Snap-together PCB mill

[Jonathan Ward] came up with the MTM Snap, a snap-together pcb mill as part of the Machines That Make group at MIT.

We covered [Jonathan]‘s previous work made out of half-inch plywood, but the new iteration of his PCB includes a clever snap-together mechanism instead of screws and bolts. Although the MTM Snap looks a lot like3d printers such as a reprap, the similarities end with the off-the-shelf stepper motors. Instead of using motor drivers and control electronics from a reprap, the project uses custom stepper drivers, controlled by a bare Arduino.

We’re really impressed with the results of the MTM Snap compared with what is possible on a reprap-derived milling machine like a makerbot or wolfstrap. We’re thinking that’s due to the mass of this project compared to the printed ABS parts of the ‘common’ 3d printers, but any MEs are more than happy to correct that notion.

Check out the video after the break to see the machine in action and a great view of the snap-fit mechanism.

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Trick mouse keeps the screen saver at bay


[Jerry] wrote in to share a little device he built to solve a problem he was having at work. You see, every computer in his office has a policy-enforced idle timeout, requiring the user to enter a password in order to regain access to their desktop.

This is a huge pain, since he sporadically uses an old computer for the sole purpose of monitoring some applications running in his data center. With the computer timing out every 10 minutes, he is constantly required to enter his password in order to take a 10 second glance at the screen to ensure everything is OK.

Rather than circumvent the screen saver using a local security policy or by implementing a microcontroller-based signal generator, he opted to create a mechanical solution instead. His computer’s optical mouse resides inside a wooden frame, and is periodically swept from side to side by an ATmega-controlled servo, keeping the screensaver permanently at bay.

Call it a hack, call it a kludge, call it what you will. All we know is that while we might have done it a little differently, it works just fine for [Jerry], and it generates all sorts of interesting conversation to boot.

Stick around for a quick video demonstration of his mouse wiggler box.

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