A Folding Laser Cutter

Want a laser cutter, but don’t have the space for one? How about a portable machine to engrave and cut wood and plastics? A folding laser cutter solves these problems, and that’s exactly what Red Ant Lasers was showing off last weekend at Maker Faire.

Inside the team’s Origami laser cutter is a 40 Watt CO2 tube, shooting its beam along an entirely enclosed beam path. The beam travels through the body of the machine, out into the folding arm of the machine, and down to whatever material you’ve placed the Origami on. It’s a 40 Watt laser so it will cut plywood and plastics, and as shown in the video above, does a fine job at engraving plywood.

This is a Class 4 laser device operating without any safety glass, but from the short time I spent with the Red Ant team, this is a reasonably safe device. You will need safety glasses if you’re within five feet, but after that, everything (according to OSHA, I think) is safe and not dangerous. Either way, it’s a tool just like a table saw. You don’t see commentors on the Internet complaining about how a spinning metal blade is dangerous all the time, do you?

The Red Ant guys are currently running a Kickstarter for their project, with a complete unit going for $4200. It’s pricier than a lot of other lasers, but not being constrained by the size of a laser cutters enclosure does open up a few interesting possibilities. You could conceivably cut a 4×8 sheet of plywood with this thing, and exceptionally large engravings start looking easy when you have a portable laser cutter.

Cryogenic Machining: Custom Rubber Parts

Cryogenic Machining Custom Rubber Parts

Fashioning a custom, one-off rubber part for your project isn’t usually an option, but [Ben Krasnow] has an alternative to injection molding and casting: machining frozen rubber.

As [Ben] points out, you can’t exactly pop a sheet of rubber on your mill and CNC the needed shape; the bit will push the material around rather than cut it. Freezing the rubber first, however, allows you to carve into the now-hardened material.

His initial setup consisted of a sheet of aluminum with water drizzled on top, a square of neoprene placed on the water, and a steady stream of -60 to -80C alcohol flowing directly onto the rubber. The water underneath freezes, holding the neoprene in place. This proved problematic as the ice-clamp gives way before the milling is complete. [Ben] later adds some bolts to clamp the pieces down, allowing the milling process finish as planned.

A small plastic tray sits underneath this assembly to capture the alcohol as it runs off, feeding it back with some tubing. [Ben] recommends against a submersible aquarium pump—his initial choice—because the pump stopped working after a few minutes immersed in the chilly alcohol. An external, magnetically-driven pump solved the problem although it does require manual priming.

Stick around after the jump for the video and check out some of [Ben's] other projects, like his quest for the perfect cookie, or CT scanning a turkey.

[Read more...]

Low Cost Lab Frequency Reference

The internals of a home built 10 MHz frequency reference.

[Mark] wanted an accurate frequency reference for his electronics lab. He specified some requirements for the project, including portability, ability to work inside a building, and low cost. That ruled out GPS, cesium standard clocks, rubidium standard clocks, and left him looking for a low cost Oven Controlled Crystal Oscillator (OCXO).

The Low Cost 10 MHz Frequency Reference is based around a Morion OCXO. These Russian oscillators are available from eBay second hand at about $40 a pop. With a stability well within the requirements, [Mark] order a few.

The next step was to stick all the components in a box. The two OCXOs in the box need about 3 amps to heat up, which is provided by a 12 V PSU. For portability, a sealed lead acid battery was added. The front panel shows the supply voltages, switches between mains and battery supplies, and provides connectivity to the OCXOs.

Since OCXOs work by heating a crystal to a specific temperature, they can use quite a bit of power in the heating element. To increase battery life, a neoprene foam insulator was wrapped around the OCXOs.

For less than $100, this portable tool will aid in calibrating equipment or creating very accurate clocks.

Lantern Made In Preparation of Zombie Apocalypse

DIY Lantern

[BenN] was at his local hackerspace one day when a friend stopped by and offered him a used 5AH lead acid battery. As any good tinkerer would, he jumped on the opportunity and immediately started looking around for a project to use the battery in. One of [BenN’s] recent other projects involved 12volt landscaping lights, the same voltage as the battery he was just given. At this point it was clear that he had a good start to making a lantern. This lantern project also supports [BenN’s] obsession with hobby of preparing for the zombie apocalypse.

A lantern needs an enclosure. Over on the hackerspace’s spare-parts rack was an old ATX power supply. All of the internal electrical components were removed to make room for the battery which fit inside nicely. The landscaping light just happened to be slightly larger than the power supply’s fan cut outs. Once the grill was removed from the metal power supply enclosure, the lamp fit in nicely and was secured using silicone glue which can tolerate any temperature the bulb can produce.

The feature that separates a lantern from a flashlight is the top-mounted carrying handle and this lantern will receive one made from the wiring removed from the ATX power supply. The electrical wiring is fairly straight forward. The battery is connected to the landscaping light by way of the original ATX on/off switch. The two terminals of the battery were also wired to the power supply’s AC input connector. This allows [BenN] to connect a DC battery charger to two of the three pins in order to charge the battery. Although this is a creative way to re-use the AC connector, it leaves quite a bit of potential to accidently plug in a 120v AC cord!

 

Energia on the CC3200

The CC3200 dev board with Energia

If you’re looking to connect things to the internet, with the goal of building some sort of “Internet of Things,” the new CC3200 chip from TI is an interesting option. Now you can get started quickly with the Energia development environment for the CC3200.

We discussed the CC3200 previously on Hackaday. The chip gives you an ARM Cortex M4 processor with a built-in WiFi stack and radio. It supports things like web servers and SSL out of the box.

Energia is an Arduino-like development environment for TI chips. It makes writing firmware for these devices easier, since a lot of the work is already done. The collection of libraries aids in getting prototypes running quickly. You can even debug Energia sketches using TI’s fully featured IDE.

With this new release of Energia, the existing Energia WiFi library supports the built-in WiFi radio on the CC3200. This should make prototyping of WiFi devices easier, and cheaper since the CC3200 Launchpad retails for $30.

Volumetric Circuits

5869061407871295021Building a circuit Manhattan style with small bits of copper and solder is a skill all its own, and building a prototype dead bug style is close to a black art. [Anderson] is taking it to the next level with his volumetric circuits. Not only is he building a free-form circuit that’s also a one-bit ALU, he’s also designing software to make these sort of circuits easy to design and build.

[Anderson] is calling his 3D circuit design software Pyrite, and it does exactly what it says on the tin: creates three-dimensional, grid-aligned physical circuits. Automating the construction of a circuit  is not a trivial task, and soldering all these components together even more so.

With the first prototype of his software, [Anderson] entered the schematic of a simple one bit ALU. The resulting layout was then carefully pieced together with solder and hot glue. It didn’t work, but that’s only because the schematic was wrong. Designing the software is still an incredible accomplishment, and now that [Anderson] has a rudimentary system of automatically designing free form and dead bug circuits, there are a lot of interesting possibilities. Ever wonder if the point to point wiring found in old radios was the most efficient layout? [Anderson] could probably tell you.

You can check out a few videos of [Anderson]‘s work below.

[Read more...]

DIY Powder Coating Oven Gets Things Cooking

diy-powder-oven

[Bob] needed an oven for powder coating metal parts. Commercial ovens can cost thousands of dollars, which [Bob] didn’t have. He did have an rusty old file cabinet though.  And thus, a plan was born. The file cabinet’s steel shell would make a perfect oven body. He just had to remove all the drawers, sliders, and anything combustible. A few minutes with an angle grinder made quick work of the sheet metal. The drawer fronts we re-attached with hinges, allowing the newly fashioned door to swing out-of-the-way while parts are loaded into the oven.

The oven’s heating elements are two converted electric space heaters. The heating elements can be individually switched off to vary power to the oven. When all the elements are running, the oven pulls around 2000 watts, though full power is only used for pre-heating.

[Bob] used a lot of pop rivets in while building this oven, and plenty of them went into attaching sheet metal guards to protect the outside of the heating units. To complete the electrical equipment, a small fan was placed on top of the oven to circulate the air inside.

The most important part of the build was insulation. The entire inside of the oven was coated with aluminum foil and sealed with heat proof aluminum tape. On top of that went two layers of fiberglass matting. Metal strips kept the fiberglass in place, and the stays were held down with rivets. One last layer of aluminum foil was laid down on top of the fiberglass. Curing powder coating produces some nasty gasses, so [Bob] sealed the gaps of the oven with rolled fiberglass matting covered by aluminum foil and tape.

[Bob] was a bit worried about the outside of the oven getting hot enough to start a fire. There were no such problems though. The fiberglass matting makes for an extremely good insulator. So good that the oven goes from room temperature to 400 °F in just 5 minutes. After an hour of operation, the oven skin is just warm to the touch.

If you need to find [Bob], he’ll be out in his workshop – cooking up some fresh powder coated parts.

 

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