Once upon a time, a woodworker met another woodworker who happened to have a tree business. They struck a deal stating that the first woodworker would dry the sawn boards provided by the second and both would share the lumber. That’s exactly what happened to [Tim], which led to his entry in The Hackaday Prize.
[Tim] does a great job explaining his build of the kiln itself, his controls, and the gist of running the thing. The idea is to pull moisture out of the wood at just the right speed. Otherwise, the boards might check on the outside, honeycomb on the inside, or bear residual tension. He’s using a dehumidifier to pump dry air into the kiln and a control system to both monitor the relative humidity in the kiln and to dry the stock down to a moisture content in the 6-8% range.
The kiln is built from slightly blemished pallet rack shelving that [Tim] cut to suit his needs. He skinned it with 1/2″ insulation boards sealed with aluminium tape and plans to add sheet metal to protect the insulation.
[Tim] wanted to control both a fan and the dehumidifier, monitor relative humidity in the kiln, log the data, and send it to the internets. For this, he has employed an Arduino Due, a DHT-22, an RTC, a relay board, an Ethernet shield, and an LCD to show what’s happening. The hardware is all working at this point, and the software is on its way. Check out his entry video below.
This project is an official entry to The Hackaday Prize that sadly didn’t make the quarterfinal selection. It’s still a great project, and worthy of a Hackaday post on its own.
Continue reading “Basement Wood-Drying Kiln”
[Richard]’s wife scored an Evenheat glass-fusing kiln, but the 20-year-old temperature controller was broken. He could have simply ordered a replacement controller, but that kind of problem solving doesn’t get you on Hack a Day. His wife wanted more control over the kiln and he convinced her that building their own was the way to go. Thus, the Meltinator 9000 was born.
[Richard]’s design uses an Arduino Uno and an Adafruit display shield, protoshield, and thermocouple reader board. He built a simple relay driver with a resistor, BJT, and a diode and connected it to pin 13 and its built-in indicator. To [Richard]’s delight, all of this fit in the original enclosure.
[Richard]’s software provides 25 fusing schedules with ten steps apiece. Each step has a target temperature, rate of temperature change, and a hold time which can be increased on the fly. He ran a test program that heated the kiln to 1500°F at a rate of 2550°F/hour. He then cooled it to 500°F at a rate of 1000°F/hour, which took longer than he thought. The good news is that the kiln is well-insulated! [Richard] has the software available on his GitHub.
Don’t have a glass kiln? Prefer to control beer-related temperatures? You could always hack your stove in the name of homebrewing.
A quick primer is in order: when it comes to hobby brewing there’s two main types, extract brewing and all-grain brewing. The former uses a syrup that has been extracted from the grains at a factory while the latter adds the steps to do this yourself. But in both cases the brewing grains have already been malted. This is a careful process of soaking the grains and then kiln drying them. [Richard Oliver] built his own malt kiln controller to add the preliminary step to his home brewing ritual. Now the only thing he’s not doing himself is growing the grains (and perhaps culturing the yeast).
His original design used a food dehydrator for the drying step, but this didn’t work because the temperature wasn’t at the correct level. The new build uses the ceramic heating element from a 300W hot air gun. A blower directs air through the element and into the wooden box that serves as the kiln. An Arduino monitors the heated air to keep it right in the sweet spot. He’s included a graphing GUI for easy monitoring, which is shown in the video after the break.
Continue reading “Malting kiln controller for preparing beer brewing grains”
[EmcySquare] is delving into some hobby-blacksmithing by making his own knives. He needs a furnace to heat the metal, and after trying out a few different forge designs he decided to attempt an electric kiln build. The final project seen above is a box within a box. The outer shell is reclaimed using old computer cases and metal shelving brackets. Inside you’ll find a box made from fire brick, with stone-wool insulation to keep the heat where it’s supposed to be.
He cut the bricks to the right size to build the inner box, then added grooves on the inside edge witch will host the heat coils. This cutting was done with an angle grinder and [EmcySquare] notes that it kicks up an extraordinary amount of brick dust to make sure you’re wearing a respirator and goggles. Once the enclosure was ready he set out to fabricate the heat coils. Twelve meters of Kanthal A1 wire was used, shortened to a neat length by shaping coils around a 1 cm diameter wooden dowel. This prototype works but future improvements plan to add automatic temperature control through a thermocouple and a relay.
[Buddy Smith] sent us a link to Open3DP which he calls “REAL 3d printing hacks”. Open3DP showcases the projects of the Solheim Rapid Prototyping Laboratory at the University of Washington. They’re working on 3D printing in materials that can be commonly acquired and to that end they publish recipes for powder printing in materials such as sugar, ceramic, and glass. Take a look through their archives. We found the post on microwave kilns interesting, as well as the writeup about Shapeways glass printing which is seen above. We’ve also embedded a short video on Open3DP’s work after the break.
Update: [Mark Ganter] dropped us a line to clarify that Open3DP was the first to develop printable glass about a year ago, called Vitraglyphic. They’ll also be presenting papers at Rapid2010 and announcing a new printable material.
Continue reading “Open3DP looks at 3D printing in common materials”