Fail Of The Week: Battery Packin’

September 25, 2014 by Kristina Panos 35 Comments

[NeXT] got himself an IBM ThinkPad TransNote and yeah, we’re pretty jealous. For the uninitiated, the TransNote was IBM’s foray into intelligent note transcription from roughly fifteen years ago. The ThinkPad doesn’t even have to be on to capture your notes because the proprietary pen has 2MB of flash memory. It won an award and everything. Not the pen, the TransNote.

Unfortunately, the battery life is poor in [NeXT]’s machine. The TransNote was (perhaps) ahead of its time. Since it didn’t last on the market very long, there isn’t a Chinese market for replacement batteries. [NeXT] decided to rebuild the replacement battery pack himself after sending it off with no luck.

The TransNote’s battery pack uses some weird, flat Samsung 103450 cells that are both expensive and rare. [NeXT] eventually found some camera batteries that have a single cell and a charge controller. He had to rearrange the wiring because the tabs were on the same side, but ultimately, they did work. He got the cells together in the right configuration, took steps to prevent shorts, and added the TransNote’s charge controller back into the circuit.

Nothing blew up, and the ThinkPad went through POST just fine. He plugged it in to charge and waited a total of 90 minutes. The charging rate was pretty lousy, though. At 94% charge, the estimated life showed 28 minutes, which is worse than before. What are your thoughts on the outcome and if it were you, what would be the next move?

Fail of the Week is a Hackaday column which runs every Wednesday. Help keep the fun rolling by writing about your past failures and sending us a link to the story — or sending in links to fail write ups you find in your Internet travels.

Hackerspace Tours: Omaha Maker Group

September 24, 2014 by Kristina Panos 10 Comments

Members of the [Omaha Maker Group] in Omaha, Nebraska affectionately call their space The Makery. This hearkens back to their humble beginnings in a 900 square foot space that formerly housed a bakery. There was one measly electrical outlet and they had to travel to the nearest restroom, often on vehicles they made. It was in this small space where they built the workbenches and forged the friendships that created the inviting hangout they have today.

[OMG] has been in their current, more centrally located space for the last two years. It was there that I met [Eric] and [Ben] for a few hours in the evening before Maker Faire, for which they are largely responsible. [Eric] had spent the day setting up at the Omaha Children’s Museum and he and [Ben] were kind enough to give me a detailed tour.

The new space is a progression of rooms that begins with a combination lounge and meeting space. Here you’ll find the beer and snacks, the brag wall full of framed articles, and one of the remote controllable web cams. A few of the founding members have since flung themselves around the world, but are able to participate through these links. The best part of this room is either the PVC-framed Raspi MAME cabinet or the sign on the bathroom door which doesn’t discriminate against androids.

Next up is a smallish room with their 3D printer, a modified Mendel with a spool holder made by one of the members. There’s a large pile of glue sticks next to it to help prints adhere to the bed. That was a new one to me. [Ben] says they work almost too well. Next to that is their K40 C0₂ laser cutter that they modified to operate only when closed (!). They’ve also added LEDs and an exhaust fan. The cutter was internally crowdfunded in about three days. This method works well for them according to [Eric]; no one spends money on equipment they won’t use. They are currently in the process of building a second, bigger one using a donated frame.

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Push-Button Degaussing For An Arcade CRT

September 23, 2014 by Kristina Panos 21 Comments

[Ed] was tasked with adding push-button degaussing to an arcade cabinet’s CRT console. The display can be rotated to portrait mode for games that require it, but each time this is done, the magnetic fields get out of whack.

Fortunately, the schematics arrived with the display. [Ed] found that the degauss coil is connected in series with a PTC fuse in an odd arrangement that he didn’t agree with. He decided to use an SSR to switch the coil, and after making lots of transistor-based designs on paper, grabbed a nearby Arduino.

[Ed] took off the PTC and soldered in two wires to its pads for the SSR. He added a wire to the power supply decoupling cap to power the new deguassing circuit and connected the SSR to the Arduino as an open collector input. There was just enough space available to mount the relay to the frame’s base and the Arduino on the side. [Ed] wrote a short method to trigger the SSR and reconnected the PTC fuse. Now it degausses at power up as well as on demand.

Retrotechtacular: The Diesel Story

September 23, 2014 by Kristina Panos 50 Comments

The diesel engine was, like many things, born of necessity. The main engine types of the day—hot bulb oil, steam, coal gas, and gasoline—were not so thermally efficient or ideal for doing heavy-duty work like driving large-scale electrical generators. But how did the diesel engine come about? Settle in and watch the 1952 documentary “The Diesel Story“, produced by Shell Oil.

The diesel engine is founded on the principle of internal combustion. Throughout the Industrial Age, technology was developing at breakneck pace. While steam power was a great boon to many burgeoning industries, engineers wanted to get away from using boilers. The atmospheric gas engine fit the bill, but it simply wasn’t powerful enough to replace the steam engine.

By 1877, [Nikolaus Otto] had completed work on his coal gas engine built on four-stroke theory. This was the first really useful internal combustion engine and the precursor of modern four-stroke engines. It was eventually adapted for transportation with gasoline fuel. In 1890, the hot bulb oil engine was developed under the name Hornsby-Akroyd and primarily used in stationary power plants. Their flywheels had to be started manually, but once the engine was going, the bulb that drove combustion required no further heating.

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THP Semifinalist: Honeybee Hive Monitoring

September 23, 2014 by Kristina Panos 14 Comments

[Ken] keeps his bees remotely and can’t check on them as often as he might like to. He wanted some way of knowing when they were out of space, because that slows down their nectar collection. He knew he could do this by remotely tracking the weight and internal temperature of the hives.

His first prototype revolved around a postal scale that couldn’t be turned off between readings. This meant that he needed a bigger solar panel and battery than originally intended. For about a week, the hives were sending data to Thingspeak through an Arduino Fio over XBee.

The current iteration measures the load cells with an HX711 24-bit ADC. This sends the scale data to an Apitronics Bee unit, which adds in temperature data from the hives and sends everything to an Apitronics Hive. [Ken] will also stream it to a cloud service so he can monitor them in real-time. [Ken] wants to see as much data as possible and contribute to NASA’s HoneyBeeNet program, so he has a second Bee unit set up to handle a nearby Apitronics weather station.

The project featured in this post is a semifinalist in The Hackaday Prize.

Sweet Stepper Of [Jeremy]’s Rocks Out With Its Box Out

September 18, 2014 by Kristina Panos 12 Comments

Inspired by the floppy drive orchestras of others, [Jeremy] has built a Pi-driven MIDI music box with stepper motor resonators and outlined the build on hackaday.io.

Control for the motors comes from an Iteaduino Mega 2560. The music starts as a MIDI file, gets processed into a text file, and is played over serial by a Raspberry Pi. He’s added percussion using K’NEX instruments and 9g servos, which we think is a nice touch. It can be powered via LiPo or from the wall, and [Jeremy] baked in protection against blowing up the battery. As he explains in the tour video after the break, the box is clamped to a wooden table to provide richer sound.

[Jeremy]’s favorite part of the build was enclosing the thing as it was his first time using panel-mount components. Stick around to see a walk-through of the guts and a second video demonstrating its musical prowess.

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Fail Of The Week: Robotic 1950 Mercury Boogies, Won’t Come Back From Dead Man’s Curve

September 18, 2014 by Kristina Panos 14 Comments

[Dave] wanted to make an Arduino robot out of a remote-control 1950 Mercury. He removed the RC portion from the car and kept the drive and steering motors. The idea was to use three ultrasonic rangefinders in the grille real estate and move the car forward based on the longest distance detected.

He initially used a Seeed motor controller and some Grove cables soldered to his sensors to power the steering. It went forward, but only forward, and [Dave] decided the motor controller and the car’s steering motor weren’t playing well together.

[Dave] had the idea to use relays instead to both power the motor and determine polarity. Now, the Merc was turning and avoid obstacles about half the time, but it was also getting dinged up from hitting walls. He figured out that his sensor arrangement was making the car turn immediately and decided to give the program information from the wheels with a reed switch and a rare earth magnet. The only problem is that the caliber of magnet required to trip the reed switch is too heavy and strong. [Dave] and has concluded that he simply can’t exercise the kind of control over the car that he needs. and will build his own robot chassis.

Update: Check out a video of [Dave]’s car after the break.

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