Full-size MRI Machine Replica

November 9, 2013 by James Hobson 15 Comments

Foam MRI machine

It’s been a bit dusty lately in Seattle’s Metrix Create:Space. That’s because they’ve taken on their biggest project yet — a full scale replica of an MRI machine for university research.

[Tom Grabowski], a professor of Radiology & Neurology at the University of Washington, needed a replica MRI machine. This is because time on real MRI machines is very expensive, and when performing research on Autism, it is important to get the test subjects used to the process before using the real deal. He originally turned to the Center for Human Development and Disability, also at the University of Washington, but the project was just simply too big for their facilities. He did however get to meet a fellow researcher named [Fritz] who then contacted Metrix to see if it was possible, and like any good hackers, the members of the space were more than up for the challenge.

The replica MRI machine is made out 2″ thick, 4′ by 8′ foam insulation sheets, which is the maximum size their router can handle. Not having made use of the 3D z-cutting capabilities before, they had a bit of learning to do, but as you can see from the pictures, it worked out quite well. Over a few weeks they were able to construct the general shape of the MRI machine, and finish the surface nicely — it’s far from complete though, as they might even be adding lights and other features to make it one heck of a replica. It’s a great project, and those who have helped are happy to do so as the replica will benefit not only [Tom] but many other researchers at UW — for science, yeah!

3D Printed Velcro

November 8, 2013 by Brian Benchoff 2 Comments

Velcro

With new materials comes new possibilities in fabrication, and with 3D printers, this observation is no different. In the past year or so, there have been a few very interesting new filaments that have come into mainstream use – a printable sandstone, high impact polystyrene, and a flexible PLA. When [Rich] saw a bike light that had an integrated hook-and-loop fastener – think Velcro – built in to its enclosure, he thought to himself, ‘I could do that too.’

[Rich]’s “ElastoStraps” are printed with Makergeek’s Flexible PLA, and the entire device works surprisingly similar to other hook and loop fasteners with a registered trademark. The design is up on Thingiverse, and since the object was designed with OpenSCAD, the 3D printed Velcro can also be opened up in the Customizer for hook-and-loop straps that perfectly suit your needs.

Freeside’s Infinity Portal

November 8, 2013 by Marsh 11 Comments

sidebyside

If infinity mirrors aren’t cool enough, the 10-foot-tall infinity portal should blow you away. Strictly speaking, the mirror itself is only 7’x4′, but you’ll still find yourself engulfed in the archway. The portal began as a simple prototype that we covered earlier this summer, which was just a frame of 2×4’s, some acrylic and LED strips. It works by putting lights between a two-way mirror and another mirror, reflecting most light internally and creating the illusion of depth.

The giant archway also began as a small-scale prototype, its shape and engravings carved out by a laser cutter. Once they were satisfied with its design, it was time to scale things up. The full-sized portal needed a a tremendous amount of stability, so the guys at Freeside built the base from wooden palettes. They needed the portal to travel to a few different venues, so the rest of the frame breaks down into components, including a removable wooden frame from which the acrylic hangs. A Teensy 3.0 runs all the WS2812 LED strips, which were chosen because each of their LEDs is individually addressable.

Check out the video below for an extremely detailed build log, which should give you a better idea of how massive and impressive this portal really is!

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RC Tractor Build

November 8, 2013 by James Hobson 18 Comments

[Rémi] is an engineer in France who runs his own little plasma cutting shop where he designs and manufactures custom projects for people. His latest project is this very slick remote controlled tractor.

It makes use of two 350W motors running at 24V, powered off of two 12V lead acid gel cells. The entire frame was designed in 3D CAD and then cut to shape using a plasma cutter. It was designed to tow small farm equipment around, or to turn mowing the lawn into a fun game that can be performed from the comforts of your lounge chair, while sipping a cold drink.

The reason we’re sharing this is because [Rémi] made an excellent video of fabrication and build of this project — So stick around after the break and enjoy! But be warned, watching the video may induce certain desires for owning a personal plasma cutter. Oh the possibilities!

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Trinket Contest Winners

November 8, 2013 by Mike Szczys 29 Comments

trinket-contest-winners

Originally Adafruit offered us 20 boards to give away. But when we had so many interesting submissions they were kind enough to throw in some more. We took them up on it, eventually choosing 41 winners… and believe us when we say it was difficult to whittle it down to that number! Thank you to all who took the time and made the effort to send something in.

Organizationally it’s been a challenge keeping all of the submissions straight. That’s why the presentation of the top entries is listed as a set of galleries. More info on each is available on their associated update posts. Congratulations to all! We want to do more giveaways in this same spirit (with different prize hardware and submission themes each time). If you’re interested in that please let us leave your words of encouragement in the comments.

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Tricking A USB Power Supply

November 8, 2013 by James Hobson 31 Comments

battery_load_pulser6

[Paul] recently purchased an inexpensive USB power pack, hoping to use it for powering small electronics projects. Unfortunately it has been designed to only stay on when a device is drawing a lot of power (like charging a cell phone), so he set out to fix it.

He started by experimenting to see just how much current is required to keep the battery pack on, and for how long. Testing a few resistors he discovered that a 22 ohm one will keep the power supply on indefinitely. If there’s no load, it only remains powered on for about 13 seconds. Now you can’t just hook up the 22 ohm resistor to a 5V power supply for the sake of keeping it on — that would draw 1.1watts and get very hot!

His next step was to determine how long the load needs to be on for, and at what interval in order to keep the power supply active. He created a test circuit using a Teensy microcontroller and determined that a 20ms pulse every 1.4 seconds was enough to keep it on — any less and it would switch off after a few minutes. The final transistor based circuit draws about 222mA — but at a 1.6% duty cycle, resulting in only a 3.5mA draw! [Paul] suspects the switching power supply inside battery pack probably draws more than that! He can’t take all the credit though, he learned of the idea from a forum post — but he certainly has made a very nice write up for people to follow in his footsteps!

Now that’s a good old fashioned product hack!

A New Old Lathe For Your Hackerspace Or Garage

November 8, 2013 by Jeremy Cook 51 Comments

3D printers, or even small CNC routers may seem like relatively easy machine tools to obtain for your hackerspace or garage. They are both very useful, but at some point you may want to start working with round parts (or convert square-ish items into round parts). For this, there is no better tool than a lathe. You can buy a small and relatively cheap lathe off of any number of distributors, but what if you were to get a good deal on a larger lathe? Where would you even start?

In my case, I was offered a lathe by a shop that no longer had a use for it. Weighing in at 800 pounds and using 3 phase power, this South Bend Lathe might have been obtained economically, but getting it running in my garage seemed like it would be a real challenge. It definitely was, but there are a few mistakes that I’ve made that hopefully you can avoid.

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