Skip to main content

Posts

Showing posts from 2014

Making a Circle Jig

     Have you ever needed to cut a circle? Turns out you can't just freehand that. If you want to cut a circle you need a.... Circle Jig! This handy little thing straps onto a standard router. You stick a pin in one of the little holes for the center, strap a router to the other side and route yourself a circle. Here's a commercial circle jig. Seems simple enough. Now what if you want this thing -Right Now-? Well then you better have a Laser Cutter and some Acrylic. Step 1 of the design comes from measuring out the dimensions of the existing router plate. What are those curved holes for? Who knows? But they look cool right? Starting from a base circle of diameter 1/4 in (size of the router bit) we offset another circle at some whole number of mm to mark the smallest radius we can cut. Then we offset a whole bunch of other circles in 2mm increments. Then add some horizontal lines. We want to place the center holes at intersections of the horizontal lines and ci

Building an enclosure for the LulzBot AO 100

As the cold weather season arrives in Atlanta, with it comes issues with our 3D printers. Specifically problems with temperatures and print stability. Freeside is essentially a big warehouse, and our 3D printing station is setup in the large open area in the front of the space. What this means is that when it is cold in the space, this will affect the printing quality because the ambient temperature is far lower than what is optimal for thermoplastics. The cold ambient air will cause parts to rapidly cool during the middle of a print. And with materials like ABS which can shrink dramatically during cooling, this causes prints to warp, deform, and delaminate during and after printing is finished. The print on the left is showing signs of delamination from plastic cooling mid print. To remedy this, we built an acrylic enclosure for our LulzBot AO-100, which is our dedicated ABS printer. We tested the proof of concept of whether an enclosure would help mitigate printing problem

Using gaze-tracking to map how surgeons look at diagnostic images

A few years ago, a Freeside collaboration resulted in some published medical research on using 3D Printing in pre-surgery planning . In our second collaboration, we used gaze tracking to gather data on how surgeons with different levels of experience look at radiographs when diagnosing hallux valgus deformities. The new paper got published in the current issue of the Journal of Foot and Ankle Surgery . Interestingly enough, we actually came up with the concept for this project during a meetup about interactive art installations. The idea of eye tracking came up and we discussed what we could discover with the technology. So we started to try to figure out how to a study with the free and open-source tools available. We ended up needing: A webcam to look at the user's eyes. ITU Gaze Tracker to calibrate and interpret that data. (However, their website is now down, so I'm not sure how viable this is as part of the toolchain now.) OGAMA - Open Gaze and Mouse Analysis

Build-Out Recap!

A bunch of great stuff got done at the build-out yesterday. A huge thanks to everyone that came out to pitch in! Here are some pictures to recap the projects... Randy's team hung the curtain to the workshop to create more of a barrier between the front of the house and back of the house and to control dust levels a bit more. We'll be finishing the top of the wall soon, but the hard part's already done. Karen, Donald, Tom, Violet, and James framed the doorway to the Media Lab and Bio Lab and hung the door for that area. Next step is AC! Michelle and Mary's team cleaned out project storage and moved the shelves over so that Neils could put the flammability cabinets in that area. That allowed all of us with the help of Adam and Nathan to clean up the workshop and really tidy up. They also sorted out all of the laser cutter raw materials and cut them down to a usable size on the table saw.  For the portal clouds, JW, Nathan, and Kat rolled an aw

Motobrain: Interesting Investigation Concludes

I've had a problem with the way Motobrain calculated current flows for quite some time. Basically it always read a little higher than I expected it to if the textbooks are to be believed. Furthermore, one half the board always read a about 10% higher than the other half. It is not very unexpected that the "textbook" calculation and real life are a bit out of sync. Still, I wanted to know why the error was inconsistent between the two halves of the unit. That part was a bit unusual. Normally, the way you go about solving an issue like this is to exclude stuff until the problem is gone. First, I excluded the Power board, the PCB with all the high current flow, heavy copper, and power transistors (shown right). I did this using the test jig (right, below) I designed to test all the Motobrains that come out of the factory. The MCU board (the board with the sensors, microcontroller, and Bluetooth radio) plugs into the jig and is given a series of test signals to confi

Props and costuming - Building an Ultron helmet

Hello, Freeside readers, and welcome to my first blog post! My name is Michelle Sleeper, I am a prop and costume builder in Atlanta, working primarily out of Freeside's space. I have been building costumes and plastic space guns since 2001, and have been a member of Freeside since 2013. My most recent major project was to upgrade a costume I built last year of the Marvel comic's character, Ultron. The costume owner wanted a new and improved helmet, made of cast resin and full of all sorts of lights. It was a big and ambitious project, and I was very excited to get started. Here's how we got there. From the outset we decided that we wanted the master sculpt to be 3D printed - but for those of you familiar with 3D printing, you know that extremely large prints are difficult if not impossible to produce. Most often, you will have to break your model up into many different segments, which you then assemble like a 3D jigsaw puzzle. We opted not to do that, and ins