of conductive filament. the bottom one is stationary while the top one is a multi material print with a flexible filament. When the ball runs into the bumper the top filament flexes and the lower rings contact. Awesome. Who wants to copy this over to a joystick or bump sensor for a robot first? Send us a tip!

The whole document can be read as a primer on pinball design. [Tony] starts by describing the history of pinball from the French courts to the modern day. He then works up from the play styles, rules, and common elements to the rationale for his design. It’s fascinating.

Then his guide gets to the technical details. The whole machine was designed in OpenSCAD. It took over 8.5 km of eighty different filaments fed through 1200+ hours of 3D printing time (not including failed prints) to complete. The electronics were hand laid out in a notebook, based around custom boards, parts, and two Arduinos that handle all the solenoids, scoring, and actuators. The theme is based around a favorite bowling alley and other landmarks.

It’s a labor of love for sure, and an inspiring build. You can catch a video of it in operation after the break.

Slow Dance Appears To Make Time Run In Slow Motion

November 5, 2016 by James Hobson 27 Comments

Rendering something in slow-motion is an often-used technique that attempts to add some ‘wow’ or ‘cool’ factor. Seeing something out in the world move in slow motion is marginally rarer — rarer still if it’s in your own home. But do it right and that kind of novelty turns a lot of heads. Enough to go 8x on a Kickstarter goal.

Slow Dance, a picture frame ringed with strobe lights, generates the surreal effect of turning small, everyday objects into languid kinetic sculptures. It’s an intriguing example of kinetic art done in a novel way.

[Jeff Lieberman], a veteran of high-speed photography, takes advantage of ‘persistence of vision’ by synchronizing the vibrations of an object — say, a feather — with a strobe light blinking 80 times per second. An electromagnet inside the frame is used to vibrate the objects, while the strobe lights are housed inside the thick frame.

Continue reading “Slow Dance Appears To Make Time Run In Slow Motion” →

Ultra Simple Magnetic Levitator

November 5, 2016 by Manuel Rodriguez-Achach 25 Comments

Want to build a magnetic levitator in under two hours? With a total of 7 parts, including the coil, it just cannot get simpler than what [How-ToDo] shows here! It is not only an extremely simple circuit, it also has the advantage of using only discrete components: a MOSFET, hall effect sensor, diode and two resistors, that’s it.

The circuit works by sensing the position of the levitating magnet, using the hall effect sensor , then turns the coil on and off in response via the MOSFET. The magnet moves upwards when the coil is energized and falls down when it is not. This adjustment is made hundreds of times a second, and the result is that the magnets stays floating in mid air.

This is the kind of project that can make a kid get interested in science: it combines easy construction with visually amazing behavior, and can teach you basic concepts (electromagnetism and basic electronics in this case). Excellent for a school project.

For the more advanced enthusiast, a more sophisticated levitator design based on an Atmega8 micro-controller will be of interest.

Continue reading “Ultra Simple Magnetic Levitator” →

Add Data To Your Shipping Suspicions With This Power-Sipping Datalogger

November 4, 2016 by Gerrit Coetzee 43 Comments

One only has to ship one or two things via a container, receiving them strangely damaged on the other end, before you start to wonder about your shipper. Did they open this box and sort of stomp around a bit? Did I perhaps accidentally contract a submarine instead of a boat? Did they take a detour past the sun? How could this possibly have melted?

[Jesus Echavarria]‘s friend had similar fears and suspicions about a box he is going to have shipped from Spain to China. So [Jesus] got to work and built this nice datalogger to discover the truth. Since the logger might have to go for a couple of months, it’s an exercise in low power design.

The core of the build is a humble PIC18. Its job is to take the information from an ambient light, temperature, and humidity sensor suite and dump it all to an SD card. Aside from the RTC, this is all powered from a generic LiPo power cell. The first iteration can run for 10 days on one charge, and that’s without any of the low power features of the microcontroller enabled. It should be able to go for much longer once it can put itself to sleep for a period.

It’s all housed in a 3D printed case with some magnets to stick it to shell of the shipping container. Considering the surprisingly astronomical price of commercial dataloggers, it’s a nice build!

Surf’s Up! Virtually

November 1, 2016 by Al Williams No comments

While it may or may not be true that if everybody had an ocean they’d be surfing like California, it is true that with a water pump, some copper tape, and a few scraps you can make a surfing simulator that sprays you if you don’t keep your balance.

You can see the simple device in operation in the video below. We presume [Adi_10] actually surfs, but we can’t comment on the realism of the simulator. There’s no computer. Just a switch made from the base and the balance board.

Continue reading “Surf’s Up! Virtually” →