Cutting Styrofoam With A CNC Machine And Turning It Into Aluminum

November 20, 2012 by Brian Benchoff 17 Comments

One of the most popular ways of turning an object trapped inside the world of a computer into a real, metal object is the art of lost wax, or lost foam casting. In this process, a full-scale model of the object to be made in metal is crafted in either foam or wax, placed in a pile of sand, and burned away by molten metal.

[ptflea] over at the Bamberg, Germany hackerspace Backspace came up with a very clever build that automatically cuts foam into the desired shape, ready to be taken out to the backyard foundry. The build is based around an old flatbed scanner and a hot wire cutter. The old scanner conveniently had an equal number of steps per axis, so attaching an Adafruit motor shield and replacing the old control electronics was just an issue of finding the correct resistors.

Software control is provided by a Processing app [ptflea] whipped up and is able to carefully cut very delicate shapes that even the steadiest hand would have trouble with.

Making stuff out of styrofoam is cool and all, but the real goal for this project was setting things on fire and melting old heatsinks. The styrofoam molds were placed in a bucket full of sand, and the furnace – a few ytong bricks, a crucible, and a propane burner – started to melt some aluminum. The molten aluminum was poured onto the mold and after cooling, the makers of Backspace had a few very cool aluminum trinkets.

A nice build that is able to produce some very nice metal objects. We suspect, though, that a higher-density foam (something along the lines of blue or green insulation sheets, if they have those in Germany) could produce an even higher level of detail if you’d like to build your own.

Videos after the break.

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Melting Beer Cans And Building Engines

June 25, 2012 by Brian Benchoff 28 Comments

What do you do if you’ve got a fully equipped machine shop and you’re tired of taking old beer cans to the recycler? If you’re like [Brock], you’ll probably end up melting those cans down to build an engine.

After gathering 50 pounds of beer cans and melting them down into ingots of various sizes, [Brock] and company had a lot of aluminum and nothing to build. Eventually, someone got the idea to build an internal combustion engine out of these beer can ingots.

So far, the beer can engine crew has built two engines from these beer can ingots. The four-stroke engine started off as a 5-inch aluminum cube, bored and milled into something resembling an engine block. When [Brock] and the beer can engine team completed their four-stroke masterpiece, they had a water-cooled engine displacing 150cc with a single 2″ bore piston. The two-stroke engine is a much simpler affair with a 1 inch bore displacing 19cc.

Even though there’s no information at all covering the pottery kiln foundry used to melt the beer cans into ingots, it’s an amazing piece of work building and engine from the ground up.

You can check out a few videos of both engines after the break.

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Building A Foundry In Your Backyard

June 12, 2012 by Brian Benchoff 25 Comments

[th3BadWolf] has been wanting to build a foundry for some time now. Done right, it’s a very neat tool; it’s fairly easy to do aluminum castings, and if you’re clever enough a foundry can lead to building large machine tools such as a lathe or a mill. Anything worth doing is worth overdoing, so [BadWolf] is designing his foundry to melt 150 pounds of aluminum every 45 minutes.

The build began with a humble oil barrel. [th3BadWolf] cut the top off of the barrel and began lining the inside of the barrel with a ceramic blanket and refractory bricks. To hold this somewhat precarious assemblage of blanket and brick together, [BadWolf] is holding everything together with 3000° F cement.

The body of the furnace is nearly complete, but [BadWolf] still has to drill a few holes for the burner system. He’s going to start each burn with Propane, then move over to engine oil when the furnace gets hot enough. Truly an awesome project, and we can’t wait to see the results.