Working out in the shop is usually super fun but if it’s summertime, watch out, it can get hot! We’ve all been there and we’ve all wished we could do something about it. Well, woodworker and general DIYer [April] has stepped up to the plate and built a portable low-buck AC unit to cool her shop down to an acceptable temperature.
The unit is very simple and starts off with an old thrift store cooler. A hole is cut in the back of the cooler to make room for a fan that is directed to blow air inside the cooler and across blocks of ice. The air cools down as it passes over the ice and leaves out the top of the cooler through five 90-degree PVC elbows. After all the inlets and outlets were caulked, the entire unit was given a monochromatic black paint job.
[April] says you can feel the cool air blowing from about 5 feet away from the unit. She has measured the output air temperature to be 58-62ºF. If using loose ice cubes, the unit will work for 2-3 hours. Freezing milk jugs full of water gets about 5 hours of use.
This week we’re giving away 125 Teensy-LC Boards. You’ve sat on the sidelines long enough. Time to write down your Hackaday Prize idea and get it entered!
It isn’t just the big prize (a trip into space) on the line. Each week we’re giving away things to help your build. Below you can see the 50 projects which won a LightBlue Bean from last week’s giveaway. This week it’s a huge number of Teensy-LC boards going out to those who need them. These little wonders pack a real punch, with a 48 MHz ARM Cortex-M0+ that has 62K of flash, 8k of RAM, plenty of IO and a 12-bit analog module for both input and output! You’ll also be eligible for each of the future weekly giveaways… we’re distributing $50,000 in prizes to hundreds of projects over 17-weeks!
Entering is easy. Write down your idea to help solve a problem faced by a wide range of people. Start fleshing out your build plan. Pictures are a huge help, even if they’re just a hand-drawn sketch on some paper! Your best bet at getting recognized for a giveaway is to post a new project log which mentions how you would add this Teensy board to your creation.
Last Week’s 50 Winners of a LightBlue Bean
Congratulations to these 50 projects who were selected as winners from last week. You will receive a LightBlue Bean which combines Bluetooth LE with an ATmega328 in a nice little package ready for prototyping. Don’t forget to post pictures and information about what you build with these little wonders!
TechCrunch Disrupt is on this week, and that means we get to see which members of tech media don’t understand basic physics. So far, it’s writers from Engadget, The Mirror, Business Insider, TechCrunch, and four judges on the TC Disrupt stage. What is the consequence of not understanding the implications of the conservation of energy? Glowing support for a cell phone that can charge itself.
The offending Disrupt startup is Nikola Labs, and they’re gearing up to launch a Kickstarter for a very special iPhone 6 case. This case uses small, energy-harvesting antennas to gather RF energy from the cellphone tucked away in this case. This energy is then sent to a rectifier where it is converted into something the Apple Lightning connector can sip power from. According to Nikola Labs, this RF harvesting antenna takes energy from the transmissions of the iPhone 6 entombed in this case, converts it to about 5 Volts, and uses that to charge the iPhone battery.
I know that seems difficult to understand, so here’s a simple analogy: you have a flashlight with a battery and a solar cell. The solar cell recharges the battery. If this were a Nikola Labs flashlight, you would recharge it by shining the flashlight onto the solar cell.
That is the simplest explanation of what the Nikola Labs cellphone case does, and illuminates the limitations of what it can do. If the ‘energy harvesting circuit’ collects power from the device it is recharging, it will reduce the transmission power of whatever is transmitting. With the cellphone case, you’re spending transmission power (plus efficiency losses) to recharge the battery. That means poorer reception and fewer bars. In the solar-recharging flashlight analogy, the flashlight would either be dimmer, or you could only use it part of the time.
It’s also why Nikola Labs claims their case will only recover 30% of the battery life of an iPhone 6; the battery isn’t solely dedicated to a transmitter – there’s a display and a CPU to account for in the power budget.
To Nikola Labs’ credit, this is at least a novel application of the RF energy harvesting trope that has been making its way around Kickstarter and tech blogs for a few years. Nearly every other RF harvesting idea that has been pitched in recent memory decouples the transmitter (or ‘generator’, I guess) with the product or receiver. The square cube law is an evil mistress, and if you’re wondering why these devices don’t work, [ch00f], a guy with an actual engineering degree, has a great writeup of one of these products over on Drop Kicker.
The Nikola Labs cellphone case bucks this trend by looking at the shortcomings of these devices; an RF rechargeable Bluetooth tag won’t work if you place it a foot away from a WiFi router, but it just might if you tape it to the antenna. This is the idea behind Nikola Labs’ invention: harvest energy from a few millimeters away from the cell phone’s antenna. According to Nikola Labs, their engineer, [Chi-Chih Chen] has a patent in the works for this. This patent application has not been published yet.
In theory, the Nikola Labs cellphone case will actually recharge your battery, but at a price: you’d be wasting your transmission power on recharging the battery. It’s a false economy that you’ll be able to fund on Kickstarter next month for $100 USD. If you’re only looking for more battery life, walk into any gas station, buy a $10 USB power bank/battery, and have enough portable power to recharge your iPhone battery to 100%. That’s not a sexy solution, it doesn’t reference [Nikola Tesla], and it’s not snake oil that tech media is lapping up like dogs. Pity.
If you need to build a robot to carry something, you need a bit motor, right? Not so with these tiny robots out of Stanford’s Biomimetic Dexterous Manipulation Laboratory. One of these 12g MicroTugs can drag a 600g mug of coffee across a table, or even a 12kg weight. According to the authors, it’s a, ‘capability … comparable to a human dragging a blue whale.’ Square-cube law notwithstanding, of course.
What makes these little robots so strong? It’s not the actuators; it’s their feet. On the bottom of this robot is a material that uses mechanical anisotropic adhesion, a fancy material that only sticks to flat surfaces when it’s being pulled in a specific direction.
The best description of this material inspired by gecko feet would be this video, also from the Stanford BDML lab. It’s a neat material that we’ll probably find in Post-It notes in a decade, and with a single motor, a tiny robot can lift thousands of times its own body weight.
Canada! Just in time for Spring to hit. I went to Toronto to speak at FITC, an arts and technology conference, co-host a Hackaday meetup with HackLab TO, visit the DigiPlaySpace at TIFF, and to check out Globacore’s new digs.
FITC is a conference which celebrates the creativity in technology. Pictured above is Diorama Rama designed by [Christopher Lewis] and [Creative Technologists of Toronto] and built over 4 days by participants at FITC. The buildings are laser cut paper, and participants create a simple circuit using an ATtiny. A message is coded into the chip in ASCII and the buildings blink an individual message back in Morse code, each building blinking a different message. It’s pretty interesting to use a Morse –> ASCII phone app (Morse Tools) to read the messages.
Looking at Diorama Rama with Morse Tools
Hackaday Prize judge [Micah Elizabeth Scott] gave a talk about her work. [Jessica Rosenkrantz] of Nervous System spoke about her company’s process when designing mathematically based objects. She spoke about her 3D printed dress pictured below and how it was made. Amazing! I also got to show off my newly minted Breathe project at FITC.
Kinematics by Nervous System
After FITC ended, HackLab co-hosted a meetup with us. A team from HackLab was a 2014 Hackaday Prize Semifinalist and won $1000 in components with their Retro Populator, a Pick and Place machine retrofit onto a 3D printer. We had beer as well as almond-cream flavored non-alcoholic drinks from the Luma Droid, a drink mixing robot. HackLab is a good-sized hackerspace, with a huge room for a meetup, a full kitchen and vegan dinner served frequently, plus a shop tools room all by itself.
Eric Boyd kicks it off
Luma Droid!
3D router
Retro Populator
Full house at HackLab
Among the lightning talks, [Pearl Chen] brought her Intel Edison-powered alarm clock that has but one function — to tell her when she is running late. [Johannes van der Horst] brought a USB current monitor that had many of us fascinated for about an hour at the end of the evening, plugging in a phone or a battery just to see the numbers climb. [Eric Boyd] talked about the DIY Bio projects that are going on at HackLab. They are testing meat using PCR to see if it is indeed, beef. Ew.
[Andrew Kilpatrick] of Kilpatrick Audio showed us an older version of his synthesizer before showing us his newest revision, Phenol, which looks pretty slick.
Pearl Chen
Johannes van der Horst’s USB current meter
Johannes van der Horst’s USB current meter
Pearl Chen’s smart clock
Andrew Kilpatrick’s Phenol synth
[Hugh Elliot] spoke about a light-photography project. [Leif Bloomquist] spoke about a gaming glove project that Hackaday had previously covered. Leif had a Commodore 64 with him and all the games on it fit into 1 GB! [Nadine Lessio] discussed how many programs claim that you can become an expert in a few hours, but in fact, things are not easy. [Jay Vaidya] showed us an IFTTT hack which controls heaters and AC. [Andy Forest] showed us an impressive interactive model of Ontario’s power system that kids at Steam Labs created.
Leif Bloomquist’s gaming glove
IFTTT hack
That was a super fun meetup! Thanks HackLab for hosting. We’ve got a bunch of upcoming meetups and larger events in LA, NYC, Bangalore, San Francisco and Shenzhen. Check our events page for what, where, and when, We’d love to see you.
I stopped by TIFF’s Bell Lightbox to see the DigiPlaySpace exhibit. [Micah Scott] did a collaboration with Ryerson University’s RTA School of Media which welcomes you as you walk in. Note: all photos are lifted directly from TIFF.net’s website.
Headrush
Forest
Alien
My final stop on this tour was to visit Globacore’s new offices. We spent a day or so hacking on a VR controller for their newest game called Power Cube. Power Cube is an Oculus Rift experience with a custom game controller holding an accelerometer, a gyroscope and magnetometer that links into the game directly.
The filaments consist of 28 LEDs connected in series. The blue LEDs are covered by the typical yellow phosphors to make them glow white. It’s interesting to note that some of the filaments use a removable silicone sleeve to hold the phosphor coating, while others are coated with a resin material. The LEDs themselves are bare dies mounted to a metal strip and joined by bond wires. The entire strip can be bent, but be careful, or you’ll break the fragile bond wires.
The strips do require a fair bit of voltage to operate. The entire strip runs best at around 75 and 10~15 mA, while putting out about 1 Watt of light. [Mike] tested a strip to destruction by pumping 40 mA through it. Predictably the strip went out when the bond wires melted. The surprising part was that the strip blinked back on as the wires cooled and re-connected. The strip and wires were working as a temperature controlled switch, similar to the bimetalic strip found in old fashioned “twinkling” incandescent Christmas lights.
Not satisfied with simple tests, [Mike] went on to build a clock using the filaments as elements of a seven segment display. Inspired by numitron and minitron displays, [Mike] built a single sided PCB which held the clock circuit on the bottom and the LED filaments on top. The filaments are spaced off the board by tall wire wrap sockets, which proved to be difficult to keep from shorting out. Texas Instruments TPIC6B595 chips were used to control the LED filaments. Logically the chip functions the same as a 75LS595, which means it can be driven with a SPI bus. The open drain outputs can handle 50 volts – which makes them perfect for this application. The clock is tremendously bright, but there is still a bit of room for improvement. [Mike] notes that the phosphor of un-powered filaments tend to glow a bit due to light absorbed from nearby illuminated filaments. He’s experimenting with color filters to reduce this effect. At full power though, [Mike] says this clock would easily be daylight readable, and we don’t doubt it!
[Mike’s] final test was a bit whimsical – he built a cube entirely from the LED filaments. The cube looks awesome, but we can’t wait to see who will move things into the 4th dimension and build a tesseract!
Hackaday is getting back into the swing of doing reviews, and with that comes reviews of the tool du jour, 3D printers. I have some reservations about reviewing a 3D printer; they’re a new technology, and what may be standard today could be hopelessly outdated in a few months time. Remember geared extruders? The new hotness is, apparently, direct drive extruders.
This is a review of the Printrbot Assembled Simple Metal. If you need any evidence that reviews of 3D printers have a shelf life, you only need to look at the Getting Started guides for this printer. When I bought my Simple Metal, the Printrbot recommended software stack was Slic3r and Repetier-Host. Barely three months later, Cura is now the Printrbot recommended software stack. If you think a simple change in software is inconsequential, check out these prints:
Prusa i3 X-carriages. Left sliced by Slic3r, right sliced by Cura
The print on the left was sliced with Slic3r. The print on the right was sliced with Cura. Notice the small teeth that grip the timing belt on each of these prints. With the Cura-sliced print, everything is fine. The Slic3r-sliced print is a complete failure, not of the machine, but the recommended software for the machine.
Therefore, if the goal of writing a review is to have a definitive opinion of a piece of equipment, a number of questions must be addressed. Since most 3D printing software is open source, should software be included in the review? Is the value proposition of a 3D printer simply a function of price to build volume (this seems to be the standard metric now), or are there intangibles? Should the review cover the quality of prints out of the box, or should the review only focus on print quality after dozens of hours of tweaking? I simply don’t know the answers to these questions, and I suspect you couldn’t get any two people to agree on the answers to these questions.
With that said, I feel I have used this printer enough to make a judgment call as to if this printer was a good buy.
