Over in the labs at Ohio State University, a new method of embedding multiple similar antennas into clothing can actually help cut down on signal loss.

While this is not the first time that clothing has been used to send and receive radio signals, the OSU technology is unique in that it uses a computer control device to facilitate several antennas within one piece of fabric.

Because the body’s position may result in one or more of the antennas being blocked by obstacles, or short-circuited against the wearer’s skin, the controller is able to switch between antennas so that the one best able to transmit and receive is activated. In lab tests, the vest was found to be able to work in all directions, offering four times the range of a standard military whip antenna.

While current tests involve flexible film antennas sewn into the clothing, the researchers are also looking at directly printing the antennas on the clothing as well.  And while military applications may seem most obvious, there is also the opportunity to use this technology for the elderly and disabled as well by allowing communication in emergencies.

(via Slashdot)

Over in the forum, we’re designing a software-defined radio modeled after Jeri Ellsworth’s Hackaday post from earlier in the summer.  We ordered PCBs for the first revision perhaps a bit too hastily, as some forum members with valuable experience in the area found a number of shortcomings in our design.  Those have been corrected (we hope!) with this latest round of updates.

Changes that have been made include moving to a better oscillator module (wider frequency range, better stability, less phase noise) and to an external 24-bit ADC (for higher dynamic range).  We have a few boards of the old design already fabbed, but things like work and school keep getting in the way of building up a prototype or two to start coding.

Check out the schematic and layout over on github (or just grab the latest NBitWonder Eagle Library update), and let us know what you think in the forum!  We might not always respond right away, but we value your input.

Big news over at Dangerous Prototypes as they successfully release their open source USB stack today. Via Dangerous Prototypes:

Good news everyone! A new free and open source USB stack is now available for PIC microcontrollers. Today we finished testing and prepared a simple echo test that works with PIC 18F and 24F. We hope a demo release will get more developers involved. A release package and overview are in the forum. As always, thanks to Honken and JTR for making this possible.

Microchip has a free-as-in-beer USB firmware for the PIC microcontroller, but it can’t be redistributed. For a project like the USB IR Toy, we can give you our source code but not the USB source. You have to get that on your own from Microchip. It’s not a huge problem, but it is a barrier for people new to PICs. We used the Microchip firmware because it works great and there wasn’t an alternative.

This looks exciting, and we can’t wait to see what people do with this!

This is the ninth post in a blog series detailing my efforts to construct a RepRap Mendel, an open-source 3D printer. For the rest of the blog series, see here.

Introduction:

Previously, the Mendel blocks were constructed and everything was put together. Then came the lengthy process of machine calibration. I was closing in on a successful first test print, and victory looked assured.

During machine calibration, I tried to fix an axis issue using the “latest” firmware from Mendel-parts, only to be mortified as the latest firmware proved to be completely non-functional. Desperate to make things work, I switched to the Sprinter alternative firmware and Printrun software toolsuite. The extruder heated up and turned, the stepper motors moved, we were ready to try a test print!

I took some 3mm ABS plastic and fed it into the extruder. In pronterface, there are a number of pre-defined temperature settings, one of which is 230 celsius for ABS plastic. I dialed that on and watched the temperature rise…

Craaaaaaaaaaaap:

And looked on in horror as the temperature sky-rocketed well past 230 celsius all the way to 265 degrees celsius. That’s right, the PID control system was so poor that a 35-degree temperature overshoot was deemed acceptable. The funny thing is, at 265 celsius ABS plastic starts to burn. The plastic in the nozzle carbonized into a hardened, unmeltable substance, completely jamming the hotend.

Mendel is designed in such a way that successfully doing work on the hotend requires ripping apart the X-carriage block, a considerable work effort. Not wanting to do that, I attempted to save the hotend by forcefully clearing it. I started hand feeding plastic into the hotend, and watched as a paltry amount of blackened plastic came out the end. Things looked like they were working, until plastic forced its way through the hotend’s kapton insulation. Craaaaaaaaaaaap.

I shut down the machine, and, when cool, pulled the X-carriage block off the X-axis and disassembled, granting me access to the extruder. As I had hypothesized, the hotend was “shot”. Hardened, unmeltable plastic everywhere, and it had forced its way through the screw threadings in the hotend, locking the parts together very thoroughly. Attempting to unscrew the nozzle with a pair of pliers, I broke the nozzle in half. It was official, I was going to need to buy a new nozzle. Craaaaaaaaaaaap.

Replacement Hotend:

I went back to Mendel-parts (not by choice, but only because they had the only hotend I could absolutely guarantee would work in my machine), and ordered a replacement hotend. Mendel-parts, who continues to charm me with their lack of customer service, wooed me further by requiring a 25 euro minimum order and charging flat 25 euro shipping. Still, they will send you your stuff if you give them your money, so I had a replacement hotend roughly a week later. An extruder test, thermal overshoot test, and some reassembly later, and I was back in business!

The Reprap build is ongoing, but in the meantime, be sure to check out our flickr set for the latest build photos!

More exciting news today, NBitWonder will be exhibiting at Maker Faire Fort Wayne on October 1st and 2nd at the Lincoln Pavilion in Headwaters Park East. From the event website:

Organized by TekVenture, tekventure.org, the Fort Wayne Regional Maker Faire™ in partnership with MAKE Magazine is a unique fair that brings together science, art, craft and engineering plus music in a fun, energized, and exciting public forum. The goal of MAKE’s publisher, O’Reilly Media in creating the Maker Faire™ concept is to inspire people of all ages to roll up their sleeves and become makers. This family-friendly event showcases the amazing work of all kinds of makers – anyone who is embraces the DIY spirit and wants to share their accomplishments with an appreciative audience.

Tickets are available now, so consider purchasing one and attending. We hope to see many of you there!

Striking a design similarity to a Star Wars Droideka battle droid, the MorpHex is a rather remarkable project.  While at first glance it might be considered an ordinary hexapod, it has a handful of several very interesting design ideas going to work.  For starters, the MorpHex has a dynamic support structure which can expand and contract to give the legs a variable walking radius.  From the core support, MorpHex uses 31 servos in a mirrored hexapod style to create a machine capable of creating a ball.  Couple that with the attachment of several exterior spherical shell pieces, and you have yourself a very unique rolling hexapod.  One thing that cannot  go unnoticed is the quality of the control software for this robot creating incredibly smooth transitions and walking strides.  Be sure to also check out all the beautiful photos on Zanta’s project page for a better idea of how the MorpHex functions.  Strap on a few blaster cannons and the MorpHex should be the perfect candidate for protecting your empire.

(via Hack a Day)

IEEE Spectrum has an article detailing a pair of innovative, off the beaten path UAV designs that are cool and very interesting to watch in action.

First up is the Lockheed Martin Samurai UAV. Based on the design of a maple seed, the robot achieves lift by spinning around in circles very quickly. The result is a simple, durable UAV, without the need for many of the fragile parts in helicopter rotors and traditional aircraft ailerons, etc. A video of this thing in flight is shown below:

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The RepRap Mendel saga is a series detailing my efforts to build a RepRap Mendel, an open source 3D printer. For the rest of the posts detailing the project build, see here.

In addition to photographing the Mendel as I built it, I set up my cameras and let them roll throughout much of the build (8 hours of footage in total). I compiled the Mendel build footage into a time-lapse video for you to enjoy.

Check it out! Additionally, don’t forget to see high quality build photos of the Mendel in our flickr set!

Over in the forums, we’re working on improving our project documentation templates. We released a set of LaTeX documentation templates some time back in February, which we have been using to document projects over the last 6 months. However, LaTeX is somewhat inconvenient to edit and has a steep learning curve. As such, we’re pleased to announce development of a new set of documentation templates in Open Office 3.

The switch to Open Office means we now have macro functionality, which is largely absent in LaTeX. It is now possible to write intelligent BOM templates, incorporate logged test results directly into reports, and much much more. We’re looking for good script ideas to make documentation easier and better, so if you have any, pop over to the forums and post em up!

This is the eighth post in an ongoing series about my attempts to construct a RepRap Mendel, an open source 3D printer. For more posts on the RepRap Mendel, see here.

Introduction

After a considerable amount of effort, I successfully built all of the blocks, tested the individual components, and put everything together.

Between the victory lap for actually having everything assembled and successfully printing objects comes the process of calibration and test. This ended up being a somewhat lengthy process with many different steps.

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