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October 3, 2009

Building a CPU from scratch

Brad has a good start on what looks to be an ambitious electrical engineering project. Inspired by the Apollo guidance computer, he is constructing his own CPU using TTL logic chips and wire wrap. He's taking a little liberty with the design, using EEPROM chips for opcode decoding instead of hardwiring it all, but I think that can be excused. If you want to follow along and get some tips for your project, he also has a wiki to document his progress.

October 1, 2009

Want a lathe? Make one from junk

This project is kind of mad, but the results could be pretty useful. Instructables user catwood guides you through the process of building a wood lathe from mostly discarded parts. Along the way you will need things like the motor from a washing machine and the frame from a bike. It might make sense to buy or construct a more sturdy piece of equipment if you plan to make wood turning a full time hobby, but for light duty projects I could definitely see this coming in hand.

September 28, 2009

Bath-tub steam boat really works!

Steve writes in with these build instructions for a classic bathtub playtoy, the tugboat. At first glance it seemed like a regular old wooden play boat, but there is something cooler here- it has a working steam engine!

I hadn't heard of pop-pop boats before, but apparently they used to be common toys. The pop-pop motor is a phase-change heat engine (fancy name for a device that converts heat into kinetic energy), and the popping sound is caused when the water turns into steam and causes the metal cavity to expand. Here is a video of someone else's build:

This looks like a pretty fun experiment- anyone make one of these before? Bonus points if it can be remote controlled.

September 24, 2009

Frankenstein, an all-tube home theater system

What could be better than a tube amplifier? How about an entire surround sound system built using tubes! Radar hacker Greg Charvat built such a beast back in 2005, and he refers to it affectionately as Frankenstein. Besides being an excellent, high-powered stereo, word on the street is that it also functions as a very capable space heater.

This is a good example of a project that has become completely out of control. At some point in the past I decided to build an all-tube home theater system (except for the DSP stuff that decodes the various Dolby 5.1, and etc signals). The result of this effort is affectionately known as "Frankenstein." It consists of 5 class AB tube power amplifiers, tube pre-amps, and a Dolby 5.1/DTS digital signal processor, for a total of 27 vacuum tubes. Each power amplifier is capable of over 400 watts peak output. All of the equipment is mounted in a 7' tall WW2 vintage equipment rack.

Schematics and engineering notes are available on his website, if you are up to the challenge.

September 23, 2009

Circuit bent camera reacts to sound

Gijs Gieskes hooked up a circuit bent camera to a VU meter to create the VU Cam. I really enjoy the neat look of his homebrew circuit board, and the repeatable-looking results it achieves on the camera. He also includes a schematic, in case you want to try making your own.

September 18, 2009

How-To: Cure colorblindness in an adult primate

OK, OK, this is probably something you shouldn't try on yourself, a loved one, or even a close friend. Still, it's pretty flippin' amazing: a full-grown animal, permanently (apparently) cured of a genetic defect by a few injections. Can X-people be that far behind?

(That's a rhetorical question, BTW; those of you who know the real answer to that question is "yes," just chill and give me my moment.)

Here is the original abstract at Nature.

September 17, 2009

Paris 2007, a popularity meter

Tim Schwartz made clever use of an old indicator dial with his piece Paris, 2007. He is using an embedded system to monitor realtime search patterns, in order to determine which Paris is more popular. The meter is constantly updated to show the latest results. It sounds like a pretty fun project to attempt. Anyone know how to get a realtime feed of people's search patterns? [via core77]

September 15, 2009

The impossible rose

To produce a naturally blue rose has been a dream of horticulturalists for almost as long as people have been breeding flowers. It turns out to be essentially impossible to do by traditional plant husbandry, and attempts have proved futile for so long that the blue rose itself has become a symbol of the impossible or the seemingly impossible, and only the rarest achievements call for their presentation as gifts. And until recently, even those rare occasions had to be served by artificially blue roses made by growing white roses in tinted water. Now, however, the Japanese company Suntory, in partnership with Australia's Florigene, have created a transgenic rose which incorporates a petunia gene to achieve a pale lilac color which is really only barely blue. It took them 13 years of work to do it, however, so I guess they've decided pale lilac is close enough.

September 10, 2009

Converting an old keyboard to MIDI

Giancarlo Todone writes to tell us about his homebrew solution for converting an old keyboard to MIDI. The project is especially nice because he went beyond the standard on/off key detection, and added full velocity sensitivity for the keys. This means that the keyboard can detect how fast a key is pressed, allowing the keyboard to be played more expressively. Full schematics and source code are available on his website, however the writeup is in Italian.

September 4, 2009

Repurposing cement bags as bellows

These enterprising blacksmiths make their wares using bellows made from cement bags.

[via afrigadget]

September 3, 2009

Pattern kits for Gingery machines?

So here's a random idea I had.

Most readers are probably familiar with Dave Gingery's series of books on building a set of homemade machine tools. The technique, basically, involves building an inexpensive homemade charcoal furnace and crucible for melting aluminum, then using traditional green-sand casting techniques to mold the various machine parts from wooden patterns. Much of the content of Gingery's books details the construction of these patterns.

As I have recently discovered, however, lost-foam casting is a much more accessible metal-casting technique than traditional green-sand. It requires no special flasks, no special sand, and no consideration of parting-line placement in designing patterns. Basically you make your pattern from styrofoam, bury it in sand, and pour hot aluminum into it. The foam vaporizes and diffuses into the sand, and you're left with a perfect aluminum duplicate. The only downside is that the pattern itself is destroyed, so if you screw up the casting or want more than one copy of a part you need a new pattern.

Here's what I'd like to see: Some enterprising soul with a CNC foam cutter could sell kits of the Gingery machine patterns ready-cut in XPS foam.

Then, if you wanted to build the Gingery tools, you wouldn't have to spend a lot of time learning the art of green-sand casting, or building the special tools required, or carpentering on the patterns themselves, most of which will only be used once anyway. You'd just buy a few ounces of pre-cut foam patterns in a kit, bury them in sand, and start pouring hot aluminum right away. Depending on sales volume, it might even be practical to make the foam patterns in conventional molds, the same way styrofoam packaging inserts are produced, at lower cost than CNC machining.

If you're interested, supportive, or (for your own unfathomable reasons) furious, feel free to sound off in the comments.

September 2, 2009

Worlds largest bristlebot?

The fine folks at i3 Detroit built this giant, ridable bristlebot using a large motor, a pipe for an offset weight, and a bunch of push broom heads. They claim it is the worlds largest, which I tend to believe. Does anyone know of a larger one?

Also, I think the only proper way to respond to this is to make an even larger bristlebot and challenge them to a race. Detroit makers, you are on!

Photo credits: Matt Mets, Dug Song

September 1, 2009

Fun with linkages

All of that gear pr0n got me thinking about ridiculous mechanical gadgets, and what better than a mechanical linkage that can square a complex number? It's probably not as useful as the Peaucellier's Cell or Watt's Linkage, and I don't think it is possible to build, however I really like this somewhat extreme example of translating mathematical operations into mechanical computers. In the above calculator, the x-axis represents the real portion of the number, and the y-axis represents the imaginary portion. To make the 'calculator' work, you drag the green dot to the location of the number you want to square, and the location of the red dot tells you the answer.

You can try it out for yourself on Dori Elder's thesis site from 1999!

August 26, 2009

Repairing a vintage electromechanical metronome

This is an interesting look at the inner workings of a vintage electromechanical metronome. Even if you couldn't get it to work, or didn't want to, it would make a great enclosure for your next electronics project. I suspect the warranty is officially voided!

Passing behind a church-operated thrift store a month or two ago, I saw a black bakelite box in the area where they discard stuff they don't want, about to get rained on. After seeing that it was a metronome, I rescued it and made it mine. This weekend I tried it out for the first time and ended up repairing the motor. The motor's workings were unfamiliar to me, but its repair was self-evident.

In the Maker Shed:

MKWVP4-2 2.jpg
MAKE: Warranty Voider - Leatherman "Squirt" P4 (plier version)

August 24, 2009

Slewbot the writing robot

There aren't many details about the build of this drawing robot by David Williamson, however I really like the concept of using two simple (and presumably high-repeatability) actuators to do the drawing, rather then trying to force a conventional two-wheeled robot to do the job. I also appreciate the fact that his site shows a large number of different prototypes, and explains the features and drawbacks of each one.

My idea is to make little courier bots out of these, that you could program with a secret message and send off to someone as a surprise. Have you seen or designed any other bots that would be capable of this? Any other ideas about what to do with them?

How-To: Lost foam metal casting

Most home metal-casters use traditional green-sand molding techniques to cast parts. Typically, a two-part molding flask is packed with specially-treated sand around a pattern, then the flask is carefully opened, the pattern removed, and the flask reassembled, being careful not to disturb the sand impressions, leaving a negative space in the exact shape of the original. In lost-foam casting, however, the pattern does not have to be removed before pouring in the molten metal; rather, the hot melt simply vaporizes the foam as it flows in, and replaces it. This process has a number of advantages to recommend it over the traditional technique. It does not require a two-part flask, and can be performed in a simple metal bucket. Nor does it require special sand, or special techniques for handling it. Dave Kush has a great overview on his site. Among other things, Dave uses the lost-foam process to cast homemade linear bearings for his CNC equipment.

How-To: Make a glass skull by lost wax casting

Glasskulls.com, though short on "who," is long on "how," featuring nice big, clear photos illustrating the process of going from wax master to finished art glass casting. Inferring from the scattered comments, I think the artist's name is "Donn." If so: Nice work, Donn, and thanks for showing us how it's done.

August 20, 2009

Make a cardboard dragon

I love this elaborate cardboard dragon posted by Creativeman on Instructables. In fact, upon further inspection you'll see that he's got about 11 cardboard projects uploaded to the DIY site. Fun stuff!

August 13, 2009

Hack your cooler: Air chillers

Sitting here in our un-airconditioned hackerspace after a long bike ride has got me thinking about how to cool off, and what better way than to make your own air chiller? It turns out there are a number of different ways that makers have figured out how to do this. I wish I had one of these here with me now!

Pete H. made this cool-looking device that uses cool water pumped through copper tubing to chill the air being blown by a fan.

And here's a more advanced, radiator-based design that should be more efficient than the copper tube version above.

Finally, here's an Instructable about how to make a battery-powered version for when you are on the go.

Any other ideas about making a portable air chiller using a cooler? How about a portable swamp cooler that has an icy reservoir of liquid to keep you cool? A portable mister that uses gravity or compressed air to keep an area cool? An astronaut helmet that keeps your head in a cool bubble? Share your ideas in the Comments.

DPRG trebuchet

It looks like the Dallas Personal Robotics Group (DPRG) would make a great team for our MAKEcation trebuchet challenge. Watch the video as a homegrown month-old squash gets squashed! Who said the DPRG only made robots?

More about the DPRG

Related:

Our final main event for MAKEcation 2009 is our "Family Challenge," as in the Hatfields vs. the McCoys, the Lancasters vs. the Yorks, the Macs vs. the PCs. Build a backyard trebuchet! The family that builds our favorite, and sends us the documentation, will get a $100 gift certificate from the Maker Shed. Five runners up will get a Maker's Notebook and their choice of The Best of MAKE or The Best of Instructables.