Hackaday Links: August 15, 2012

August 15, 2012 by 9 Comments

An Octopart for RC equipment

When [Zach] started building a quadcopter he found it very difficult to source the required parts. Thus was born CompareRC, an aggregation of several online RC retailers. There’s over 150,000 parts in the database, all searchable and sortable by lowest price.

Segway iPad Skype teleconferencing robot

It’ll be a while until robots completely eliminate the need for any human interaction, but until then there’s Double. It’s a two-wheeled balancing robot with an iPad dock, controllable via a remote iPad.

Free electronic design

In case you weren’t aware, Fedora has an electronic design distro that includes just about everything needed to build electronic circuits called Fedora Electronic Lab. FEL has PCB designers, circuit simulators, editors for just about everything, and support for PICs, AVRs, and 8051 micros. Thanks for sending this in, [Simon].

Make your own Megadrive ROMs

Last month, [Lee] sent in a build where he connected an Arduino Mega to an old Sega Genesis/Megadrive cartridge. He’s figured out how to read the contents of the cartridge now, allowing you to preserve your 100% complete Sonic & Knuckles / Sonic 3 save for time immemorial.

A surprising amount of graphics tutorials

Khan Academy, every autodidacts best friend, is now teaching computer science. Right now, there is a heavy focus on drawing graphics, and everything is coded in the browser (using Javascript…), but at least it’s a start. The fundamentals of programming are platform and language agnostic, so this looks to be a great way to learn programming.

Here’s a blog post from the lead dev of the Khan CS project.

3D Printed AR-15 Lower Works

July 26, 2012 by 82 Comments

Ar15.com user [HaveBlue] has been working for some time on a 3D printed lower receiver, and now reports that the parts are fully working. Using a Stratasys 3D printer from the 90’s [HaveBlue] managed to spin out a modified version of an already available model from cncguns.com. He strengthened the holes for the takedown lugs, which hold the upper and lower halves of the rifle together. Strengthened the bolt hold lugs, which when the magazine is empty lifts a lever assembly that catches the bolt as it springs back to push another round into the chamber. and added an integral trigger guard AKA the bar that surrounds the trigger.

Legally this print is a veritable gauntlet of state and federal regulations. At least in the US. The lower receiver is the part of the rifle that holds the spring and pins that operate the rifle’s trigger safety and hammer assembly, hold the magazine in place,  and mount the buttstock/return spring tube. The other key point about the lower receiver is that it contains the primary traceable identification markings, the serial number. All of the parts that are contained within the lower receiver can be ordered online (this varies state to state). In fact, every single other part of the rifle can be bought and sold freely. The only component of the rifle that can not be ordered online, and requires a background check at a gun store, is the body of the lower receiver (we have to keep saying that this varies state to state). Typically laws allow though for the manufacture of this part without a serial number so long as it is never sold to another individual (again, state laws vary widely).

There is some more info on the build at [HaveBlue]’s website here and here, but it is currently down.  This sort of steps up 3D printing past the nerf gun stage, but we have seen shot gun and pistol hacks.

Two-stage Rocket Climbs To 15 Km, Promptly Gets Lost

July 11, 2012 by 34 Comments

Last month, the Cambridge University Spaceflight society launched two stages of their Martlet 1 three-stage rocket. After seeing our call for rocket builds, they sent in a launch report. We’re glad they did; it’s an amazing piece of work that screams into the atmosphere faster than the speed of sound.

The society is designed the three-stage Martlet 1 with the goal of reaching 15km (50,000 feet) over a launch range at Ben Armine in Scotland. This launch was a test of stage separation, intended to work out any bugs in the system before going to the full-sized rocket.

When Martlet 1 takes off, it’s 1st stage engine fires for 5 seconds and coasts for another 9 seconds. In the video after the break, the guys expected to hear the pop of the second stage igniting after 14 seconds. The team forgot to account for the fact the rocket would be 3km in the air at that time, and thanks to the slowness of sound the second stage was heard though the clouds at 25 seconds after launch.

With rockets, hardly anything goes exactly as planned, so unfortunately the team only recovered the bottom half of their rocket. After searching over 60 square km for the second stage, the guys realized it might be lost to the moors of Scotland. Hopefully the second stage will turn up soon so the full 3 stage stack can be realized.

Check out the launch videos after the break.

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$15 Toy Becomes Fully Programmable Robot

February 28, 2012 by 8 Comments

[Kevin] undertook a robot build partly for his own enjoyment, but also to include his kids in the action. He acquired a cheap toy and packed it full of programmable goodness. The starting point was a $15 toy called Rad 2.0. It’s a great starting point as it already included some motorized parts, and takes care of much of the mechanical issues like joints and structure.

The image on the left is the fourth update which [Kevin] has posted. The robot now responds to voice commands (with the same syntax as Chippu uses), moving its gaze to face forward or to either side. You’ll notice there’s a wireless webcam which lets him spy on what’s in front of the robot’s gaze. An ultrasonic range finder makes itself at home in the beak of the bot, and a Larson Scanner is nestled in the brow using the kit from Evil Mad Scientist Labs. Check out the video after the break for an overview of the hardware modifications.

The build log for this project is a forum post. That forum is run by [DJ Sures], a veteran at taking cheap toys and making them awesome. It seems like he’s taken a web forum and made it awesome too because the conversation about [Kevin’s] project is packed with constructive tips and encouragement.

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$150 CNC Mill Is A Tad Slow But Very Solid

November 11, 2011 by 19 Comments

diy-150-cnc-mill

Like just about everyone else out there, [Adam] thinks that CNC machines are pretty cool – so cool that he decided to build one of his own from scratch.

The CNC machine was constructed mostly out of MDF and scrap wood, with drawer slides used for smooth gantry movement. An off-brand rotary tool was used to do the actual cutting, and [Adam] picked up a few Sparkfun stepper motors to drive the machine.

The assembly was completed without too much trouble, but [Adam] says that programming the mill was a long and frustrating process. Cutting was rough and not very accurate at first, but little by little he got things working pretty well. As you can see in the video below, while the cuts look great, improvement came at the expense of speed. He says that the machine could use a redesign to speed it up, which he’ll get around to if some free time comes his way.

It’s not the absolute cheapest CNC build we’ve seen, it’s pretty darn close. With a few tweaks, it could definitely be a solid budget-friendly contender.

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Baking An HP LaserJet 1522 Series Back To Life

October 19, 2011 by 51 Comments

resurrecting_hp_laserjet

[Thice] had himself a problem. As luck would have it his HP laser printer died shortly after the warranty period expired, and HP was ready to charge him €350 to repair it. Since that would pretty much buy [Thice] a new one, he decided to try fixing the problem himself. He scoured the Internet for a solution to his problem, and luckily discovered that his printer might be recoverable.

The entire LaserJet M1522 series is apparently pretty prone to breaking, with the formatter board being the usual point of failure. To fix his printer, he disassembled the outer shell, removing the formatter board from the unit. Once the onboard battery was removed, he constructed a set of standoffs using aluminum foil, and set the board in his oven at 180°C (~356°F) for about eight minutes.

After cooling, he reinstalled the board, and his printer behaved as good as new. [Thice] says that the only problem with his fix is that he needs to bake the board every 6 months or so, making this a great hack but not the most ideal solution in the long term.

Join The Pen15 Club With A Vibrator Shield

October 16, 2011 by 88 Comments

For all you teledildonics enthusiasts, there’s a new Vibrator shield for the Arduino. It gets better: you can use the Pen15 shield with a Kinect for wholesome and natural fun at home.

Decency and a ‘safe for work’ style prevents us from putting everything we know on the front page, so keep reading after the break.

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