Printing Text With A Chart Recorder

A chart recorder printing 'Hello World'

Chart recorders are vintage devices that were used to plot analog values on paper. They’re similar to old seismometers which plot seismic waves from earthquakes. The device has a heated pen which moves across a piece of thermally sensitive paper. This paper is fed through the machine at a specified rate, which gives two dimensions of plotting.

[Marv] ended up getting a couple of discontinued chart recorders and figured out the interface. Five parallel signals control the feed rate of the paper, and an analog voltage controls the pen location. The next logical step was to hook up an Arduino to control the plotter.

However, once the device could plot analog values, [Marv] quickly looked for a new challenge. He wanted to write characters and bitmaps using the device, but this would require non-continuous lines. By adding a solenoid to lift the pen, he built a chart recorder printer.

After the break, check out a video of the chart recorder doing something it was never intended to do. If you happen to have one of these chart recorders, [Marv] included all of the code in his writeup to help you build your own.

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Marvin’s Marvelous Mechanical Museum

Don’t call it an arcade. There are arcade-like things about it… like dance-based video games, Skee-ball, and tickets — oh so many tickets. But Marvin’s Marvelous Mechanical Museum is a one-of-a-kind that you need to visit next time you’re in the North suburbs of Detroit, Michigan.

[Marvin] was there in person, as he is many days. He talked with us for a few minutes and we’ve folded his interview, along with footage of many of the attractions, into the video above.

He’s been collecting for more than three decades. The attractions are packed into every bit of floor space, spilling up onto the walls, and hanging from every spot in the ceiling. There are true antiques from both home and abroad that could be referred to as automatons, rows of fortune tellers, a track of large airplane models that make a loop around the establishment when fed a quarter, and much more.

Some of the attractions were build for him, like the robot band you can make out behind [Marvin] during the interview. It is a MIDI-based build that allows songs to be selected from a touchscreen. Soon to be on exhibit is a Tesla-coil-based offering which [Marvin] commissioned after taking second place to [Nicolai Tesla] on a list of oddest museums.

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A Fully Mechanical 3D Printer Is Mind Blowing

mechanical 3d printer

It’s been a while since we’ve been seriously impressed with a project like this one. [Daniël de Bruin], a student at the Art Academy in Utrecht has just put the final touches on his mechanical 3D printer.

That’s right. Mechanical.

No computers, no motors, just the power of gravity. It could have been built 100 years ago.

The machine uses a 15kg weight to power the mechanism — it does need to be reset during the print, but that’s a small price to pay for this kind of mechanical automation.

He uses a type of clay in a paste extruder that slowly deposits the material on the build platform. To program the machine, there is a small guiding mechanism that follows the contour of a bent aluminum wire. This allows you to make any number of symmetrical and circular objects.

[Daniël] says he was inspired to build this machine because he loves 3D printing — but at the same time, he feels like it’s kind of like cheating. Beyond pressing the print button, there’s no real human interaction.

I love technology but how can I reclaim ownership of my work? Perhaps by building the machine that produces the work. Perhaps by physically powering the machine, which I built, that produces the work. in hopes of rediscovering the sense of having created something, I create.

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BigBoy Advance, A Giant GBA For Big Hands

big boy advance

Ever wish Game Boys came in a slightly larger size? [John], aka [Bacteria] of Bacman, decided to try something different with this retro console mod — the BigBoy.

In case you’re not familiar with the Bacman website, it’s a site dedicated to retro video game console modding — and our hacker, [John] is the man behind the scenes. We’ve shared plenty of their projects before.

The BigBoy is basically a Game Boy Advance — with an 8″ display. It uses the electronics from a knockoff copy of a RetroBit in a custom case that [John] vacuum formed at home. He sketched out the proposed outline, built a mold out of plastic sheets and hot glue, and created a concrete dummy mold for the vacuum former — meaning if he ever wanted to recreate this project it would be a piece of cake!

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Whimsical Homemade Wimshurst Machine

gge5

Got some empty plastic bottles in your recycling bin or cluttering up your desk? Then you’ve got a large portion of the material you need for building your own Wimshurst machine like [Thomas Kim] did. This demonstration and build video is one of the many treasures of his YouTube channel. He shows the machine in operation and then spends several real-time minutes showing how he made the heart of it using plastic bottles, the conductive brush from a laser printer, discarded CDs, and a bunch of copper wire. As a bonus, he removes the conductive material and paint from a CD with a homemade taser. As a super special bonus, there’s no EDM soundtrack to this video, just the sounds of productivity.

The Wimshurst machine is an electrostatic generator that slightly predates the Tesla coil. It works by passing a charge from one spinning disk to another disk spinning in the opposite direction. When the charge reaches the collecting comb, it is stored in Leyden jars. Finally, it gets discharged in a pretty spark and the cycle begins anew. Once you’re over shocking your friends, use your Wimshurst machine to make an electrostatic precipitator.

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Home Made Lightbulb Is A Fun Proof Of Concept

home made lightbulb

Do you ever look at some of the most classic and world-changing inventions and think, “Darn, I totally could have invented that if I was born 100 years ago!”. Sometimes its a lot of fun to try to recreate these inventions making use of period-accurate materials — like this jar-based carbon filament light bulb!

The project is made out of simple household materials that you probably already have. A jar, some pencil lead, a clothes hanger, some nuts and bolts, a bit of silicone, piano wire and a bit of JB weld. The only thing you might not have is some compressed CO2 — unless you have a kitchen fire extinguisher, a paintball gun, or one of those home-made pop carbonation machines… Alternatively you can just buy some dry ice and let it sublimate in the bottle before you seal the bulb.

No fancy tools are needed (except for an air nozzle for filling the bulb), and it’s not too difficult to construct. The trickiest part is probably drilling small holes through the screw, but if you choose nice brass screws it’ll be quite easy to do.

Once it’s all assembled, plug it into a car battery and enjoy your inefficient 1-lumen light bulb! Still — pretty fun experiment!

A Simple Commodore 64 Cart Dumper

c64

While [Rob] was digging around in his garage one day, he ran across an old Commodore 64 cartridge. With no ROM to be found online, he started wondering what was stored in this ancient device. Taking a peek at the bits stored in this cartridge would require dumping the entire thing to a modern computer, and armed with an Arduino, he created a simple cart dumper, capable of reading standard 8k cartridges without issue.

The expansion port for the C64 has a lot of pins corresponding to the control logic inside these old computers, but the only ones [Rob] were really interested in were the eight data lines and the sixteen address lines. With a little bit of code, [Rob] got an Arduino Mega to step through all the address pins and read the corresponding data at that location in memory. This data is then sent over USB to a C app that dumps everything in HEX and text.

While the ROM for just about every C64 game can be found online, [Rob] was unlucky enough to find one that wasn’t. It doesn’t really matter, though, as we don’t know if [Rob] has the 1541 disk drive that makes this cart useful. Still, it’s a good reminder of how useful an Arduino can be when used as an electronic swiss army knife.