World Maker Faire 2013: The Sub-$500 Deltaprintr

September 22, 2013 by 30 Comments

There are a few delta bot 3D printers out there such as the Rostock which, while being a very nice printer, is still a little expensive. When [Shai] from SUNY wanted to use a 3D printer for his artistic and academic pursuits, he decided to build his own printer. Thus the Deltaprintr was born.

Instead of printed parts, the Deltaprintr uses laser cut and machined parts for just about all of its bill of materials. The three motors mounted in the base are connected to the delta arms with Spectra fishing line, thus getting rid of the ludicrous cost of belts of the requisite length.

Everything is Open Source, and the guys behind the project should be putting their printr up on Kickstarter sometime next month. Word is the entire thing should be sub-$500, and a little bit of guessing tells me that doesn’t mean $499.

Trash To Treasure Bluetooth Radio And Tube Amp Build

September 22, 2013 by 8 Comments

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The before image doesn’t look all that bad but we were still impressed with what went into the restoration of this radio. Perhaps restoration isn’t the right word since it didn’t manage to hold on to any of the original internals. This is more resurrection of a retro radio case for use as a Bluetooth radio.

At first look we didn’t notice that the original knobs were missing. The speaker fabric is ripped and the glass on the tuning dial is broken as well. [Yaaaam] happened to have another antique radio with interesting knobs — but he didn’t just transplant them. He made a mold of one knob and cast three replacements for the radio. After refinishing the wood he replaced the fabric and things were really starting to look up.

All of the electronic components were removed and a new tube amp was built on the original metal chassis. It uses a Bluetooth module for input which facilitates using your smart phone as the playback device without involving any wires or other nonsense. Two problems popped up after the project was completed. The first replacement power supply overheated. The second replacement had a different problem, needing some additional shielding to prevent noise from creating unwanted… noise.

This looks so much better than modern injection molded plastic shelf systems. But there are some fun wireless hacks out there for those too.

A $100 Stereolithography 3D Printer

September 22, 2013 by 103 Comments

The Hackaday tip line has been blowing up with a new Kickstarter for a 3D printer. Although this is a pretty common occurrence around here, this printer is actually very interesting: it’s quite possibly the simplest and cheapest laser resin printer ever.

Most of the 3D resin printers we’ve seen, like the Form1 use mechanical means to raise a print up to the next slice. At $100, the Peachy printer doesn’t have the budget for such luxuries as servos or motors, so the layer height is increased by dripping salt water over the liquid resin. The X and Y axes are controlled with mirrors and voice coils, allowing this printer’s electronics to be controlled by a computer’s sound card. It’s really amazing in its simplicity, and from the looks of it the Peachy can produce some fairly good prints.

For a great explanation of how the Peachy printer works, you can check out the video below.

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An “ill” Logical PWM Control

September 22, 2013 by 12 Comments

illogicalPWMcontrol

[James] recently finished up a gigantic seven segment display for Nottingham Hackerspace, and although it looks great, the display isn’t the interesting part. The PWM dimmer control implemented in logic is the true head-turner. That’s right: this is done without a programmable controller.

Unsatisfied with the lack of difficulty he faced when slapping together the rest of the electronics, [James] was determined to complicate the auto-dimmer by foregoing all sensible routes. He started by building an 8-bit timer made from a 555 timer fed into a 12-bit 4040 counter. He then used an 8-bit ADC IC to read a photoresistor. The outputs from both the ADC and from the scratch-built 8-bit timer plug into an 8-bit comparator; If the values match, the comparator outputs LOW for a single clock period.

Though this set the groundwork for PWM control, [James] had to add a couple of additional logic gates into the mix to nail everything down. You can find a diagram and the details behind flip-flopping out a duty cycle on his project blog. Clever builds like this one are a rarity when a few lines of code and a microcontroller can give you numerous shortcuts. [James] doesn’t recommend that you over-engineer your PWM controller, but we’re glad he did.  Meanwhile, Moore’s Law marches on; check out what people are doing with Low-Energy Bluetooth these days.

ContactKey: A Portable, Battery-powered Phonebook

September 22, 2013 by 5 Comments

contactKey

Although it’s still a prototype, [Russell] tipped us off to his battery-powered device for storing your contacts list: ContactKey. (Warning: Loud sound @ beginning). Sure, paper can back up your contact information, but paper isn’t nearly as cool to show off, nor can it receive updates directly from your Android. The ContactKey displays a contact’s information on an OLED screen, which you can pluck through by pressing a few buttons: either ‘Up,’ ‘Down,’ or ‘Reset’. Although the up/down button can advance one contact at a time, holding one down will fly through the list at lightning speed. A few seconds of inactivity causes a timeout and puts the ContactKey to sleep to conserve battery life.

This build uses an ATMega328 microcontroller and an external EEPROM to store the actual list. [Russell] wrote an Android app that will sync your contact list to the ContactKey over USB via an FTDI chip. The microcontroller uses I2C to talk to the EEPROM, while an OLED display interfaces to the ATMega through SPI. We’re looking forward to seeing how compact [Russell] can make the ContactKey once it’s off the breadboard; the battery life for most smartphones isn’t particularly stellar. Phones of the future will eventually live longer, but we bet it won’t be this one.

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Talkbot: An Arduino-driven Robot For Beginners

September 21, 2013 by 5 Comments

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It isn’t exactly WALL-E, but [Bithead’s] affordable introduction to robots — Talkbot — is made out of a trash can. This little guy runs off an Arduino and comes packed with features, including a voice chip, a motor shield, and a pair of bump sensors. Talkbot will cruise around until a bump sensor slams into an obstacle. One of his prerecorded messages will then play through the speaker while he backs up, turns, and tries to find a clearer path.

According to [Bithead’s] build log, tracking down the right bargain voice chip was a bit of a hassle; he skipped over the text-to-speech options only to be stalled by vendor issues. He finally settled on a clone of Sparkfun’s WTV020SD chip sourced from eBay, which allows you to access pre-recorded WAV files stored on a Micro-SD card. The robot’s body comes straight off the hardware store shelf, with PVC pipe for arms and a polystyrene base to hold all the parts.  At the bargain price of $110, [Bithead’s] students will have a true hacker experience cobbling the Talkbot together rather than using a prefab kit.

Be sure to see Talkbot  in a video below, performing either his green-eyed “friendly mode” or red-eyed “grumpy mode,” which dictates how pleasantly he responds to obstacles. Need something more advanced? Check out the tentacle robot, just in time for Halloween.

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VCR Centrifuge

September 21, 2013 by 33 Comments

VCR’s practically scream “tear me open!” with all those shiny, moving parts and a minimal risk that you’re going to damage a piece of equipment that someone actually cares about. Once you’ve broken in, why not hack it into a centrifuge like [Kymyst]? Separating water from the denser stuff doesn’t require lab-grade equipment. As [Kymyst] explains: you can get a force of 10 G just spinning something around your head. By harvesting some belt drives from a few VCR’s, however, he built this safer, arm-preserving motor-driven device.

[Kymst] dissected the video head rotor and cassette motor drive down to a bare minimum of parts which were reassembled in a stack. A bored-out old CD was attached beneath the rotor while a large plastic bowl was bolted onto the CD. The bowl–here a microwave cooking cover–acts as a protective barrier against the tubes spinning inside. The tube carriers consist of plastic irrigation tubing fitted with a homemade trunnion, which [Kymyst] fashioned from some self-tapping screws and a piece of PVC. At 250 rpm, this centrifuge reaches around 6 G and best of all, gives a VCR something to do again. Take a look at his guide and make your own, particularly if your hackerspace has a bio lab.