Linear Optical Encoder

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Optical encoders are nothing new; they can be found in everything from mice to printers. They’re great for allowing DC motors to know their exact position and even current direction. If this is sounding like old hat, it’s because we’ve shown you rotational versions before.

[Chris] uses the same concept, but produced a linear optical encoder instead of rotational. His setup is much like whats used in non stepper-motor CNC and RepRap mills, allowing ordinary DC motors to know their position within a plane. It’s a quick tutorial, but we liked the detail and it reminded us we need to finish that DC motor based mill thats still a pile of parts in the closet. Check out a video of [Chris’] in action after the break. Continue reading “Linear Optical Encoder”

Boombox Warns Construction Ahead

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[Sam] built himself a boom box using salvaged parts and a car stereo. The case was cut using a CNC router he had access to at his school. The front panel is cut from a “Construction Ahead” road sign. The size of the case is based roughly on the rotting enclosures from which he pulled the speakers. He’s included connectors for external speakers as well as a USB charging port. The unit is powered by a gel battery and is recharged using an automotive battery charger.

A boom box lets you take the party anywhere. We like this one because of the pop art feel of the finished project.

CNC Hot Wire Cutter From Scanners

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[Raul] built a CNC hot wire cutter that he uses for cutting shapes out of foam. His device uses two flat bed scanners to provide two planes of motion. One scanner arm has the foam mounted on it and provides the Y-axis movement. The other scanner has the hot wire mounted on it and provides the X-axis movement. The cutting wire is mounted on a flexed bow made from heavy gauge coat hanger wire.

He tapped into the logic board of one scanner to gain access to the motor movements. The other is connected through a couple of H-bridges. Both are controlled by an Atmel AVR ATmega128 which in turn takes its commands from a connection with a computer printer port. A python program uses vector graphic files in SVG format and traces the outline for cutting.

We’ve got a video of this in action after the break. At our request, [Raul] took some time to post a set of pictures and make comments on them. Thanks for the hard work and great job! Continue reading “CNC Hot Wire Cutter From Scanners”

CNC Router On The Way

[vimeo http://vimeo.com/7019823%5D

We love CNC hacks, so when [Jonny] sent in his nearly complete CNC router we were ecstatic. There are only a couple of posts thus far, and it takes some digging, but its pretty easy to understand his mindset and overall plan while making the CNC. It currently has full 3 axis movement and he replaced the previously dinky Harbor Freight Dremel with a much more powerful DeWalt that even Tim Taylor would be proud of. Software side of things he uses a combination of EMC2 and their collection of open source CAM codes. The project is coming along nicely and more updates are promised. Check out some more videos after the break. Continue reading “CNC Router On The Way”

Machining Gets Wet And Wild

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[Tyler] has had his electrochemical machining hack up for a while now. His final version uses a pump to move electrolyte out through the etching head and onto the workpiece. This keeps fresh electrolyte in the etching region and clears out the insoluble material. We see how this could be attached to a CNC system and used to etch PCBs without the use of a special inkjet printer, toner transfer, or laser etching machine.

[thanks Ian]

Pick-and-place Lego Prototyping

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[Ned] tipped us off about his project for a class at Carnegie Mellon. Utilizing a Denso 6-AOF robotic arm they have built a rapid prototyping machine that uses Lego as the building material. LDraw, the open standard Lego CAD program, is used to build a model which is then translated into MATLAB files that the robotic arm can use for placement commands. Right now pieces need to be placed on a template for the robot to find and pick up.

It’s great that Lego pieces are used because they are readily available and inexpensive, but this type of precision robot makes the project unattainable for most tinkerers. Still, the concept is interesting and we could see an end goal being a more widely available machine. It’s not too much of a leap to image a RepRap type machine that takes internal measurements of a circuit board and the components, calculates inside case dimensions, then builds a prototype enclosure from common Lego pieces.

Pong On Your Wrist

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[John] wanted to take a pong clock and put it in a wristwatch form factor. Take an afternoon and pour over his detailed build logs. This multi-year project is done with meticulous cleanliness that makes us jealous. He’s milled the case and buttons himself, achieving a professional look that equals or surpasses the quality of some commercially available “gaming” watches. The project centers around an OLED display driven by a TI MSP430F2013 processor. Don’t miss the video after the break covering prototyping, PCB work, case milling, and the watch in action. Currently, this is the third generation of development but with a project this exciting, are you ever really finished? Continue reading “Pong On Your Wrist”