Many folks surely remember the days of fighting robots on TV: Battlebots, Robot Wars, Robotica, etc. And while its televised days are behind it, the sport is kept alive by groups of builders and competitors across the country. The Northeast Robotics Club (NERC) is just such a group, and one that I have been a member of since I first saw robots destroy and get destroyed on TV.
In the years since, I’ve traveled up and down the East Coast competing with robots of my own. But this past weekend, our own city of Philadelphia hosted NERC’s annual Franklin Cup, held in conjunction with the Franklin Institute. For this event I decided to continue the lineage of a long-standing family of NERC bots: ALF!
Now, this is the first robot I’ve built since I’ve moved to Philadelphia. My center-city apartment is about the size of a large phone booth and lacking any machine tools, so it’s obviously not a good workspace. The Hive, on the other hand, with its storage space, large work areas, and 24hr availability of tools and resources, was the perfect place to build. It may sound like a shameless plug, but the story of ALF would be incomplete without it.
I recently decided to make a proof-of-concept for a simple hydraulics kit. Ultimately you would be able to take this kit, get some standard PVC pipe from the local hardware store, and very quickly build your own simple hydraulic devices. Use it to learn about the principles of hydraulics while staying cool on a hot summer day, or use it to power your homemade tools like simple presses, lifts, or even an articulated digging arm.
Double-acting PVC hydraulic cylinder and control valve
The pressure in your typical garden hose is nominally around 40 psi or so, so my first hydraulic cylinder should be able to develop about 125 pounds of force if it had really good seals. This is a proof of concept so I didn’t bother with o-rings or anything, so it leaks like crazy and thus is unable to develop quite those kinds of pressures, although it is quite strong. Moving from a 2″ to a 3″ hydraulic cylinder would bring this up to about 282 pounds of force, not too shabby for garden hose power!
The hydraulic cylinder is made of standard PVC pipe (2″ for the cylinder and 1.5″ for the ram), although I had to use my lathe to turn down a 1.5″ pipe cap to fit inside the outer cylinder. The control valve is made of 1/2″ CPVC fittings and tubing, with the exception of the spool which is a length of 1/2″ solid PVC rod. I had to turn down the spool on my lathe to the appropriate profile and also had to drill out the valve to fit it. The fit is fairly poor but it shows that the concept definitely works. Eventually I am hoping to be able to have all the custom parts injection molded to get the unit cost down cheap enough that it would make a good toy for DIY doodlers and budding engineers everywhere.
This 5×6 LED tile is a key component in a secret project that I’m developing (in secret) with some other folks (whose names shall remain a secret).
Why be so public about something so secret? Because this tile uses a layout technique that lets you build charlie-plexed LED arrays quickly and cheaply — and that’s something worth sharing.
Charlie Tile Circuit
You need to flip the tile over in order to see what’s special about it. Here’s a quick list of features that make the assembly what it is:
The back of the tile has six “column” conductors and six “row” conductors.
These column and row conductors are connected along the diagonal of the row/column array. At all other points in the matrix, the row and column conductors are isolated via a layer of masking tape.
LEDs above the diagonal have their cathode connected to the conductive row immediately above the LED. LEDs on or below the diagonal have their cathode connected to the conductive row immediately below the LED.
All LEDs have their anode connected to the column that is to their immediate left.
The resulting circuit allows you to individually address any of the thirty LEDs in this 5×6 matrix using only six lines from a micro-controller. (more…)
One of our core members, Jordan Miller, has just published a scientific paper using RepRap 3D printing technology to engineer living tissues for regenerative medicine. I’ll give you a rundown of the science and a step-by-step guide of how Jordan got to this great spot in his career. Jordan is quick to point out that this is work that would not have been possible 5 years ago, or without the help of RepRap, Hive76, and this wonderful city of Philadelphia.
There are other labs around the world that are attempting what Jordan and the rest of the team at UPenn and MIT have been working towards. The end goal of regenerative medicine research is engineered tissues and replacement organs for treatment of human disease. As Science news says,
Imagine a world where if your heart or kidneys failed, you wouldn’t have to endure an agonizing, possibly futile wait for a donor whose organ your body might reject. Instead, a doctor would simply take cells from your own body and use them to “grow” you a new organ.
Other lines of research are attempting to 3D print directly with living cells and gel. These so-called “bioprinting” approaches involve loading cells and gel in syringes to be used as feedstock to create a structure from scratch. The problem is that healthy liver cells, for example, usually die of starvation (lack of nutrients) and suffocation (lack of oxygen) while enduring the slow 3D printing process.
Jordan’s 3D printed vasculature approach was inspired by whole organ vascular casts like this one.
Enter Jordan and his innovation: since vasculature provides the lifeblood to resident cells, why not focus on the vasculature first?
Jordan and the rest of the research team at UPenn and MIT have developed a new way to create vasculature for living tissues. This 4 step process involves: 1) 3D printing a network of sugar filaments, 2) surrounding it with living cells in a gel, 3) dissolving away the sugar to leave behind a vascular network for 4) the delivery of nutrients and oxygen. He accomplished this with a custom built 3D printer, extruder and control software.
Here’s a step-by-step of Jordan’s many year process:
Get a crazy idea to link sugar and vasculature when comparing the interior of a 3D print to a capillary network.
You can read the Penn press release about this awesome science, an overview from Science News, or the full paper. A more detailed post about the hardware used in this project will follow and soon you’ll be able to make your own sugar extruder. (It prints chocolate too!)
Humanities major and business guy here. Since joining Hive76, I’ve been blown away by how easy (and fun!) it is to make stuff yourself. But I also noticed that sourcing parts for projects you read about isn’t always that easy.
And – a lot of my friends here have great ideas for DIY kits, but they don’t want to take care of sourcing, shipping, collecting money, etc. Who can blame them? There’d be many more interesting kits out there if someone solved the sourcing problem.
That’s why I launched Kitify a few weeks ago. Kitify makes it easy to document and list a bill of materials for a DIY project (a little like Instructables, but you have control over the presentation), and with one click you can also sell your project as a kit that we put together for you. You tell us what’s needed to build the kit, we sell kits on your behalf, and you get paid.
Kitify was fun to build, I had to learn quite a lot to get it off the ground. Check it out! And if you’re interested in selling a kit, let us know through our contact form and we can either help you get it set up on Kitify, or give you other advice on marketing, logistics, design, and lots of other areas.
We got Matt Wettergreen’s MendelMax up and printing in two days. Thanks to all those at Hive76 who helped out with the build, especially Chris, PJ, Brendan, and Rob! Here’s a timelapse from the first day:
Below is a video of the finished bot printing with the latest Marlin firmware (smooth acceleration and fast travel times)! It turns out PLA sticks to a heated aluminum bed provided in the MendelMax kit. Wow. Completely Awesome. I couldn’t believe how little of the heat from the aluminum bed actually radiates away (you can only barely feel the heat an inch off the bed at 75 degrees celsius). That’s a huge feature.
For the second weekend in March, Hive76 is hosting a day of smashing, cutting, gluing, taping, painting, and general making and frivolity. We’re calling it “Art Hackathon”. Inspired by the Bravo TV Series Work of Art, and following closely in the footsteps of Art Hack Day, the event will focus on the rapid creation of meaningful works of art out of a provided supply of recycled materials.
Hive76 will provide massive piles of cardboard, tubs of glue, masking tape, tubs of spackle, box cutter blades, and a few cans of various colors of spray paint, to let every participating individual or team create a work of their choosing. The works will be based on a single theme, to be announced at the beginning of the event.
The event is split across two, four-hour days. While participants are free to use the time as they wish, the time is designed to provide time for planning on and a moderate amount of building on the first day, with some drying and curing time overnight before finishing up the next day.
A fee of $25 per person will be charged at the door, to cover the cost of materials and food that will be provided during the event for both days. Please RSVP for the event before March 6th by emailing firstname.lastname@example.org.
What is art? To me it has always meant indirect communication–the implied conveyance of ideas through conventions of shared culture. Anything is fair game for a medium, and anything can be a potential message; thus art is infinite in both dimensions. (more…)
P3D.in is a new beta service (currently free, prolly will change) for rendering 3D models in the web browser, no flash or plugins required. I guess it works via HTML5?
They only take .obj files at the moment (which you can export to from Blender). It’d be much much more useful if they automatically imported STL files, and all of Thingiverse, among other sites. I’ve logged a bug report and feature request along these lines.
Here’s a yoda head converted to .obj and imported and hosted by P3D in their demo iframe. pretty cool. (NOTE: I guess it needs a while to load in the browser, apparently. So if it’s not showing up yet in your browser, give it a minute).
Left click and drag – rotate
middle click and drag – zoom
Right click and drag – translate