For quite some time now we’ve seen people casting their own countertops and other surfaces out of cement. It’s a combination of mold-making and surface finishing that produces a smooth and durable surface at quite a low cost, if you don’t factor in damage done to your back when lifting the thing for installation.
This offering is a little bit different. [Elliott Spelman] built his own touch sensitive cement table top. When you place your grubby hands on the polished surface, a loop of neon lighting is switched on. This is thanks to a 4:1 mix of quick setting cement and iron oxide powder. Bare copper wire was laid around the edges of the surface to be encased by the cement for making connections later.
There were some sad moments when [Elliott] was removing the cast surface from the mold. He ended up cracking it and suggests others be liberal with their use of both wax on the mold before casting, and patience in removing the cement afterward. We might also suggest a strengthening agent like fiber reinforcement. The edges and surface can be sanded to the finish desired and in this case, attaching table legs was easy since the wooden underside of the mold remains on the bottom of the cement.
The neon lighting adds a retro touch to this build. It’s sad to see this technology dying away, so a resurgence of artisanal neon is great in our book. [Elliott] found a Bay Area arts collective called the Crucible which does a lot of art glass education to help him make two hoops of glass tube and fill them with the appropriate gasses. A capacitive touch sensor (once Atmel, now Microchip part) AT42QT2120 (datasheet) monitors the wire coming from the slab and switches the power supply for the tubes using a combination of relay board and Arduino Uno.
We find the prospect of positional sensing in doped cement fascinating. Anyone have ideas for adapting this technique so that a more long and narrow slab could have positional awareness within, say, a few inches? Let us know in the comments.
Continue reading “Touch Sensitive Cement with Just a Dash of Neon”
One of the worst things about your average modern keyboards is that they have a tendency to slide around on the desk. And why wouldn’t they? They’re just membrane keyboards encased in cheap, thin plastic. Good for portability, bad for actually typing once you get wherever you’re going.
When [ipee9932cd] last built a keyboard, finding the right case was crucial. And it never happened. [ipee9932cd] did what any of us would do and made a custom case out of the heaviest, most widely available casting material: concrete.
To start, [ipee9932cd] made a form out of melamine and poured 12 pounds of concrete over a foam rectangle that represents the keyboard. The edges of the form were caulked so that the case edges would come out round. Here’s the super clever part: adding a couple of LEGO blocks to make space for the USB cable and reset switch. After the concrete cured, it was sanded up to 20,000 grit and sealed to keep out sweat and Mountain Dew Code Red. We can’t imagine that it’s very comfortable to use, but it does look to be cool on the wrists. Check out the gallery after the break.
Concrete is quite the versatile building material. We’ve seen many applications for it from the turntable to the coffee table to the lathe.
Continue reading “Custom Keyboard Makes the Case for Concrete”
[Alex Le Roux] want to 3D print houses. Rather than all the trouble we go through now, the contractor would make a foundation, set-up the 3D printer, feed it concrete, and go to lunch.
It’s by no means the first concrete printer we’ve covered, but the progress he’s made is really interesting. It also doesn’t hurt that he’s claimed to make the first livable structure in the United States. We’re not qualified to verify that statement, maybe a reader can help out, but that’s pretty cool!
The printer is a very scaled gantry system. To avoid having an extremely heavy frame, the eventual design assumes that the concrete will be pumped up to the extruder; for now he is just shoveling it into a funnel as the printer needs it. The extruder appears to be auger based, pushing concrete out of a nozzle. The gantry contains the X and Z. It rides on rails pinned to the ground which function as the Y. This is a good solution that will jive well with most of the skills that construction workers already have.
Having a look inside the controls box we can see that it’s a RAMPS board with the step and direction outputs fed into larger stepper drivers, the laptop is even running pronterface. It seems like he is generating his STLs with Sketch-Up.
[Alex] is working on version three of his printer. He’s also looking for people who would like a small house printed. We assume it’s pretty hard to test the printer after you’ve filled your yard with tiny houses. If you’d like one get in touch with him via the email on his page. His next goal is to print a fully up to code house in Michigan. We’ll certainly be following [Alex]’s tumblr to see what kind of progress he makes next!
You need a coffee table, you need a dinner table. Do you really need two tables? [Shua] thinks the answer is “no”. That’s why he built this swinging countersink table out of concrete and a aluminum.
He started by making a simple half-scale prototype. Then a larger one. Through these explorations he learned how the table would be made, what kind of weight it needed, and how the mechanics needed to be constructed for the most stable table top.
Next he designed the final table in Autodesk Revit. This is software traditionally used for architecture. Since the table was to be made from concrete Revit’s useful set of concrete tools were useful for this project.
Most of the construction process was pretty standard. However, the use of CNC’d pink insulation as a mold for the concrete was interesting. The foam is closed cell, so it worked fine and gave a nice finish. The assembly was finished with a glass top and a carpeted base that contained a surge suppressor and two outlets. The table can be seen swinging between two positions in a video after the break.
Continue reading “Concrete Table Just the Way You Like It”
[amazingdiyprojects] has been working on a 3D printable jet engine. You may remember seeing a 3D printed jet engine grace our front page back in October. That one was beautiful didn’t function. This one flips those values around. [amazingdiyprojects] seems to make a living from selling plans for his projects, so naturally most of the details of the build are hidden from us. But from what we can see in the video clips there are some really interesting solutions here.
Some of the parts appear to be hand-formed sheet metal. Others are vitamins like bearings and an electric starter. We really liked the starter mechanism, pressing in the motor to engage with a spline, or perhaps by friction, to give the starting rotation.
What really caught our attention was casting the hot parts of the printer in refractory cement using a 3D printed mold. It reminds us of the concrete lathes from World War 1. We wonder what other things could be built using this method? Flame nozzles for a foundry? A concrete tea-kettle. It’s pretty cool.
We’re interested to see how the jet engine performs and how others will improve on the concept. Video of it in action after the break.
UPDATE: [amazingdiyprojects] posted a video of the engine being disassembled.
Continue reading “A 3D Printed Jet Engine Appears to Function”
Concrete – it’s all around you. You probably walk on it, drive on it, and maybe even sit on it! From a civil engineering standpoint, concrete really is a miracle material. But, it does have its downsides, especially in heavily developed urban areas. One of the most glaring of those downsides is the tendency for water to pool and flood on concrete. However, a new concrete formula could dramatically improve that by allowing water to drain quickly through the concrete itself.
While all unsealed concrete technically absorbs water, it does so very inefficiently and quickly becomes saturated. Once that happens, water will pool on the surface. This causes obvious problems for cars, as they become susceptible to hydroplaning. It also creates the potential for flooding in heavily paved areas.
This new concrete formula, called Topmix Permeable, is designed to reduce pooling by letting the water flow through at the rate of 600 liters per minute per square meter! It does this by using larger gravel pieces in the mix, which leaves bigger gaps for the water to drain down into. From there, it can be absorbed by the underlying soil, or routed safely away from roadways and parking lots.
Of course, this formula isn’t perfect. Its ability to pass through water also makes it likely to crack and quickly deteriorate in cold climates, as the water freezing and thawing inside the concrete will easily damage it. But, in warmer climates that receive a lot of rainfall in bursts, it could significantly improve safety.
Continue reading “Concrete With a Drinking Problem Could Reduce Flooding”
[Dan] had a bunch of concrete mixing to do. Sure, it was possible to stand there and mix concrete and water in a wheelbarrow for hours and hours but that sounds like a tedious task. Instead, [Dan] looked around the shop to see if he had parts available to make a concrete mixer. As you may have guessed, he did. Instead of stopping at just a concrete mixer, he decided to make a concrete mixing wheelbarrow!
The frame is built out of plywood left over from a past canoe project. The frame holds a mixing barrel that was also hanging around the shop. From the photo, the drive system looks simple but it is not. First, the small motor pulley spins a larger pulley that is in-line with the barrel. Gearing down the drive this way increases torque available to spin the barrel, and that gear reduction is necessary to spin the heavy concrete slowly. What you can’t see is a planetary gear system that gears down the drive train again. The gears are cut out of plywood and were designed in this Gear Generator program. The sun (center) gear of the planetary setup is supported by another scavenged part, a wheel bearing from a Chevy minivan.
Now [Dan] can mix all the concrete he wants, wheel it over and dump it wherever he needs it. With the exception of the drive belt and some miscellaneous hardware, all the parts were recycled.